University of Vermont Extension
Department of Plant and Soil Science


Bulbs for Spring Bloom                    OH 21

After a long, dreary winter, and during the even worse "mud" season, hardy spring bulbs can be used to provide bright
and cheery color in the landscape. Late August through October is the best time to buy and plant these bulbs.

Hardy bulbs exceed all other groups of plants in producing color in the spring garden. They are usually the earliest
plants to bloom, and most of them have exceptionally showy flowers. Snowdrops and winter aconite are the first to
show up in the spring, usually in March. These are soon followed by crocus, scilla, and chionodoxa. Then come the
hyacinths, daffodils, and tulips.

Bulbs are attractive when placed along paths and walks, planted around pools, or placed in front of foundation
plantings around the home. Except for tulips and hyacinths, most spring bulbs may also be effectively naturalized
(scattered randomly throughout the landscape).

Most bulbs do well the first year, regardless of where they are planted, but very few do well for several years unless
they have a fair amount of light and generally favorable growing conditions. Planting bulbs beneath large trees is seldom
satisfactory because of the dense shade cast by the trees and the competition with tree roots, but scilla, crocus, winter
aconite, and snowdrops will perform well under trees.

Hardy spring bulbs also need soil with good drainage where there is no danger of water standing on the surface of the
ground through winter or spring.

Soil preparation: To keep the bulbs in vigorous condition and performing well for several years, prepare the soil well
before planting. Fertilizer added at planting will help maintain vigorous growth and large flowers over the years. The
best fertilizer is a complete commercial one, such as 5-10-5 or 6-12-6 grade, applied at the rate of 3 pounds per 100
square feet or surface area. Work it thoroughly into the top 8 inches of soil. Bone meal is a good organic fertilizer.

Organic matter can be added to "heavy" clay soils to improve their physical structure. Manure must be well rotted,
because fresh manure may injure the bulbs. Apply organic matter at the rate of 5 bushels per 100 square feet, and
work into the top 8 inches of soil.

Planting: In light, sandy soils, bulbs may be planted by the dibble method: Make a small hole in the soil with a short,
pointed stick; place the bulb in the soil; and after pressing the bulb down into the soil as far as possible, cover it with
soil. In soils that are rather heavy, it is much better to use a trowel to dig the hole for each bulb. Prepare rather loose
soil underneath the bulb so that roots can easily penetrate the soil.

Depth of planting: Plant tulips and narcissi with the tops of the bulbs 4 inches below the surface of the soil. In light,
sandy soils, plant tulips deeper than in heavy soils. Plant smaller bulbs, such as scilla, chionodoxas, grape hyacinths,
and snowdrops, with their tops about 2 inches below the surface of the soil.

Spacing: Plant larger bulbs, such as tulips and daffodils, about 8 inches apart; crocus and grape hyacinths about 4
inches apart; and smaller bulbs, such as winter aconite and scilla, 2 to 3 inches apart. For a naturalized planting,
narcissi may be placed 10 inches apart and small bulbs about 20 to the square foot.

Rodents: If rodents are a problem, it may be necessary to cover the beds with fine mesh wire to prevent mice from
digging out the bulbs. A small handful of certain repellent materials may be placed around the bulb at the time it is
planted. These materials are available from your local lawn and garden dealer. Read the label on the containers of
repellent before using, and follow any precautions.

Spring care: Certain practices in the spring after bloom will affect the growth and development of bulbs for the next
few years. Remove seed pods. (When they are left on, new bulbs of tulips and narcissi are much smaller than when the
pods are removed.)

Removing the leaves has just the opposite effect, however. After bloom, leaves are needed to produce the food that
will go into making the bulb and bloom for the following year. A handful of fertilizer sprinkled around the bulbs after
the bloom will help this process.

Let the leaves remain on the spring-flowering bulbs until they show signs of ripening and turning yellow. In Vermont,
this time is usually mid-June for tulips and mid-July for narcissi. Other types of bulbs vary greatly in the date at which
they are mature. This ripening process may be hastened by folding over the leaves and putting rubber bands around
them.

Tulip fire: During extended wet weather in the spring, the fungus "Botrytis" (tulip fire) may cause leaf tips of tulips to
decay. Cut off and burn all decayed leaf tips as soon as you notice them. Infected buds and foliage showing grayish tan
spots should also be eliminated. Removing infected foliage is the most important way to control this disease, although
certain fungicides can also be used to help control it. (See GD 32, "Botrytis.")

Digging: Clumps of hardy bulbs should be dug and divided every 3 years or flower quality and size will deteriorate.

Allow bulbs to mature as long as possible before digging and dividing. Digging too soon after bloom will keep the
bulbs from flowering the following year, although they will flower in the second year. Very small bulbs, especially
bulblets separated form large bulbs, may not flower simply because they need a few years to mature. On the other
hand, don't wait until the foliage disappears or you won't be able to find the bulbs.

When the foliage turns yellow (usually late June to mid-July), lift the bulbs carefully, free them from soil, remove the
tops, pull them apart, and replant immediately. If not replanted at once, they may be washed, spread in an airy and
shady place to dry, and then stored in shallow boxes in a cool, dry, airy place until planting time the following fall.


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Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. Lawrence Forcier, Director, UVM Extension System, Burlington, Vermont. University of Vermont Extension System and U.S. Department of Agriculture cooperating, offer education and employment to everyone, without regard to race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status.

Last reviewed 2003