It's a rare gardener who actively dislikes bulbs. From delicate snowdrops and optimistic crocus through flamboyant cannas, bulbs repay minimal effort with maximum display from very early spring through summer's end. Planting and care techniques are easy for beginning gardeners to master, and bulbs can bring color and charm to areas beyond garden beds. Bulbs expand a garden's visual variety and extend a gardener's growing season.
European and American gardeners became familiar with many kinds of bulbs through the expansion of world trade and exploration during the 16th and 17th centuries. Travelers and traders carried home Asian and African discoveries, expanding European curiosity and scientific interest in the natural world. Bulbs such as tulips, daffodils and hyacinths introduced exotic shapes, fragrances and colors to gardens; the Dutch passion for tulips left the national economy in a disastrous shambles in the late 1630s. Hybridizers have contributed even wider varieties, and commercial cultivation has made flower bulbs affordable for most gardeners.
Bulbs generally divide into three groupings: small, early-spring bulbs, often planted informally or "naturalized" into garden and lawn settings; major spring-flowering bulbs; and summer-flowering bulbs. Small, early-spring bloomers include snow-drops, glory-of-the-snow, winter aconite, crocus and scilla. Producing plants often only a few inches tall, small, early-springs can be left in place year round in all but deep Southern growing zones, and they increase planting sizes by producing bulblets. Foliage tends to wither very soon after bloom, making way for major spring bloomers and early annuals.
Major Spring Bloomers
Major spring bloomers are the flowers even non-gardeners can identify, sturdy and colorful validations of spring's promise. Daffodils, tulips and hyacinths are the most popular large spring bulbs, carried nationwide by American nurseries in dozens of varieties. Planted in the fall, except in the deep South, large spring bulbs are suitable for both formal and informal plantings. Given a prolonged period of cold (whether in pots sunk in a pile of wood chips, buried in a bag of peat moss in the garage, or stowed in the back of the refrigerator), major spring bulbs can be stimulated to grow and flower indoors before the ground thaws outdoors. This process, called "forcing," accounts for the bulk of blooming bulbs available for spring- holiday gift-giving. Some forced bulbs bloom again if planted outdoors; others lack the strength for perennial performance.
Some bulbs, among them cannas, ixiais, summer-blooming narcissus varieties, dahlias and tuberous begonias, require spring planting and fall/winter out-of-ground storage. Varieties and planting dates vary slightly, depending on growing zones. In general, though, they go into the ground in May/June, blaze their way through summer heat and are ready for removal around the end of September. As expected from heat lovers, their leaves tend to be large and their flowers larger, in strong reds, yellows, pinks and purples. Tuberous begonias require shade; others welcome the sun. Removed from the ground before the first frost date, summer bulbs can be stored in a cool, dry place and replanted for several years.
Generally, all bulbs are planted the same way. The broad end (root source) goes down in the ground, and the pointier end (leaf and bloom source) points up. (In case of error, most bulbs planted upside down eventually bloom--just a bit later than their right-side-up cousins.) In moderate growing zones (3 through 8), small bulbs are planted at a depth between 4 and 5 inches; larger bulbs are planted 8 inches deep. As with many gardening matters, opinions differ and local climate conditions must be considered. Planting charts, however, are readily available in nurseries and often on bulb packages themselves. (The website Van Bourgondien has a summer planting chart, which is linked in the Resources section; that website includes the more commonly available spring chart as well.)
Expanded Bulb Choices
Texas A&M Extension experts suggest that gardeners extend the definition of flower "bulb" to include plant sources sometimes called corms, tubers or tuberous roots, or rhizomes. In fact, they point out, all these terms refer to a plant source containing nearly all the nutrition needed for growth, in a small, compact, portable package. Extending the definition welcomes day lilies, iris, caladiums and other colors, shapes and textures to the bulb-planting repertoire. Bulbs exist for almost every setting and soil, and for every garden.