Planting Depth and Spacing of Spring-flowering Bulbs
Planting Depth and Spacing of Spring-flowering Bulbs
The array of spring-flowering bulbs includes tulips, daffodils, crocuses, hyacinths, snowdrops, and flowering onions. By planting a variety of spring-flowering bulbs, gardeners can enjoy blooming plants from late March to mid-June.
For best selection, visit your local garden center early. Select large, firm bulbs. Avoid soft or blemished bulbs. Store purchased bulbs in a cool, dry location until they can be planted in the fall. October is the ideal time to plant spring-flowering bulbs. To achieve the greatest visual impact, plant spring-flowering bulbs in clusters or drifts. When planting tulips or daffodils, plant 10 or more bulbs of the same variety in a cluster. Smaller growing bulbs, such as Siberian squill, should be planted in drifts of 50 or more. The flowering list provides planting depth and spacing of various spring-flowering bulbs.
| Bulb | Depth* | Spacing |
|---|---|---|
| Allium spp. (Ornamental Onion) | ||
| large bulbs (A. giganteum and others) | 6 inches | 12 to 18 inches |
| small bulbs (A. moly, A. unifolium, etc.) | 3 to 5 inches | 6 to 8 inches |
| Camassia spp. (Quamash) | 4 inches | 4 inches |
| Chionodoxa luciliae (Glory-of-the-Snow) | 3 to 4 inches | 3 inches |
| Crocus spp. (Crocus) | 3 to 4 inches | 3 inches |
| Fritillaria spp. (Fritillaria) | ||
| Fritillaria imperialis (Crown Imperial) | 6 to 8 inches | 12 to 18 inches |
| F. meleagris other small flowering types | 3 to 4 inches | 4 inches |
| Galanthus nivalis (Common Snowdrop) | 3 to 4 inches | 3 inches |
| Hyacinthoides hispanica (Spanish Bluebell) | 4 inches | 4 to 6 inches |
| Hyacinthus orientalis (Hyacinth) | 6 inches | 6 to 8 inches |
| Leucojum vernum (Spring Snowflake) | 3 to 4 inches | 3 to 4 inches |
| Muscari armeniacum (Grape Hyacinth) | 3 to 4 inches | 3 to 4 inches |
| Narcissus spp. (Daffodil) | ||
| Trumpet, large-cupped, etc. | 6 to 8 inches | 6 to 8 inches |
| Miniature and other small bulbs | 3 to 5 inches | 4 to 6 inches |
| Puschkinia scilloides (Striped Squill) | 3 to 4 inches | 3 inches |
| Scilla siberica (Siberian Squill) | 3 to 4 inches | 3 inches |
| Tulipa spp. (Tulip) | ||
| Darwin hybrid tulips, triumph tulips, etc. | 6 to 8 inches | 4 to 6 inches |
| Species or botanical tulips | 3 to 5 inches | 3 to 4 inches |
* Planting depth is measured from the base of the bulb to the soil surface.
This article originally appeared in the September 13, 2002 issue, p. 118.
