May, 2000

EAST LANSING, Mich. – At the peak of the growing season, gardening questions are as common as weeds. Michigan State University Extension specialists answer timely queries on insects, lawn care, perennial and annual flowers, and related lawn and garden topics.

Q. What’s the best way to store gasoline for lawn mowers and other gasoline-powered equipment used around the yard?

A. Store small amounts (2 to 5 gallons) of gasoline only in approved containers. Store it in a separate storage shed, not in the garage or basement, and away from potential sources of ignition, such as a pilot light on a water heater or furnace, electric motors that might produce a spark or any open flame. Refuel gas-powered equipment outdoors after letting the engine cool. Avoid breathing gasoline fumes and never siphon gasoline by mouth. Using fuel-stabilizing additives can extend fuel quality during storage.

Q. How do cicadas make their buzzing sound?

A. Male cicadas have a pair of organs on the first segment of the abdomen. Each is basically a cavity with a lid. Inside is a membrane called a tymbal. The insect uses its muscles to make this membrane vibrate. This vibration creates the buzz, which the male uses to attract a mate.

Q. What makes those cone-shaped depressions in the sand that I see up north?

A. These depressions are traps made by ant lion larvae to capture prey. This lacewing relative digs a conical pit in the sand with itself buried at the bottom. Only its pincerlike jaws stick out of the sand, ready to capture any prey that slides down the loose sand and suck out its body fluids. Another name for ant lion larvae is doodlebugs. Ants are their most common food. Ant lion larvae are about ¼ inch long with spiny, segmented bodies and oversized pincerlike mouthparts; their pits may be ¼ to ½ inch deep and up to 1½ inches in diameter. In dry sandy areas, a square yard of soil may be dimpled with a dozen or more.

Q. What can I plant to attract butterflies to my garden?

A. The all-time greatest butterfly flowers include asters, Joe-pye weed, black-eyed Susan, butterfly bush (buddleia), liatris, butterfly weed (Asclepias spp.), coreopsis, purple coneflower and milkweed. You can also attract butterflies that typically don’t feed on flower nectar by providing plants for their larvae to feed on. Favorite larval host plants include asters, clover, hollyhock, lupine, mallow, marigold, milkweed, nettles/thistles, parsley, Queen Anne’s lace, plantain, snapdragon, sorrel, turtlehead and violet. Plants in the cabbage family are favorite larval host plants of cabbage butterflies, but gardeners usually aren’t inclined to share their broccoli and generally consider these caterpillars as pests.

Q. What tunnels in my iris rhizomes in the summer?

A. The aptly named iris borer is the larva of a moth that lays eggs in iris foliage in late summer or fall. When the eggs hatch, the larvae chew their way into the leaves and then down through the stem into the rhizome, where they feed and grow until midsummer. Damaged rhizomes usually develop a secondary rot that makes them soft and mushy. Control is simple: remove all old foliage in the fall or early spring and destroy it, along with any eggs that might be present. Another control

opportunity is in late summer. Dig iris rhizomes and destroy any containing borers. Check the soil around damaged rhizomes for the chestnut-brown pupae and destroy any that you find. This will reduce the number of adults laying eggs on your plants this fall.

Q. Why does my neighbor cut back her petunias and marigolds in midsummer and remove the flower buds from her chrysanthemums?

A. Cutting back flowering annuals such as petunias, coleus and marigolds in midsummer removes long, leggy stems and developing seeds and promotes flowering. Simply cut plants to about half-size with hedge shears or rose nippers, fertilize and water. They’ll look a little ragged for a while, but they’ll be much more attractive soon. Chrysanthemums are perennial plants rather than annuals, but they, too, benefit from having their stem tips -- including flower buds -- removed two or three times in early summer. This pinching, as it’s called, promotes branching and makes for a bushier plant with more flowers in the fall.

Q. My kids and I watched a praying mantis egg mass hatch, and the hatchlings immediately started eating one another! This makes me wonder just how effective it would be to put egg cases in your garden for pest control.

A. The praying mantis is a predator that consumes many prey every day. It’s not selective in what it eats, however, so it’s as likely to chow down on beneficial insects as on pests. As you noticed, mantids are ready to eat as soon as they hatch and will eat their siblings if that’s what’s

available. Camouflage coloration, a neck that allows the mantid to turn its head to spot its prey, large eyes, and forelegs well designed to grasp and hold prey make mantids efficient and effective at ambushing other insects. But because they don’t target pests, they aren’t a big help with pest control.

Q. I’m looking for a failsafe perennial for a partially shaded, sort of dry area. Any suggestions?

A. The first thing to come to mind is daylilies. They tolerate a wide range of soils, grow well in full sun or shade, need little care, multiply themselves, grow vigorously, bloom profusely and overwinter year after year. Each blossom lasts only one day, but established plants can produce literally hundreds of buds and so can remain in flower for a month or longer. Late summer or early fall is a good time to plant them.

#lkj#

ANR Communications Contact: L. Johnson or T. Ellis
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 355-8478
East Lansing, MI 48824-1039 5/19/00

BUG ZAPPERS KILL INSECTS, BUT
PROBABLY NOT THE ONES YOU WANT DEAD

EAST LANSING, Mich. -- Some people consider the crackling, popping noises from a backyard bug zapper distasteful. To others, it’s music to their ears.

To Extension entomologist Tom Ellis at Michigan State University, the music is somewhat out of tune.

"It’s true that bug zappers attract many flying insects to their death on the electrified grid," Ellis says, "but they are not effective at ridding the area of the biting pests that people expect them to eliminate. In fact, they may attract insects into your yard that otherwise wouldn’t be there."

Bug zappers use black light to lure insects in close. The majority of the insects killed are harmless night-flying moths, mayflies, beetles, non-biting gnats and other non-pests. They can become nuisances, however, if the bug zapper is placed by the patio, near the back door or at one corner of the deck.

"If people would think about how these things work, they’d place them as far from the outdoor living space as possible," Ellis suggests. "They’re going to attract hordes of insects, and harmless or not, no one trying to cool off on the deck on a warm summer night wants to be at the center of a swirling cloud of bugs."

People who buy these devices usually do so in hopes of reducing mosquito numbers. Mosquitoes, however, are not attracted at all by black light but rather by the carbon dioxide given off by a potential bite victim, Ellis points out. If there are people outside, any mosquitoes flying into the yard will quickly home in on the promise of a blood meal.

Other biting insects, such as horse flies and other biting flies, don’t work nights, so they aren’t attracted to a black light trap.

"Even if the insects you wanted to eliminate were attracted to the device, you couldn’t keep an area insect free unless you could enclose it," Ellis says. "New insects are always coming into your yard from outside -- especially if you have a black light out there to attract them. Bug zappers actually increase the number of insects flying into your yard. Tests have conclusively shown that there are more insects flying around when a bug zapper is in use."

A big selling point of these devices is that they kill insects without toxic chemicals or mess.

