   Spring Flowering Bulbs - September 6, 2000 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Spring flowering bulbs bring early color to beds and perennial borders. Many bulbs require little attention after planting and will bloom year after year. In addition, there are hundreds of species and varieties in a broad range of shapes and sizes. The classic choices include tulips, hyacinth, crocus, daffodils, and narcissus. Some lesser-known spring flowering bulbs are Dutch iris, scilla, and allium. In this column, the word "bulb" will include corms, rhizomes, tubers, and tuberous roots. In practicality, these are underground food storage structures that allow the plant to survive periods of unsuitable weather. Hardy spring flowering bulbs should be planted in late summer or early fall (September and October) and bloom between January and May. Fall gardening catalogs are marketing them right now. Before purchasing, consider time of bloom, color, and mature height to create a pleasing design (see last week's column on perennial border design). Also buy only high quality bulbs, especially those varieties that produce the showiest flowers. This is important because the flower that will bloom next spring has already formed inside the bulb. Poor quality bulbs will produce poor quality flowers. If you buy bulbs early, store them in a cool (below 70 degrees F), dry place and preferably in peat moss or vermiculite. Most bulbs need full sun. Five to six hours of full sun is a minimum. Bulbs left in the ground year after year will do better with eight to ten hours of sun. Plantings on south and west exposures will bloom earlier than those on north and east exposures. Soils must be well-drained and preferably dry and friable at planting time. Spade the soil 10 to 12 inches deep adding compost liberally as you work. Dried leaves, grass clippings, or other organic matter could be substituted as these materials will break down further over time prior to the bloom period. Add one pound 5-10-10 fertilizer per 50 square feet of bed. This can be placed in a layer two or so inches below the bulbs or mixed with the soil. Do not allow a bulb to be in direct contact with concentrated areas of fertilizer, as it will damage the bulb. Planting depth can vary with local conditions. In general, bulbs should be planted two to three times the diameter of the bulb. Reputable local nurseries and successful growers may provide you with some hints on specific species and varieties. After planting, mulch the soil with at least two inches of organic matter (leaves, grass clippings, or straw). Normal rainfall (whatever that is) usually provides enough irrigation water for successful flowering. If we have a dry winter, then irrigation may be necessary. The trick for successful flowering year after year is to promote sufficient foliage growth to store enough energy in the bulb to produce flowers the following year. So, here again, irrigation in the spring may also be necessary, especially if the spring of 2000 is anything like the spring of 1999 (dry, dry, dry). After flowering, remove flowers before they produce seeds. Seed production saps energy from the plant. This energy is much better used to produce the following year's flowers. A light application of 5-10-10 fertilizer after blooming will improve the following year's blooms. Fertilizer should be kept off the leaves to prevent foliar damage. Spring flowering bulbs can usually be left to themselves for many years. However, over time, they may become too crowded. Digging and dividing should only be done after flowering and growth have ceased and the foliage has dried. You can share the extras with neighbors and friends. Finally, remember that javelina love tulips and are curious about many other bulbs. Narcissus, daffodils, and bearded iris are best used in unprotected/unfenced areas. The University of Arizona Cooperative Extension has publications and information on horticulture and plant science. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@kachina.net and be sure to include your address and phone number. The Yavapai County Cooperative Extension web site is http://ag.arizona.edu/yavapai/. |