Good hardy bulbs contain all the ingredients to bloom and the year after planting and will do so if they are planted in a well drained area and are not damaged by animals.

A proposed bulb site should have well drained soil. If the area remains puddled or soggy several hours after a normal rain, it is probably poorly drained. In wet soil, bulb roots may stop growing and rot.

The site should also receive at least six hours of full or partial sun each day. Less sun will keep the bulb from making adequate food to support next year's bloom. A few bulbs prefer a shady site, such as tuberous begonia and caladium. Deciduous trees do not normally create enough shade in May and June to interfere with food production of spring-flowering bulbs.

Bulbs will tolerate most types of soil, although one rich in organic matter is preferred. Improve organic content by adding well composted manure, leaf mold, peat moss or compost; add fertilizer as described in the next section, and work the soil to a depth of 10 inches before planting.

PLANTING

When setting bulbs out, be careful to plant at correct depth below the soil surface, measured from the top of the bulb. Generally, the larger the bulb, the deeper it is planted. Hardy bulbs are set deep to survive winter's cold - usually at a depth 2 1/2 times under their size - but most tender bulbs are planted close to the soil surface. Consult the planting guide for specific depths. Plant a little deeper in very sandy soil, and a little shallower in heavy soil.

A handy trowel is commonly used to spotplace one bulb at a time, but stainless steel tubular bulb planters are also popular. Bulb planters usually have depth measurements etched in the surface to help ensure proper planting depth. This tool comes as a hand planter or on a long handle, an excellent idea for large gardens or for gardeners with back problems.

Push the planter into the soil to the proper level. Then scoop the soil out of the hole, using wrist action. Drop the bulb, in basal plate down, and replace the soil. After planting, water to encourage root development.

TIMING

Most hardy bulbs may be purchased only in autumn, but lilies and some alliums are also available in spring. Some catalogs now offer prechilled bulbs that may be planted in spring and will bloom immediately. All hardy bulbs should be planted as soon as possible after they are obtained. For best results, bulbs should be in the ground by mid-October. Some, such as tulip, may be successfully planted until the soil freezes. There is no harm in planting early, even is some growth occurs. Rarely, a new bulb will produce leaves in fall but not flowers.
 
 

Existing clumps of bulbs may be moved any time after the leaves have died back and bulbs are fully dormant. Note that some bulbs, such as trillium and fritillaria, do not transplant well. Summer flowering bulbs are available for purchase in late winter through late summer, depending on the plant. Some, like tuberous begonias, are started indoors. No tender bulb should be planted outdoors until the soil has warmed to 65° F average temperature and danger of frost is past. Consult the frost map in this bulletin for dates for your area.

FERTILIZING

Flowering the second or third year after planting is influenced by previous and continuing care. To thrive, bulbs must be able to "fill out", to replace food reserves used in growth and flowering each year.

At planting time, mix in a slow-release fertilizer high in phosphates, such as bone meal (1-11-0), superphosphate (0-20-0) or a complete commercial bulb fertilizer such as 5-10-5 or 12-12-12, at the rate of 2 pounds/100 square feet. Bone meal is recommended at 5 to 6 pounds per 100 square feet to 1 ounce (2 tablespoons) per square foot. New research indicates that nitrogen is much more important to bulbs than previously thought.

Although it's not essential, some gardeners like to fertilize hardy bulbs again in spring to give the roots a quick burst of energy and success for subsequent seasons. Use a complete fertilizer such as 5-10-5 or 12-12-12 at the rate of 2 pounds (4 1/2) cups per 100 square feet. Rake it in lightly and water. Fertilize tender bulbs in this manner, two or three times during the growing season.

Next fall, add bone meal, bulb fertilizer or superphosphate again to hardy bulbs and lightly turn it under with a hand trowel. Be careful not to disturb shallow bulbs.

POSTBLOOM AND WINTER CARE

Proper postbloom care helps ensure good flowering next season by allowing the plant to put its energy into filling bulbs. Developing seeds compete with growing bulbs for food, so cut of the flower stalks as close to the leaves or ground as possible. Do not cut leaves back until they are completely yellow, however. As long as leaves are green, they continue to feed the bulb.

Planting and fertilizing are the major chores for fall, but you may also wish to place 2 to 3 inches of mulch above the bulbs to help insulate the soil. Alternate freezing and thawing cycles may cause soil heaving which disturbs roots and can expose bulbs to killing cold temperature. Gently rake back heavy mulches such as oak leaves in early spring or shoots begin to emerge. Straw, peat moss, compost and other light mulches may be left in place and will add organic matter to the bed as they decompose.