"They also pose no particular threat to the pests you want to control," Ellis points out. "Repellents or backyard foggers for temporary control of biting insects might give the results hoped for from an electronic bug zapper at a fraction of the cost."

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

FOR POTPOURRI MAKINGS,
LOOK INDOORS AND OUT

EAST LANSING, Mich. -- Potpourris, those aromatic mixtures of dried plant materials, are easy and inexpensive to make, and many of the ingredients can be found in your garden, in woods and fields, and in your own kitchen.

The basics of potpourris are few, says Mary McLellan, Master Gardener program coordinator at Michigan State University. They are aromatic plant materials, thoroughly dried; decorative plant materials, thoroughly dried; other aromatic ingredients, such as whole spices, chips of pleasant-smelling wood and bits of citrus peel; essential oils; and fixative, which combines with the essential oils to preserve their fragrance.

Except for the fixative and essential oils, most of the ingredients are free for the picking.

Aromatic plant materials include such things as rose petals, marigold flowers and foliage, scented geraniums, lavender, mints, fragrant herbs of all kinds and evergreen needles.

"You can use almost any plant material for its scent, color or shape," McLellan notes, "as long as it’s thoroughly dried so your mixture doesn’t mold."

Dry by hanging plant materials upside-down in bunches in a cool, well ventilated area, spreading them on paper towels in a well ventilated spot out of direct sun, or placing them between layers of paper towels in a microwave oven. Then combine them with whole cloves or stick cinnamon, bits of cedar bark, and visually interesting items such as gum tree seed pods and pine cones.

To this mixture you then add a fixative and a few drops of a compatible essential oil for a stronger, longer lasting scent than the dried ingredients alone can provide, McLellan explains.

The most common fixative is orris root, which should be available wherever you purchase the essential oils. It’s sold in powdered or chunk form. Chunks tend to be effective longer and work better in sachets or pillows because they can’t sift through the fabric as the powdered form can.

Because materials have to be collected and dried, making potpourri from gathered materials is not a spur-of-the-moment project, McLellan observes. On the other hand, you don’t have to wait for a particular time to start collecting -- you can start accumulating the dried ingredients anytime. Needles from a discarded Christmas tree can be the beginning. Then rose petals from a Valentine’s Day or Mother’s Day bouquet, marigolds from the garden, Queen Anne’s lace from the roadside, bittersweet berries from a backyard vine, chrysanthemum blossoms, weed seeds and pine cones -- collect whenever the opportunity presents itself. Then dry the materials and store them in tightly sealed glass containers (canning jars are good) in a spot where they’ll be protected from heat and sunlight.

Mix the desired materials in a glass or ceramic bowl or a sturdy plastic bag. Follow a recipe or invent your own. Be sure to write down the ingredients and the quantities you use in case you ever want to recreate a given mixture, McLellan suggests.

Stir the mixture with a wooden spoon or shake it gently in the plastic bag. Then put it in jars, along with the fixative and essential oil, close the jars and shake well. Label and store in a cool, dry place and shake daily.

Let the potpourri age for at least a month before you use it, she suggests. If the scent is fainter than you want, put another drop or two of oil on a little fixative, add it to the mixture, shake and age some more.

Potpourri is often placed in cloth bags or sachets for use in closets and dresser drawers. It can also be used in shallow bowls or decorative glass containers to add fragrance to a room. This is where visually interesting items such as strawflowers, Queen Anne’s lace flowers, dried berries, seed pods and cones come into the picture. They make the mixture pleasing to the eye as well as the nose.

#lkj#

ANR Communications Contact: L. Johnson or T. Ellis
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 355-8478
East Lansing, MI 48824-1039 5/19/00

HARD TO PINPOINT CAUSE
OF INSECT OUTBREAKS

EAST LANSING, Mich. -- One year, it’s Japanese beetles -- they’re everywhere! Another year, it’s earwigs or a host of hungry caterpillars in your backyard oak trees.

Insect outbreaks like these can be distressing, observes Tom Ellis, Extension entomologist at Michigan State University.

"They seem to come out of nowhere and, in the case of Japanese beetles and hardwood defoliating caterpillars, they eat their way through plants we care about," he observes. "Often, by the time the damage is evident, it’s too late to take action to protect plants, so homeowners are left wondering why the outbreak occurred and whether they could have done anything to prevent it."

So many factors enter into an insect outbreak that it’s hard to pinpoint any one cause, Ellis points out.

"Most of the time, a combination of weather, predators and parasites, and disease organisms keep pest populations in check so we don’t even notice them," he says. "Then something happens -- maybe we spray a pesticide that kills off the predators that were keeping a pest population under control. Or maybe the weather isn’t favorable for the spread of a fungus that causes a disease that ordinarily kills a large percentage of the larval stage. If more survive to become reproducing adults, more eggs are laid, which means more larvae. Unless something kicks in to control the pest at some point, the result is a population boom."

It doesn’t require much of a change in the survival of eggs or larvae to make a terrific increase in the pest population, Ellis notes. Say the female lays 500 eggs. It takes only one male and one female out of those 500 to survive to maintain the population. That’s only a .4 percent survival rate. To put it another way, 99.6 percent of the eggs and larvae can die without reducing the total population.

Lower the mortality rate another 1 percent -- 98.6 percent of the young die -- and you increase the population by 3.5 times. Reduce it to 95 percent and you increase the population by 12.5 times.

"Because we’re talking about only a few individuals to start with, it’s easy to see that it wouldn’t take much of a change in the environment to cause a big change in the local insect population," Ellis says.

A boom doesn’t occur overnight, though it may seem that way because we don’t notice the increasing numbers until populations become quite large. At that point, natural controls have also been building and usually cause the booming population to crash after a year or so. The pests that were so numerous seem to disappear as mysteriously as they arrived.

The gypsy moth has been an exception to this boom and bust cycle because it’s been expanding into new areas where natural controls weren’t in place, Ellis notes. In some areas, one outbreak year after another has occurred. Diseases, parasites and predators, some of them introduced by people to slow the spread and reduce the impact of the pest, are making their presence known, however, and a more natural cycle is becoming established. In the meantime, gypsy moth outbreaks show what a difference the absence of built-in natural controls makes in the local pest situation.

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

HERBS DO BEST
WITHOUT MUCH TLC

EAST LANSING, Mich. -- Like most vegetable crops and many annual flowers, most herbs grow best in a sunny location with well drained soil. Unlike these other plants, however, herbs often thrive in less fertile, dry soil. In fact, if they get too much nitrogen from fertilizer or manure, they tend to lose their characteristic flavors and aromas.

Most gardeners grow culinary herbs -- those for cooking -- such as dill, basil, rosemary and chives, observes Mary McLellan, Master Gardener program coordinator at Michigan State University. As interest in herbal medicines grows, many gardeners are growing medicinal herbs, as well as fragrant herbs for use in potpourris and sachets.

"Herbs can be ornamental, too," McLellan points out. "Some of the scented geraniums make excellent hanging basket plants. Lavender is a long-time favorite in the perennials garden, and curly-leaved parsley makes an attractive dark green edging in the annuals garden."

