Tulips, daffodils and crocus are stars of spring in Midwestern flower gardens. But there's an array of supporting players, often referred to as "minor" bulbs that can add variety to your spring bulb display.
Winter Aconite (Eranthis hyemalis) brings a splash of yellow, buttercup-type blooms on dwarf, 3- to 6-inch plants. Winter aconite is appropriately named for its early arrival, often pushing its blossoms through a cover of snow in February, though sometimes as early as January and as late as March. Plants do well in partial shade to full sun, though they do need a good supply of moisture if in full sun.
Snowdrops (Galanthus sp.) are perfectly named for their snow-white blossoms that gracefully nod toward the ground, which is often still covered with the winter white stuff. Snowdrops are best planted in partial shade.
Glory of the Snow (Chiondoxa sp.) brings clusters of star-shaped blooms in purple, rose or white in late winter or early spring. Glory of the Snow performs best in full sun.
Squill (Scilla sp.) includes a number of species of early spring bloomers and though the blue squill is the most common, there are also white and pink selections. Several species are native to woodland habitats and do best in partial shade.
Striped Squill (Puschkinia scilloides) blooms about the same time as snowdrops and has pale periwinkle blue-striped petals. Striped squill tolerates full sun to partial shade and prefers moderately moist, but well-drained soil.
Summer snowflake (Leucojum sp.) blooms a bit later in mid to late spring, with white, nodding flowers accented at each petal tip with a greenish-yellow splotch. Summer snowflake does well in partial shade to full sun.
Although many gardeners are familiar with the large, lollipop types of Alliums (ornamental onion), the lesser-known Lily Leek (Allium moly) bears bright yellow, star-shaped blooms in mid to late spring. Allium does best in full sun.
Local weather conditions and microclimates can affect the season of bloom. Southern areas of the country could be up to three weeks ahead of northern areas. Urban areas tend to be warmer than rural areas, and even certain areas of one garden can be warmer than others. Flowers that receive reflected heat close to buildings and those in sunny spots tend to bloom before ones that are in the yard or in shady areas.
Spring-flowering bulbs should be planted in fall, approximately six weeks or so before the ground is expected to freeze. This allows the bulbs a chance to grow an adequate root system before winter. Spring-blooming bulbs also need a period of chilling to initiate their flower buds deep in the bulb.
More information about flowering bulbs can be found in "Flowering Bulbs," Purdue Extension bulletin HO-86.