Underground, a bulb is a compact storage organ that lets certain plants survive drought or cold. It consists of a short stem base surrounded by fleshy scales that hold food reserves. When conditions improve, the bulb sends up leaves and flowers using those stored nutrients.

Tulips, daffodils, lilies, and onions are classic examples. True bulbs differ from corms, tubers, and rhizomes, though gardeners often use the word loosely for all of them. Planting depth, soil drainage, and a period of cool temperatures determine how well a bulb performs. After flowering, the foliage must stay green long enough to replenish the bulb for next year.

Many bulbs naturalize in the right spot, multiplying into drifts over time. Others need lifting and drying once the leaves yellow. Proper storage keeps them firm and free of rot until the next planting season.

• Stores food in fleshy scales
• Produces leaves and flowers from underground
• Includes tulips, daffodils, and lilies
• Requires good drainage to avoid rot