Some herbs are annuals -- they grow from seed and produce seed in the same year. Popular annual herbs include sweet basil, borage and dill. Others are biennials -- plants that take two years to grow and produce seed. Caraway, sweet marjoram and parsley are biennials. Others are perennials -- plants that persist for several years, growing new tops from the roots each year. The majority of herb plants fall in this category.

Gardeners generally seed herbs directly into the garden in the spring, though many types are available as transplants.

Some annual herbs will self-seed. Dill can become a nuisance weed this way, McLellan notes. Members of the mint family can become pests by spreading into areas where they aren’t wanted.

Harvest time varies according to the part of the plant that is harvested. Seeds must be allowed to ripen but must be harvested before the seed heads shatter. The leaves of parsley and chives and some others are harvested for fresh use as soon as plants are big enough to spare a few. Rosemary and thyme are harvested at full bloom; basil, fennel, mint, sage and summer savory are harvested after they flower.

Long stems and whole plants can be hung upside-down in bunches in a warm, well ventilated location to dry. Short-stemmed herbs, flowers and seeds can be spread on a screen to air dry or dried between paper towels in a microwave.

Store dried herbs in tightly covered jars in a dark, cool location, McLellan advises. If moisture condenses inside the jars, more drying is needed.

Some herbs will grow on a sunny windowsill over the winter, she notes.

"If you want to try this, it’s a good idea to start with new plants grown from seed or healthy cuttings or divisions from garden plants," she suggests. "Use a well drained potting mix rather than soil from the garden."

Chives, mints, parsley, basil, sweet marjoram and rosemary are usually good choices for a windowsill herb garden.

#lkj#

ANR Communications Contact: L. Johnson or T. Ellis
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 355-8478
East Lansing, MI 48824-1039 5/19/00

IF IT’S GREEN, JAPANESE BEETLE
WILL LIKELY EAT IT

EAST LANSING, Mich. --Midsummer is the time when flower gardeners and others who put a lot of sweat and inspiration into their backyard flora really start to enjoy the fruits of their spring and early summer labor. In some areas of Michigan, this enjoyment has been all but ruined the past couple of summers by an iridescent green beetle that will eat almost anything green, including many flowers, petals and all! "Japanese beetle adults have insatiable appetites, will eat a wide variety of plants common to yard landscapes and travel in large swarms while on the wing," says Tom Ellis, Extension entomologist at Michigan State University.

Japanese beetle adults emerge from mid-June to early July. They feed on a variety of foliage -- fruit trees, roses, basswood and wild grape are favorites -- until late July or early August. At that time, they move to grassy areas and lay eggs.

In mid-August, tiny grubs hatch and feed throughout autumn, reaching a length of 1/2 to 1 inch. In areas that are heavily infested, feeding grubs cause root-pruning damage to turf. In October, when soil temperatures begin to drop, the C-shaped larvae move deeper in the soil to overwinter.

"Do not spray until you see the green of their elytra (wing covers)," Ellis advises.

In other words, spraying before you see Japanese beetles to prevent them from damaging your plants is not logical, and spraying after they have fed and left (revenge spraying) does no good, either. Doing either will likely cause more problems than it cures by killing beneficial predators and parasites that may be controlling other would-be pests.

Adult Japanese beetles will move in, feed until they get their fill and move on, so to catch them in the act of munching your plants, you need to monitor your backyard plants daily, if possible. If the beetles show up, spray them with an insecticide registered for that use. Carbaryl, Bendiocarb, Malathion, insecticidal soap and Neem all work fairly well. In fact, some research indicates that Neem (a natural product) has some repellent qualities. Keep monitoring, Ellis urges, because another group might move into your yard tomorrow. Repeat spraying as beetles appear. This might be as frequent as every couple of days. Read and heed all instructions regarding application and safety on the insecticide label if you do the application yourself. Phytotoxicity (toxicity to plants) is a rare event but possible.

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

IN DRY WEATHER, WATERING
MORE CRITICAL FOR SOME PLANTS

EAST LANSING, Mich. -- Before spring had hardly sprung, climatologists were talking about the potential for drought this summer. Whether those predictions come true or not, every summer has its dry periods when watering is necessary.

Watering is more critical for some plants than others, observes Mary McLellan, Master Gardener program coordinator at Michigan State University. If your ability to water the plants in your landscape is limited, setting watering priorities guarantees that the plants that have the most critical need get water first, she suggests.

Top priority are newly planted lawns, trees and shrubs. These plants haven’t established extensive root systems, so they can’t survive long periods of dry weather. They’d also be expensive to replace, so if rain is scarce, you must irrigate.

Priority No. 2 is trees and shrubs planted within the past two or three years. Though they’re not as vulnerable to drought as newly planted ornamentals, they still don’t have the established root systems of older plants. In severe drought, plants up to five or six years old may need watering to survive.

The next priority is flowers, vegetable gardens and older landscape plants.

"Though flowers and vegetables may show the effects of dry weather sooner and more dramatically than some other plants, the relatively low cost of establishing them relegates them to a lower spot on the priority list," McLellan says. "Mulching to slow the loss of soil moisture can reduce the need to water and control weeds, also, which can rob desirable plants of available moisture and nutrients."

Older, established woody ornamentals can vary in their need for irrigation, she observes. Birch and dogwood are among those more susceptible to drought; oaks, hickory, honeylocust, Norway maple, and white and green ash tend to be more drought-resistant. Plants under attack by defoliating pests such as gypsy moth or birch leafminer will need supplemental water more than unstressed plants.

Healthy, established lawns have a built-in protection against drought -- plants go dormant. The lawn may turn brown, but it’ll green up and grow again when conditions improve. Keeping a lawn growing and green during hot, dry weather requires watering every two to three days.

Newly transplanted flowers and vegetables and newly seeded lawns require frequent, shallow watering. Other plants do better with deep watering, which encourages the formation of large, deep root systems that help plants withstand dry weather. To water trees and shrubs, place a trickling hose placed near the base of the plant or, for large trees, let the hose trickle at several locations within the dripline. In this case, watering may take three or four hours. A trickle irrigation system or a soaker hose placed upside-down in vegetable or flower beds is more efficient than a sprinkler. It applies water to the soil rather than throwing it up into the air to evaporate or applying it to plant foliage, where it can promote disease development.

The rule of thumb for watering is an inch of water per week from rain, rain and irrigation, or irrigation alone, McLellan notes. Soil type enters into the calculation. Plants on sandy soils need more; plants exposed to hot, drying winds will also need more. Plants on heavy clay soils may need their inch applied in more than one watering session so the water has a chance to soak in rather than run off.

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

LOOKING FOR CAUSE OF GARDEN
PROBLEMS? TRY THE MIRROR

EAST LANSING, Mich. -- Even if you’re too young to remember the comic strip "Pogo", you’ve probably heard it quoted: "We have met the enemy, and he is us."

