Michigan State University Extension
Ornamental Plants plus Version 2.0 - 00000487
01/01/98
Height: 6 ft Spacing: 2 ft Type: tender bulb Flowers: Orange, pink, purple, red, white, yellow
Comments: The many types of Dahlia like a fertile, well- drained soil with a constant supply of moisture. Mulch the bed and avoid giving the plants high nitrogen. On poor sites the plants are leggy. Best growth occurs in full sun but the plants tolerate partial shade. Do not plant Dahlias until the soil has warmed up as the roots rot in cold wet soil. Tall varieties may need a support stake installed at planting time. Removal of side buds gives larger flowers and removing the old flowers as they fade promotes increased blooming. Dwarf cultivars are planted 12 to 18 inches apart. Most Dahlias are planted 6 to 10 inches deep. Frosted plants are cut off 4 to 6 inches above ground level. Dig the roots and allow them to dry. Cover them with sand or peat and store them at 50 degrees.
Propagation: Dahlias are propagated by division or cuttings. For cuttings, use new shoots and make cuttings 3 to 4 inches long. Remove the basal leaves and insert the cuttings in sand, perlite or vermiculite. The root clumps are divided in the spring. Each division needs part of the old stem on it.