Blooming of the Forsythia

Flowers

• Forsythia flowers are bright yellow, about an inch and a half long, with four petals that are fused together at the base of the flower. The flowers are gathered in clusters of two to six blooms each, and the clusters are distributed along the branches that grew during the previous season, so a well-pruned, healthy shrub is usually covered profusely with the showy flowers.

Bloom Time

• Forsythia is one of the earliest to bloom of all shrubs, unveiling its flowers at the very beginning of spring. The shrub blooms before its leaves, and indeed the leaves of most other garden plants, appear, so the forsythia flowers are prized by gardeners for their early introduction of color into an otherwise drab garden. Forsythia's bloom time is prolonged, too; the flowers persist for at least a week and sometimes as long as three weeks.

Pruning

• Forsythia blooms on the previous year's growth, so proper pruning is essential for optimal flower production. Ideally, you should prune the shrub immediately after it finishes blooming in the spring so that it has plenty of time to produce new growth for next year's blooms. Pruning later in the season will remove new growth and reduce the number of subsequent flowers. Removing up to a third of the old growth each spring will help the shrub to grow and bloom vigorously.

Hardiness

• Although the forsythia shrub itself is generally able to withstand temperatures as low as -25 degrees Fahrenheit, its flower buds are considerably less hardy and will often die if winter temperatures fall below -5 degrees or if there is a late-season freeze. Open flowers that are damaged by cold wilt and turn brown. Growers have developed some cultivars whose flower buds can tolerate winter temperatures as low as -20 degrees; these cold-hardy varieties include "Sunrise" ( Forsythia x intermedia "Sunrise" )and "Happy Centennial" (Forsythia x "Happy Centennial") . "Northern Sun" (Forsythia x "Northern Sun") and "Meadowlark" (Forsythia x "Meadowlark") are even hardier; their flower buds are able to survive temperatures of -30 and -35 degrees, respectively.