Bulbs can add color to the garden from February until June. Most gardeners are familiar with the famous spring bulbs such as tulips, daffodils and hyacinth, but there are many more. Early flowering spring bulbs such as snowdrop, winter aconite, crocus, glory-of-the-snow, netted iris, and common grape hyacinth give us the first signal of spring.
Common snowdrops, Galanthus nivalis, is the first bulb to up, emerging in January or February. Growing only to 4 to 6 inches tall, it makes a nice edging plant in full sun to shady areas. Snowdrops have snow white hanging bell-shaped flowers.
Winter aconite, Eranthis hyemalis, blooms shortly after snowdrops. This rapidly spreading bulb has yellow flowers which are supported on 3 to 6 inch stems. Once planted, the bulbs should not be disturbed. Winter aconites are attractive interplanted in groundcover and also combine well with crocus. Before planting soak tubers overnight to increase growth rate.
Crocus, Crocus chrysanthus or Crocus vernus, is perhaps one of the most popular small bulbs. Crocus look great naturalized in grassy areas or planted at the front of a flower bed. Many varieties are available offering a large color selection including yellow, white, violet/ white striped.
Glory of the Snow, Chionodoxa luciliae, bloom before the leaves fully develop, allowing eyes to focus on the flower. Use in low groundcover, as a border or in a rock garden. While the majority of the bulbs available are blue with splashes of white, there are also pink and white forms. Glory of the Snow blooms March to April.
Netted Iris, Iris reticulate, grows best in a full sun location. This early spring bloomer grows 3 to 9 inches tall. Violet purple, blue or white fragrant flowers appear in very early spring.
Grape hyacinth, Muscari sp., is a great accent plant that combines well with other spring flowering perennials and bulbs. Blue or white flower clusters resemble a bunch of grapes. Grape hyacinths, if planted in large masses, make a beautiful blue blanket of color.
Selecting a good quality bulb for planting is important. Bulbs should be firm and have a protective papery skin. They should be free from soft or rotting spots, cuts, mold or other signs of disease. Generally, the larger the bulb, the bigger the flower.
While early October is the best time to plant spring bulbs, planting can occur until the soil freezes. Select a location that has a rich, well-drained soil.
The general rule of thumb for planting spring bulbs is to plant two to three times as deep as the bulb is tall. Planting depth is measured form the bottom of the bulb. This means most large bulbs such as tulips or daffodils will be planted 6 to 8 inches deep, while smaller bulbs will be planted about 3 to 4 inches deep.
Bulbs may be incorporated in the landscape almost anywhere except under evergreens, such as pine trees, or other dense shade areas. Sunlight is needed to trigger proper growth in the spring. Light is also needed for the period after flowering when the foliage manufactures food to be stored in the bulb for the following year’s growth cycle. A good rule of thumb is to plant bulbs of one variety or color in a mass, this will have greater visual impact. The more bulbs planted together of one variety and color, the greater the impact.
For more information on bulb basics and descriptions of various spring bulbs visit The University of Illinois Extension Bulbs and More website at web.extension.illinois.edu/bulbs/index.cfm.
Jennifer Fishburn is a University of Illinois Extension horticulture educator.