It’s not very grammatical, but it pinpoints the cause of many garden or landscape plant problems: the gardener.

"Many plants have problems because someone planted them in an unsuitable site," observes Mary McLellan, Master Gardener program coordinator at Michigan State University. "Picking species and varieties that are adapted to the local climate and choosing a site that provides the growing conditions they need can go a long way to reduce potential problems," she adds.

Some plants native to warmer climates simply can’t survive an ordinary Michigan winter, she points out. Planted in a protected site, they might survive -- but not thrive -- for a while, until a colder than usual winter kills them.

Many insect and disease problems can be traced back to poor plant or site selection, she points out.

"Poorly drained soil, too much shade or low soil fertility can stress a plant," she explains. "This makes it more susceptible to attack by insects and disease organisms."

Other examples of poor plant/site combinations include fruit trees, grapes, dogwood trees or rhododendrons planted in a low-lying area where early spring frost will be a problem, and evergreen shrubs planted in a spot exposed to winter sun and wind or flying salt spray. In the former case, flower buds will likely be frosted most years; in the latter, drying sun and wind will damage foliage and salt spray will kill foliage and twigs and, if it builds up in the soil, roots.

Where plants are planted is not the only issue -- how they’re planted also makes a difference. Proper planting procedures help plants get off to a good start in the landscape, McLellan observes. Planting annual or perennial flowers or vegetables in the evening or on a cool, cloudy day reduces transplant shock. Check the root balls of landscape trees and shrubs, she advises, and make sure you remove all wires, plastic burlap, plastic cords and any other materials that would restrict root growth or girdle the plant as it grows. Making sure the planting site provides plenty of room for the plant to reach its mature size without crowding buildings or other structures or other plants is another good idea. It reduces the need for drastic pruning to control plant size or removing the plant altogether.

Often gardeners can choose between plant varieties with built-in resistance to common plant diseases and susceptible varieties. A good year for apple scab is a bad year for susceptible apple and crabapple varieties, which usually lose their leaves to the disease by midsummer unless they’re sprayed frequently. The fruits are also deformed. Scab-resistant varieties can virtually eliminate scab as a concern and reduce or eliminate the need to spray ornamental trees for disease.

Some plant diseases can be spread by gardeners as they tend their yards and gardens. Smoking in the garden can introduce tobacco mosaic virus, which can infect tomatoes, peppers, eggplant and related plants, and can be spread from plant to plant simply by brushing against them. Working in the garden when foliage is wet increases the chance of moving disease organisms to plants when they’re most susceptible to infection, McLellan notes. Pruning landscape plants infected with bacterial diseases such asblack knot without disinfecting pruning tools between cuts can spread the organism from diseased to healthy tissue. Failing to clean up and burn diseased apple and rose foliage in the fall can promote the carryover of a host of fungal diseases, including black spot of roses and apple scab.

Other activities that can cause plant problems include misapplication of herbicides, fertilizers and other pesticides, and careless use of lawn mowers, string trimmers, and other lawn and garden equipment.

"A good way to prevent so-called ‘lawn mower blight’ in trees and shrubs is to surround them with a mulched area that doesn’t have to be mowed," McLellan suggests.

Some causes of plant problems -- particularly such things as hail, ice storms and high wind -- are outside the gardener’s control, she notes.

"So it makes sense not to be the cause of avoidable problems," she sums up.

#lkj#

ANR Communications Contact: L. Johnson or T. Ellis
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 355-8478
East Lansing, MI 48824-1039 5/19/00

MAY DEFOLIATE: LITTLE
BEETLES, BIG ELMS

EAST LANSING, Mich. -- From a distance, the elm tree canopy looks thin and brown. As we get closer, we can see that what’s left of the foliage looks like ragged, dirty brown lace. The ground is littered with the remains of fallen leaves.

It’s mid-July, and this Siberian elm tree has been hosting a thriving population of elm leaf beetles. These ¼-inch, hard-backed, yellowish to olive-colored insects and their black and yellow offspring both feed on elm leaves, says Tom Ellis, Extension entomologist at Michigan State University. They especially like Siberian elm, a quick-growing tree often sold for landscaping under the name Chinese elm. Adults eat roughly circular holes clear through leaves; larvae feed from the underside, leaving only the upper surface and veins. Damaged leaves turn brown. A severe infestation can defoliate these trees in midsummer.

Defoliated trees may put out a new flush of growth that may be consumed by other elm-feeding insects or by a second generation of elm leaf beetles.

"Feeding damage by elm leaf beetles seldom kills trees outright," Ellis observes. "It may weaken a tree, however, especially if it occurs several years in a row. The tree may then be more susceptible to attack by other insects or disease."

As if having elm leaf beetles munching your trees isn’t bad enough, the adults may seek winter shelter in attics, wall voids, garages and other protected places. Then when they emerge in the spring, they may bumble their way into homes in large numbers.

"Most homeowners aren’t keen on having their living space literally crawling with little hard-backed bugs," Ellis observes. "Control beetles in the home by sweeping them into a dustpan and dumping the contents into a container of soapy water. Let it set overnight, then dump the contents outdoors. Closing up insect entryways such as holes around incoming wires and cracks in foundations, walls and eaves can be tedious and time consuming, but it can be fairly effective at keeping a host of would-be winter houseguests outdoors."

Spraying the foundation walls, window wells, crawl spaces, door thresholds and other potential points of entry is another option. This may be almost as large a job as spraying elm trees to control the emerging larvae, a job that’s usually out of the scope of the homeowner, Ellis observes.

"Especially when you consider the value of a Siberian elm compared with, say, an oak tree, the cost of hiring a pest control firm to spray the elm may be prohibitive," he notes.

An alternative to spraying the foliage is to apply an insecticide to the lower trunk and the ground around an infested tree when beetle larvae start to move down the tree to the soil to pupate, Ellis suggests. This is usually in late May or early June in mid-Michigan. Though this doesn’t prevent damage by the first generation, it greatly reduces the number of larvae that will survive and reproduce.

A permanent solution to the beetle problem is to remove the tree and replace it with a more desirable species. In addition to beetle problems, Siberian elms are weak-wooded and prone to damage by wind and ice storms.

Homeowners looking for recommendations on landscape trees with fewer problems can find information at their county MSU Extension offices.

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

NEVER A SHORTAGE
OF WEED PROBLEMS

EAST LANSING, Mich. -- Bad weather can devastate your garden, but it’s unpredictable -- years may pass without a hailstorm or a killing frost in July or August.

Weeds, on the other hand, never fail to put in an appearance.

"Insects, diseases, browsing rabbits and deer, too much rain or not enough -- a host of problems can plague your garden," observes Mary McLellan, Master Gardener program coordinator at Michigan State University. "But year in and year out, the biggest problem that most gardeners face is weeds."

Weeds probably defeat more first-time gardeners than any other problem, she adds.

The first year can be the worst for several reasons.

