I believe garden flowers are most appreciated and enjoyed in early spring. They are a refreshing change from the drab browns of winter. Unfortunately, we have to plan and plant for this beauty several months before we actually see the end result. Fall is the time of year to plant spring-flowering bulbs for that early splash of color in your garden and landscape.
Although most gardeners think of tulips, daffodils, and hyacinths whenever the term "bulbs" is mentioned, there is a large selection of spring-flowering bulbs that can be grown successfully in Iowa gardens. You may want to plant something different this fall, such as the small-growing snowdrops, scilla, glory-of-the- snow, and grape hyacinths, or the tall-growing crown imperial (fritillaria), and giant onion (allium).
Bulbs require little space in the garden and can be planted in annual or perennial flower beds, among shrubs, under trees, and in practically every area of the landscape. The primary considerations for site selection are full sun or partial shade and good soil drainage.
There are certain "rules" to follow to achieve the most impact from the bulbs. Avoid small numbers of bulbs planted individually or in straight rows. Plant blocks of no less than five to ten bulbs of the same species and color. Mass plantings of only one or two colors five or more bulbs, spaced 4 to 6 inches part, rather than individual bulbs spaced several feet apart throughout the area. The short-growing bulbs, such as scilla, crocus, and grape hyacinths, should be planted in drifts of 25 to 50 bulbs for the greatest impact.
Be choosy when purchasing your bulbs. Select, large, firm, plump bulbs or corms. Do not purchase any that are bruised, blemished, or soft. Remember, if they look unhealthy at planting time, they are not going to improve once they are planted.
Plant the bulbs as soon as possible after you purchase them. Although tulips and daffodils have a dry protective covering (tunic) over the bulbs that will allow them to be stored for several weeks, you never now how soon winter will arrive in Iowa and you may be caught with several dozen bulbs in the house and several inches of snow on the ground. Also, some bulbs like snowdrops, fritillaria, and lilies deteriorate rapidly in storage and should be planted as soon as possible. Generally, the best time to plant spring-flowering bulbs is September and October. However, if weather permits most spring-flowering bulbs can be planted as late as early December.
Fertilize the flower bed prior to planting. Inorganic fertilizers, such as a 5-10-5, at the rate of 2 to 3 pounds per 100 square feet can be worked thoroughly and deeply into the soil before planting. A good organic fertilizer for bulbs is bonemeal with its high phosphorus content. Apple 3 to 4 pounds of bonemeal per 100 square feet of area. If planting clumps of bulbs, work 1 tablespoon of bonemeal into the bottom of the planting hole.
The planting depth and plant spacing varies with the species. Generally, plant to a depth that is 2 1/2 to 3 times the bulb's largest diameter.
This article originally appeared in the August 26, 1992 issue, pp. 143-4.