Bulbs A bulb contains a complete flower, along with all the food it needs to bloom. Bulbs can be treated as either annuals or perennials. All bulbs are perennials, but those not adapted to your climate will not naturalize, multiplying their numbers each year. Tulips, for instance, need winters that get at least as cold as 20 F or they make smaller and fewer blooms each year.
Tulips are usually most satisfactory if new bulbs are purchased each fall.
But other bulbs, such as daffodils, are adapted to much of the United States, and will increase in number each year with a minimum of effort. If you wish to keep bulbs as perennials, feed and water the foliage after the blooming period is past, because it is during this period that energy is being stored in the bulb for next year's flower. You can use bulbs in formal or informal landscapes and in containers. Or bring them into the home as forced winter blooms, as houseplants, or as cut flowers. There are no secrets to growing strong, healthy bulbs, just a few simple principles based on their natural cycle of growth.