When a garden spot is carved out of the lawn, the grass must be eliminated. You can apply herbicides or cover it with black plastic, old carpet or broken-down cardboard boxes, or remove the sod during the previous growing season. Failure to eliminate the grass sets the stage for a continuing battle against it as it tries to reclaim the garden spot.

Another common problem is overestimating the size of garden one can handle with the time, labor and equipment available. The weeds take over in June and the beleaguered gardener never catches up.

One strategy to prevent this is to figure out how big a garden you can deal with and then reduce it by half. Another is to remove the grass the year before and till the area every time it becomes carpeted with weed seedlings.

"Each tilling kills the seedlings that have recently emerged and brings new seeds to the surface," McLellan explains. "Those seeds germinate and the plants are killed by the next tilling. You never get rid of all the potential weed problems this way, but you can reduce them."

Vegetable gardens are planted in stages -- cool-weather crops from seeds, sets and transplants early; then warm-weather crops from seed; then more warm-weather crops from transplants; then, for a fall harvest, cool-weather crops and quick-maturing warm-weather crops in the space vacated by harvesting peas, salad vegetables and other early-planted crops. So another weed-fighting strategy is to work each area just before planting so seeds and transplants go into weed-free soil. This gives vegetables at least an even chance against weed seedlings.

Another tactic in the battle against the weeds is to get ‘em while they’re small.

"The bigger weeds get, the more time and effort it takes to get rid of them," McLellan sums up.

Hoeing or cultivating between rows and hills with a tiller can be very effective when weeds are small, but an all-out effort against large weeds may require running the lawn mower through first to cut them down to manageable size.

A significantly less laborious approach to weed control is mulching. Whether you use old carpeting, cardboard, black plastic or organic mulches such as straw, spoiled hay or compost, the aim is to cut off sunlight to weed seedlings. What you use may depend on what’s available. If you have a choice, you can base your decision on whether you want to be able to plow it down in the fall. Materials such as plastic and old carpeting have to be pulled up; organic mulches can be tilled in.

Mulching also helps conserve moisture by slowing the evaporation of water from the soil. It can also contribute to certain types of pest problems, such as slugs. On the other hand, it can also provide hiding places for predators such as spiders and ground beetles, which can help control pests. Organic mulches may also lessen problems with ground rots in crops such as tomatoes and squash by keeping fruits off the ground.

The main advantage, though, is the edge that mulching gives in annual weed control, McLellan points out. Perennial weeds can be tougher -- they need to be eliminated, usually with broad-spectrum herbicides such as Roundup, before you plant your garden. Repeated tilling is another option. Both are easier to do before crops are in place.

Though weed control seems more critical early in the season than later on, weed control needs to continue until the harvest ends, McLellan advises.

"Each weed that matures and produces seed means dozens or hundreds of weeds you’ll have to deal with next year," she explains.

#lkj#

ANR Communications Contact: L. Johnson or D. McCullough
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 355-7445
East Lansing, MI 48824-1039 5/19/00

NEW EXOTIC PEST
THREATENS BEECH TREES

EAST LANSING, Mich. -- Michigan’s beech trees are facing a serious threat from an exotic insect and a disease that have been known in the eastern United States for decades but were discovered in Michigan only this spring.

The threat is beech bark disease (BBD), caused by the interaction of a tiny scale insect (Cryptococcus fagisuga) with Nectria, a fungal pathogen. Deborah McCullough, Michigan State University Extension forest entomologist, says perhaps 1 percent of Michigan’s beech trees will prove resistant to the disease. The rest could be lost.

The threat to the beech tree begins when the scale attaches itself to the trunk or branches to feed on sap. As it feeds, the scale secretes a cottony material. The bark on a heavily infested tree will be covered with what looks like gray-white mold.

"The feeding by the scales will reduce the vigor of the trees, but the main problem is that the wounds they create allow the Nectria pathogen to enter the tree," McCullough explains.

The fungus causes cankers on the tree trunk and branches. Infected areas are killed and whole trees may die. More commonly, branches or the tree trunk will break at the point of the canker, McCullough says.

Beech bark disease was discovered in April in beech trees in the Ludington State Park in Mason County. After an extensive survey of that area in the spring and another survey this summer, entomologists from MSU, the Michigan Department of Natural Resources, the Michigan Department of Agriculture and the U.S. Forest Service will have an idea of the extent of the problem.

"We need this information to develop the best policy for managing the problem here in Michigan," says Robert Heyd, DNR forest entomologist.

Prospects for containing the disease are not hopeful, McCullough notes, because the scale insect and the fungus can be carried on the wind. Landscape trees can be treated with systemic insecticides to control the scale, though the treatment must be repeated and can be expensive. Little can be done to curb the disease in forestlands, however, except to cut down infected trees.

"Large trees can be salvaged and removed from the woodland, but young trees and root sprouts will also become infected," McCullough says.

The beech bark scale was accidentally introduced into Nova Scotia about 1890 and has since moved through most of eastern Canada, New England and Pennsylvania and into Tennessee. How it arrived in Michigan is still a mystery, though hitchhiking on firewood brought into the state from the Northeast or blowing in on the wind are possibilities.

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

PERENNIAL VINES HAVE MANY
ROLES IN THE LANDSCAPE

EAST LANSING, Mich. -- From ground cover to a quick screen to a striking floral display or textural interest on a blank wall -- vines can serve many landscape uses. The best vine for your needs depends on what function you want it to perform and the growing conditions at your proposed planting site.

Mary McLellan, Master Gardener program coordinator at Michigan State University, points out that how vines climb is another factor to consider. "Some vines climb by means of modified roots that look like tiny suction cups or aerial rootlets along the stems that work their way into crevices of a rough-textured surface," she points out. "These can be used on masonry walls but will damage wood surfaces." Others, such as the grape, climb by means of tendrils, slender, leafless stems that wrap themselves around whatever support is available. Twining vines climb by winding their stems around any available support. Neither of these will climb flat, vertical surfaces. Vines don’t always climb, however, McLellan notes. Hall’s honeysuckle, for example, is a semi-evergreen vine that can climb by twining, but it’s often used as a ground cover. It forms a dense mat of wiry stems and, from June to September, bears extremely fragrant white flowers that turn yellow.

"At MSU, honeysuckle is used for a ground cover only in areas surrounded on all sides by pavement," she notes. "This is necessary because it is a rampant grower and can easily grow into areas where it’s not wanted."

Honeysuckle grows best in full sun to light shade. It’s not choosy about soil types.

A shady, moist area is well suited to English ivy, an evergreen vine that will climb or creep along the ground. With a little protection against winter sun and wind -- such as that provided by a planting site on the north or east side of an evergreen hedge or a building -- the leathery leaves will hold their dark green color all winter. In a spot facing south or west, English ivy is likely to suffer winter burn.

No hummingbird garden is complete without a trumpet vine (Campsis radicans). It bears 3- to 4-inch orange, red or yellow flowers in late summer. Vines climb by aerial rootlets, often reaching 30 feet or more on masonry walls, wood posts or trellises. The showy flowers are very attractive to hummingbirds. Best flower production occurs on vines planted in full sun, McLellan notes.

