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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Selecting and Planting Spring-Flowering Bulbs

This article was published originally on 9/17/1999

As the garden season winds down for the year, now is a great time to select and plant a few spring-flowering bulbs for next year. Spring-flowering bulbs offer reliable color and fragrance to the garden before many other plants wake from their long winter's nap. Gardeners can choose from traditional spring-flowering bulbs, such daffodils, tulips, and hyacinths, or the unusual like squill, crown imperial, giant onion, or guinea-hen. A small investment of time and money this fall will reward you with beautiful flowers next spring.

Selecting Bulbs

After deciding which types of flowers you want in the spring, select only firm, solid bulbs for planting. Avoid bulbs that are shriveled or lightweight. Bulbs that are discolored by mold or that contain soft spots should also be avoided.

Size matters when selecting bulbs. The bigger the bulb the better the flower display. Smaller bulbs often bloom but you get more bang for your buck with the larger bulbs.

Planting Bulbs

October is a great time to plant spring-flowering bulbs. The soil temperatures in early fall are ideal for good root development. However, some bulbs like tulips may emerge in the fall if they are planted in September before the soil temperatures begin to cool. Procrastinators can plant spring-flowering bulbs as late as December if the ground remains unfrozen.

Select the planting site as carefully as you selected the bulbs. The soil should be fertile and well drained. Bulbs planted in wet sites will often be short-lived. Amending poor soils will go a long way in ensuring dependable blooms for the spring and every spring thereafter. The more suitable the site, the longer the bulbs will last in the garden.

Most bulbs prefer a sunny site as well. Bulbs are often successful beneath a high branched deciduous tree because they usually flower before the tree fully leafs out. After the bulbs have finished flowering, many can tolerate the light shade from trees.

Bulbs are generally planted along the foundations of homes or in beds or borders for unobstructed views of the blooms. Consider planting them with ornamental grasses and other perennials that will hide the foliage as it yellows. Plant bulbs in large groups for maximum visual impact. Bulbs planted alone or in rows like soldiers are not nearly as effective as large sweeps or drifts of color. For a naturalized look, simply toss handfuls of bulbs in the garden and plant them where they land. The smaller bulbs should be planted in large groups (20 or more) or elevated in a berm or rock garden so they can be seen easily. Bulbs with different bloom times can be mixed together for a long-lasting display.

Proper bulb depth is another important planting requirement. The general rule is to plant the bulb at the depth of 2 1/2 to 3 times the height of the bulb. Tulips, daffodils, and hyacinths are often planted 6-8 inches deep. The smaller bulbs like squill, snowdrops, and crocus are often planted 3 to 4 inches deep. Larger bulbs can be spaced 4-6 inches apart while a 2-3 inch spacing is more suitable for the smaller bulbs.

Don't forget to plant your bulbs right side up. This means planting the pointed end up for bulbs like tulips, daffodils, hyacinths, squill and many others. For some of the more unusual bulbs or bulb-like structures it can be harder to tell which end goes up. If no roots or buds are apparent, you can plant some bulbs on their sides. The bulb will find the sun and bloom normally with only a little extra effort.

There are a number of tools made for planting bulbs. Bulb planters, trowels and auger attachments for electric drills are available to assist the gardener in bulb planting. For a mass plantings of bulbs in an area, remove the soil to the proper depth with a shovel. Place the bulbs in the desired arrangement or pattern and then carefully backfill with soil.

Fertilizers like 5-10-5, Bulb Booster, or Bone Meal can be incorporated into the soil at the time of planting. Bone meal is often slower acting and more expensive than the others. These fertilizers are more important for the development of next year's bulb than they are for the upcoming flowers of this year's bulb.

After planting be sure to water the area thoroughly to provide plenty of moisture for root growth. The addition of a light blanket of mulch on top of the soil will moderate soil temperatures. This will allow the bulbs a little more time for root growth before the ground freezes. The mulch layer will also conserve moisture in the soil the following summer.

Many garden centers and garden catalogs offer a wide variety of spring-blooming bulbs for sale. With a little planning and effort this fall you can be enjoying their cheery blossoms next spring.



This article originally appeared in the September 17, 1999 issue, p. 119.

Year of Publication: 
1999
Issue: 
IC-481(23) -- September 17, 1999