Iowans have been enjoying the beauty of tulips, daffodils, and other spring- flowering bulbs for the past few weeks. Proper care through the remainder of the spring will help to insure repeat performances in succeeding years.
Remove the flower heads on tulips and daffodils as soon as the flowers fade. This prevents undesirable seed and pod development which could reduce flower production in following years. Additionally, 2 to 3 pounds of a 5-10-5 or 6-10-4 fertilizer may be applied to 100 square feet of bed area immediately after blooming. Wash off any fertilizer which may remain on the foliage to prevent it from burning the leaves. Control weeds which compete with the bulb plants for water and nutrients. Hand weeding is often most practical.
The foliage of the spring-flowering bulbs should not be removed until it has died and turned brown. The length of time it takes the foliage to mature depends on plant type, weather, and cultural maintenance. It may not be until late June for some bulb types. Premature removal of plant foliage stops bulb growth and may drastically cut flower numbers next spring.
This article originally appeared in the May 6, 1992 issue, p. 71.