Exotic-looking flowers are also the main attraction of clematis vines. Various cultivars provide single and double flowers in a wide range of colors -- with reds, pinks, purples and white predominating -- and sizes up to 6 inches in diameter. In contrast to the large-flowered types, sweet autumn clematis (Clematis paniculata) produces masses of small, fragrant white flowers in August and September. Flowering times for the other varieties can be anytime from late spring through the summer to frost. Some cultivars need annual pruning for good flower production. All climb by twining, grow best on a trellis in full sun and benefit from mulching to shade the roots.

Masses of blossoms in shades of white, blue and purple make the wisteria one of the most spectacular flowering vines. Chinese wisteria (Wisteria sinensis) bears 6- to 12-inch clusters of lilac or white flowers in May; the Japanese wisteria (Wisteria floribunda) bears 2- to 3-foot blue and white flower clusters two to three weeks later. Vines climb by twining. They get large and heavy and need sturdy support structures, McLellan advises. For maximum visual impact, they are often trained horizontally on a wire or structure 10 feet or more above the ground. Best flower production occurs in fall sun. Vines are often slow to flower -- even those propagated from cuttings may take several years to bloom (those grown from seed may take 15 to 20 years).

Some ornamental vines are grown more for their fruits than their flowers. American bittersweet (Celastrus scandens) will tolerate partial shade but does best on a trellis in full sun. Only female plants bear the orange or scarlet fruits in the fall, but both male and female plants are needed for fruit production. Like clematis, bittersweet grows by twining and requires some pruning, McLellan notes.

Winter creeper (Euonymus fortunei) is a broad-leaved evergreen with fruits similar to those of bittersweet. Because it climbs by means of holdfasts, it’s well suited to growing on a brick or other masonry wall. Its big drawback is its susceptibility to euonymus scale. An infestation may require treatment with dormant oil or a recommended pesticide.

Most of these vines grow vigorously enough to provide a quick screen, McLellan observes.

"Simply place a sturdy trellis or other support where you want your living screen to grow, then plant with care," she suggests. "Choose your vine carefully to avoid damage to your home or other structures from clinging rootlets or moisture trapped behind a thick mat of foliage. Select vines that use tendrils or twining to climb a trellis rather than ‘clinging vines’ that use holdfasts or aerial rootlets to latch onto flat surfaces."

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

PLANT COLE CROPS
FOR FALL HARVEST

EAST LANSING, Mich. -- Cabbage family plants usually grow and yield better when planted for a fall harvest. Transplants can be hard to find in midsummer, but they’re easy to grow from seed in the garden.

"Cabbage and kohlrabi grow well during the heat of the summer," observes Mary McLellan, Master Gardener program coordinator at Michigan State University. "But broccoli, cauliflower and Chinese cabbage do best in cool weather, so they can be planted in midsummer, after peas or some other early crop has been harvested. Brussels sprouts have a long growing season, so they’re planted in May but not harvested until after frost."

To grow your own transplants, sow seed directly in the garden in June. Seed will germinate quickly in the warm soil.

Mark rows carefully, McLellan advises, so you don’t accidentally till the seedlings under or mulch over them. Be sure to identify each crop, also -- seedlings of the various crops can be difficult to tell apart.

When seedlings reach the four- or six-leaf stage, they are ready to be transplanted. Space kohlrabi 8 inches apart; broccoli and Chinese cabbage 12 inches apart, and cauliflower 24 inches apart in rows 18 to 24 inches apart for kohlrabi and 24 to 30 inches apart for the others. A high-phosphorus starter fertilizer will help them get established quickly.

The biggest problem in growing these crops is usually insect pests, observes Tom Ellis, Extension entomologist at MSU. Cutworms may nip transplants off at or just below soil level and root maggots may attack young plants. By far the most common problem, however, is cabbage worms and other caterpillars. They feed on foliage as well as the plant parts that gardeners hope to harvest. What they don’t chew holes in they contaminate with their droppings.

Hand picking is one approach to caterpillar control. Appropriately labeled chemical insecticides can also be used. A non-chemical alternative is sprays of Bacillus thuringiensis, a bacterial disease of caterpillars that’s formulated and sold as a pesticide. It needs to be reapplied after rain or overhead irrigation but can be used right up to harvest.

Regular watering during dry weather and a nitrogen sidedressing four to six weeks after transplanting are basic requirements for all the cole crops. Cauliflower must also be blanched to keep the sun from discoloring the developing curd (the white, edible part) and causing off-flavors. Self-blanching varieties have vertical leaves that shade the head; others must have their leaves tied around the heads as soon as the heads become visible.

To promote even development of Brussels sprouts, pinch out the growing tips of the plants after sprouts have formed along the stems. If you don’t, you usually end up with a few large sprouts toward the bottom of the stem and a lot of little ones toward the top. To give sprouts more room to grow, twist off the lower leaves.

Kohlrabi is ready to harvest when the bulbous stems are 1 ¾ to 2 inches in diameter. Some varieties get woody if they grow much larger than that; others are said to maintain eating quality at larger sizes. When in doubt, harvest early.

Broccoli is ready to harvest when the heads have reached maximum size and before they open to form little yellow flowers. Side shoots will form smaller heads -- you can harvest these, too. Cauliflower is ready to harvest when heads are about 6 inches in diameter. In hot weather, heads will reach this size only three or four days after blanching; in cool weather, it will take a week or two. Heads left covered too long, especially in hot weather, will quickly rot.

Harvest Brussels sprouts from the bottom up. They’ll have better flavor if they’re left on the plants until a frost or two has occurred. Cabbage, too, is better if allowed to mature past the first frost, McLellan notes.

Chinese cabbage can be harvested anytime. Young leaves make an excellent salad vegetable or stir-fry ingredient. Mature heads should be harvested when they are fairly solid but before the upper leaves turn yellow.

#lkj#

ANR Communications Contact: L. Johnson or T. Ellis
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 355-8478
East Lansing, MI 48824-1039 5/19/00

PLANT GALLS TAKE MANY FORMS
ON VARIETY OF PLANTS

EAST LANSING, Mich. -- A goldenrod stem that looks as if it’s grown around a marble and tiny, red, clawlike projections on maple leaves don’t at first glance appear to have anything in common.

In fact, they are both plant galls -- abnormal tissue growth that occurs in response to injury by an insect or mite, bacteria, viruses, nematodes, or a chemical or mechanical irritant, explains Tom Ellis, Extension entomologist at Michigan State University.

"Insects and mites are the most common gall formers," Ellis notes.

Galls may form on any part of the plant, from the roots to the stem to the foliage and flowers. Though they may be unattractive, they rarely cause any real damage to the plant. The most notable exceptions are galls caused by some species of plant-parasitic, gall-forming nematodes, which reduce the growth of certain agricultural crops.

