Fall Bulbs for Spring Color

Among the first plants to bloom in Spring are those that arise from bulbs or similar subterranean storage organs. Crocus, hyacinths, tulips, daffodils and irises are among the best known but there are many others. The brightly colored flowers bring a cheery preview of spring and are a much welcome site by the end of winter. There are a variety of plants that will bloom much earlier than tulips and daffodils. Beginning in mid to late February, scilla and eranthus will begin to bloom. Plant a variety of bulbs to provide steady color from late winter through spring and summer.

The term ‘bulb’ is applied loosely by gardeners to any underground fleshy organ in which a plant stores starches and other nutrients to carry it through its dormant period—usually winter. The storage tissue may comprise modified leaves, stems or roots. A true bulb comprises an entire plant in a very compact form with very thick leaves for protection and storage. The stem section between leaves (internode) is extremely short. More accurate terms for storage organs include—bulb scale (modified leaf on the margin of a bulb, e.g. lily); corm (modified stem, e.g. gladiolus), rhizome (modified stem, e.g. iris), tuber (modified stem e.g. potato) and storage roots (enlarged root segments, e.g. yam, cassava, and carrot).

For microorganisms, bulbs are a concentrated source of starch and proteins. The gardener can minimize the likelihood of infection by soilborne fungi and bacteria by planting bulbs in a very well drained soil with a high content of sand and organic matter. Bulbs do not require a large quantity of fertilizer, although a low rate of a slow release fertilizer, such as Osmocote or bone meal, may be mixed into the soil at the time of planting. Do not fertilize the growing plant while it is flowering. Once flowering has ceased, a supplemental feeding with a fertilizer that is relatively low in nitrogen will ensure the continuation of robust flowers the following year. Bone meal or a fertilizer with an analysis of approximately 5% nitrogen, 10 % phosphorus and 5% potash (5-10-5) is ideal. Too much nitrogen promotes heavy leaf growth and may retard flowering.

Naturalizing:
Many bulbs are hardy in the Midwest and do not have to be recovered from the soil before the ground freezes. In fact, it is the cold of winter that prepares the bulb to flower in the spring. Because bulbs can be planted and maintained with very little care, they are ideal for naturalizing—that means placing them in a landscape where they will look so natural that one would believe they were natives.

Any landscape can benefit from naturalized bulbs, from rock gardens and xeriscapes to grasslands and woodlands. Most bulbs will thrive in full sun, although crocus, daffodils and hyacinths will flower in partial shade, as will several others. Marginal areas near prominent features, property lines or changes in the landscape are ideal for placing bulbs for naturalization. Remember, not all bulbs will naturalize everywhere, and all bulbs require a well-drained soil to prevent rotting.

To achieve a truly natural look, plant your bulbs in random groupings. If the plants appear too orderly the natural look is lost. The great benefit of naturalizing bulbs is that they require very little maintenance. Provide a low nitrogen (less than 10%) slow release fertilizer in the fall and divide as frequently (or infrequently) as you desire.

Quick Tip:
When planting bulbs for naturalizing, use a spade to pry a slit in the soil or sod. Drop the bulb in and press the soil back in place with your foot. This works especially well for small bulbs such as crocus and Muscari (Grape Hyacinth).

Choose from among the plants listed below for naturalizing in your landscape. The suggestions are based on recommendations made by Langeveld—producers of the finest Holland bulbs.

Spring bulbs may be planted anytime in autumn until the ground is no longer workable in winter. Recommended planting depths vary depending on plant species. The following guidelines are provided by Langeveld—the producers of the finest Holland bulbs.

Forcing Bulbs:
The term forcing is applied to the process of tricking a plant to bloom out of season, and it is an incredibly easy task with bulbs. Most bulbs prepare to flower after they are exposed to cold temperature for a specific minimum amount of time. In most cases, 13 to 15 weeks of chilling is sufficient to initiate flower formation. This cooling requirement is natures way of ensuring that plants remain dormant through the harshest part of winter and that, once they break dormancy, they all flower at the same time so that flowers reliably can be cross pollinated.

To force bulbs, choose healthy, large firm bulbs. Tulips, Hyacinths and Daffodils are forced most often. Wrap bulbs in a paper bag to prevent desiccation and place them in a refrigerator or other location that will remain between 35 and 50 degrees. After 13 to 18 weeks, remove the bulbs from the refrigerator. The longer bulbs are chilled, the longer will be the flower stems. Plant bulbs with the top approximately one-half inch below the soil. Plant bulbs in a loose medium that will drain quickly. Good drainage is essential to prevent bulbs from rotting. Warm temperatures will bring the plant out of dormancy. The warmer the temperature the faster the flowers will mature. After forcing, bulbs may be planted in the garden, however, it will take several years before they rebloom.

Bulbs may be forced in special narrow necked vases without soil. Decorative stones or marbles may be placed in the vase if desired. Place the chilled bulb in the mouth of the vase then fill it just to the point that the water touches the bottom of the bulb. Add water as needed but never bring the water level higher than the bottom of the bulb. Roots will grow down into the vase and a flower spike will emerge in a few days.