"Mostly galls are just interesting," Ellis says,

Oak trees probably take the prize for the greatest variety of galls caused by insects, he says. Probably the most conspicuous is oak apple gall. The gall begins when a small gall wasp lays its egg in the plant tissue along a leaf midrib or in the petiole (leaf stem). When the wasp larva hatches, it feeds on plant tissues and gives off hormones that stimulate abnormal plant growth -- the gall -- which envelops it. The more or less round growth may reach 2 inches in diameter. Other oak galls may be shaped like tiny red thorns; may be bumpy, smooth or flat; or may be round and prickly like a porcupine or puffer fish.

Maple trees also get their share of attention from gall-forming insects. Leaf spindle galls look like skinny red fingers reaching out of the leaf surface. Maple bladder galls resemble red grape seeds on the leaves’ upper surfaces.

Evergreens aren’t immune, either. Another common gall is the Cooley spruce gall, which forms on Colorado blue spruce trees. Galls are caused by a small, aphid-like insect known as the Cooley spruce gall adelgid. It develops inside green galls that form at the swelling tips of new growth. Galls turn from green to brown in July. Though the galls cause little harm and can easily be removed by pruning, they may alarm homeowners.

No one worries about goldenrod, which is subject to stem galls, Ellis observes. In a thick stand of goldenrod, a large percentage may show the bulbous swellings on the stems. Ice anglers have been known to harvest the larvae inside the galls for bait.

"By the time people notice galls, the damage -- such as it is -- has already been done, and there’s no point in trying to control them," Ellis says. "Fortunately, most galls don’t hurt the plants -- they merely mar the perfection of the leaves or, in the case of goldenrod, which most people consider a weed anyway, the stem."

Preventing gall formation would require controlling the adult stage of the insect and so preventing egg laying, he explains. Sprays would have to be timed just right to control the insects before they lay eggs, and the life cycles of all the possible gall formers aren’t known well enough to do that. So applying insecticides to try to intercept the adults would probably be an exercise in futility and an unnecessary addition of chemicals to the environment, not to mention an unnecessary reduction in the family checking account balance, Ellis notes. "The pesticides might also wipe out beneficial insects and so contribute to an outbreak of other pests that can actually damage plants, pests that are usually controlled by natural enemies," Ellis points out.

A person who finds the galls distressing could hand pick and destroy them, he suggests. This would break the insects’ life cycles and reduce the number of individuals that survive to reproduce.

Another alternative is simply to observe and enjoy studying galls.

"Once you start looking for galls, you may be intrigued and amazed by their abundance and the variety of shapes, colors, sizes and textures," he says. "Get your kids interested and you might be contributing to a lifelong interest in insects and their relationships with plants."

#lkj#

ANR Communications Contact: L. Johnson or M. Nielsen
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-7294
East Lansing, MI 48824-1039 5/19/00

SWALLOWTAIL BUTTERFLIES
EASY TO RECOGNIZE

EAST LANSING, Mich. -- Some of Michigan's native butterflies are small and drab and easy to overlook. Not the swallowtails! This family (Papilionidae) is made up of medium to large butterflies, including Michigan's largest, the giant swallowtail.

"Often people who don't know any other butterflies will recognize swallowtails," observes Mogens "Mo" Nielsen, long-time lepidopterist and author of Michigan Butterflies and Skippers, published last year by Michigan State University Extension.

The most common swallowtail is the black swallowtail (Papilio polyxenes asterius), a velvety black butterfly with rows of yellow and blue spots on its wings. The adults visit a variety of wildflowers and garden flowers for nectar. The female lays eggs on plants in the carrot family, particularly Queen Anne's lace. Mature larvae are banded in bright pea-green and black; black areas have yellow spots. The black swallowtail is found in open fields, old farmland, vacant lots and city gardens throughout the Lower Peninsula and in scattered areas in the Upper Peninsula.

The tiger swallowtail (Papilio glaucus) has bright yellow wings with black stripes and black borders with yellow and blue spots. Adults sip nectar from a wide range of wild and domestic flowers. Larvae are a dark celery green with a narrow collar of black and yellow and two false eyespots on the bulging area immediately behind the head. They feed primarily on wild black cherry. Tiger swallowtails are common across the southern half of the Lower Peninsula in brushy fields, rural roadsides, and urban parks and gardens.

The zebra swallowtail (Eurytides marcellus) is somewhat smaller than the tiger. Its greenish white wings have black stripes and longer tails than other swallowtails. Its greenish caterpillar has narrow bands of black and yellow; it feeds on pawpaw, so it's often seen in southern counties where pawpaw grows. This distinctive but uncommon butterfly frequents floodplain forest openings and edges, stream margins and occasionally turns up in rural and urban gardens.

The largest member of the swallowtail family, and the largest butterfly in Michigan, is the giant swallowtail (Papilio cresphontes). It's dark brown with diagonal bands of large yellow spots on its wings, and the largest individuals may be more than 6 inches from wingtip to wingtip. Mature caterpillars are olive brown with blotchy light and dark markings and two white patches, one at the rear end and another toward the head, that make it resemble a large bird dropping. Females prefer prickly ash and hop-tree for egg laying. The giant swallowtail is found near forests and woodlots containing the host plants, and in fields, gardens and roadsides throughout the southern half of the Lower Peninsula.

The spicebush swallowtail (Papilio troilus) is a large black butterfly with bluish green patches on the hindwings and spoon-shaped tails. The undersides of the wings are spotted with orange. Adults take nectar from a wide range of wild and cultivated flowers. Caterpillars, which are bright green with two large black and tan eyespots behind the head, feed on spicebush and sassafras in Michigan. Look for it in or near oak-hickory forest openings and edges, trails and roadsides throughout the southern two-thirds of the Lower Peninsula.

In northern parts of the state, the Canadian tiger swallowtail (Papilio canadensis) visits a wide variety of flowering plants. It looks much like the tiger swallowtail and was long thought to be a subspecies of it. It was recognized as a separate species in 1991, Nielsen notes. It can be found in or near pine barrens, aspen forest openings and edges, and along stream margins and roadsides in the northern half of the Lower Peninsula and through the Upper Peninsula. Trembling aspen is the preferred food for larvae, which look much like tiger swallowtail caterpillars. Adults frequently congregate in large numbers -- 40 or more -- where moisture and nutrients are available from damp soils along trails and streams.

Michigan's "special concern" swallowtail is the pipe-vine swallowtail (Battus philenor), an uncommon, large, black butterfly with iridescent greenish blue on the hindwings of the males. Females are essentially black with white spots near the edges of the wings. The wings flutter rapidly while adults feed on nectar. Larvae are velvety black or dark brown with rows of fleshy red tubercles along the body. They feed on Virginia snakeroot (also listed as a threatened species), Dutchman's pipe and wild ginger. Look for the adults in open fields near oak-hickory woods in the southernmost counties in late April and early May.

"Swallowtails typically are easy to identify," Nielsen says, "but not always. The spicebush swallowtail looks a lot like the pipe-vine swallowtail, which is distasteful to birds, so the similarity is probably not an accident. A bird that tries to eat a pipe-vine swallowtail tends to avoid butterflies that look like it, so you have the spicebush swallowtail, a dark form of the female tiger swallowtail and the black swallowtail mimicking its appearance."

Where the ranges of the tiger swallowtail and the Canadian tiger overlap, these two are easy to confuse, also, he notes.

By and large, however, members of the swallowtail family are among the easiest butterflies to get to know and recognize. They are a good introduction to the world of butterflies, in which Nielsen has spent so much time.

Michigan Butterflies and Skippers is available for $19.95 from the Michigan State University Bulletin Office, 10B Agriculture Hall, East Lansing, MI 48824-1039. Its 248 pages are filled with gorgeous color photos and information on the distribution, habitat, stages and habits of the 159 butterfly and skipper species that have been recorded in Michigan. It's one of a number of nature guides published by MSU Extension.

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

WANT MORE SHADE?
PLAN TO PLANT A TREE

EAST LANSING, Mich. -- The best time to plant a shade tree in your yard was 30 years ago. If you missed that window of opportunity, the next best time is this year.

Summer is a good time to plan tree planting because it’s the time you most appreciate the shade that trees provide, suggests Mary McLellan, Master Gardener program coordinator at Michigan State University.

"You don’t want just any tree, however," she points out. "You want a tree that’s hardy in Michigan, well adapted to the growing conditions in your yard, and relatively free of undesirable characteristics, such as pest problems."

"Hardy" means a plant will survive and thrive in Michigan’s climate. Native species and cultivars developed in other northern areas are usually your best bet.

"Adapted" refers to the soil type, moisture, sunlight, drainage and other aspects of the planting site. A good match between the conditions in your yard and the conditions a plant needs greatly increases your chances of success in growing it, McLellan sums up.

"A pine transplanted from a sandy spot in northern Michigan to a heavy clay soil in the south will be lucky to survive at all," she notes. "Likewise, an upland hardwood such as a hickory, walnut or beech would struggle in a low-lying, moist spot."

A bad match between growing conditions and plant needs may kill the plant or stress it so much that it can’t resist attack by insects or diseases, which finish it off.

Among trees that should thrive in your yard, you will have a range of choices in size, shape, susceptibility to pests and storm damage, the presence of flowers and fruits, leaf color, fall color and other traits. If you figure out what traits you want in a tree, you can then look for a tree that provides those traits and doesn’t have a host of problems that will require extra maintenance or perhaps shorten the life of the tree in the landscape.

"If you want a trouble-free tree, you probably want to avoid willow, silver maple and Siberian elm, which are prone to damage from wind and ice storms," she notes. "Siberian elm is also prone to defoliation by elm leaf beetles. European white birch usually falls victim to bronze birch borers and leaf miners. Some trees that would otherwise be desirable in the landscape are avoided because of messy fruits -- black walnut and mulberry are prime examples." Mature size is another consideration. If your house and yard are small, a tree that will grow to 100 feet high will eventually grow out of proportion to its setting.

"Space to grow is often overlooked when people plant trees," McLellan observes. "After all, the plants are relatively small now. But a lot of problems can be avoided by planting a tree that will reach 40 feet in height and 30 feet in diameter in a space that gives it room to reach that size. Planting it underneath utility wires or within 10 feet of the side of a two-story house is going to create maintenance problems down the road."

#lkj#

ANR Communications Contact: L. Johnson or M. McLellan
MICHIGAN STATE UNIVERSITY Telephone: 517-432-1555 or 353-3774
East Lansing, MI 48824-1039 5/19/00

WILDFLOWERS DO BEST
IN WELL PREPARED SITE

EAST LANSING, Mich. -- It’s true that wildflowers in the wild manage to grow without assistance from human gardeners. Gardeners trying to establish a wildflower meadow, however, will get better results if they pick a suitable site and prepare it properly.

Mary McLellan, Master Gardener program coordinator at Michigan State University, says most meadow wildflowers will grow best on a well drained site with at least several inches of topsoil. On a dry site with no topsoil or a poorly drained clay, wildflowers will have just as much trouble growing as vegetables would, she says.

A key part of site preparation is eliminating perennial weeds such as quackgrass, McLellan advises.

"It’s a good idea to start preparing the site a year ahead," she suggests. "Repeated tilling will eventually remove competitive perennial grasses and other vegetation. It will also bring seeds of annual weeds to the surface where they can germinate. Then the next tilling kills them."

People often opt for a combination approach: an application of a broad-spectrum herbicide such as Roundup to get rid of the perennials and tilling to control germinating annuals.

"However you choose to do it, eliminating quackgrass and other perennials is a must if your wildflower planting is going to succeed," McLellan says.

Another important step is selecting plants native to the Great Lakes states. They are best because they’re adapted to local growing conditions. This is especially important in perennials, which must survive over the winter. Plants from more southerly parts of the United States may not. Easy-to-grow perennials for beginners include black-eyed Susan, coreopsis, gray coneflowers (on good soil, they will grow to a height of 6 feet), joe-pye weed, butterfly weed, purple coneflower, bergamot (a great butterfly plant), New England asters (purple) and goldenrod.

Perennials can be slow to get established, and many don’t bloom the first year. Most mixtures of wildflower seeds contain some annuals for quick cover and color the first year and perennials for the long haul, McLellan observes. Some of the annuals may reseed themselves. Even if they don’t, they’ll take up space that first year that would otherwise be available for weeds.

Early spring -- as soon as the soil is dry enough to work without clumping -- is the best time to sow a mixture of annuals and perennials, McLellan says. Perennials can also be seeded in the fall.

Before seeding, the soil should be worked lightly with a garden rake, lawn thatcher or rototiller. Distribute seed with a hand-cranked whirlwind seeder, if possible, and strive to spread the seed evenly.

A wildflower meadow tends to have clumps of species rather than a homogeneous mixture, so some gardeners will buy seed or transplants of specific varieties to plant together in clumps or drifts. Blending the edges of these colonies blurs their boundaries and adds to the natural look.

How much seed do you need? For a 750-square-foot area, 1 to 2½ ounces of perennial seed, ½ to 1 ounce of native grasses and ½ to 1 ounce of annual wildflower seed. Mixtures usually have filler material to make them easier to spread evenly, so labels will call for larger quantities for a given area, McLellan notes.

After sowing, firm the soil bed with the back of a garden rake or, for a larger planting, with a lawn roller.

Watering is not necessary, though it will speed germination and establishment. If you decide to start watering, it’s a good idea to continue during dry weather throughout the first growing season, McLellan suggests.

The big chore during the first year is weed control. Weeds must generally be hand pulled as soon as they’re big enough to be distinguished from the flowers.

Once a wildflower meadow is established, annual maintenance consists of mowing to a height of 4 to 6 inches in late October or early spring, and burning the site every three years in March or early April.

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