What Is the Difference Between a Tuber & a Bulb?

True Bulbs

• True bulbs contain the entire life cycle of the plant within the structure. A cross-section of a bulb reveals a miniature plant, complete with its bloom inside the bulb. Bulbs contain everything the plant needs to thrive when provided moisture, sunlight and supplemental nutrients. Some plants that produce true bulbs include lilies, tulips and daffodils.

Tubers

• Tubers are swollen roots that store nutrients and energy for the next year's growth. These structures do not contain plant parts like the bulb does. Instead, tubers store food and energy needed to start a new plant. Some common tubers include potatoes, caladiums, oxalis and anemones.

Bulb Structure

• Bulbs consist of five distinct parts: the outer covering called the tunic, fleshy scales of storage tissue, a basal plate where the roots grow, a shoot that contains the developing flower and lateral buds in the form of bulblets that grow around the perimeter of the bulb.

Tuber Structure

• Tubers are swollen plant tissue that do not have a tunic, or covering, and do not have a basal plate for root growth. Tubers produce shoots in indentations, called eyes, and develop roots from the surface of the tuber. Some plants, such as the dahlia, produce tuberous roots, which look like a group of tubers connected at the crown.

Care

• Both bulbs and tubers of annual plants can be dug and stored for the winter in moist peat moss in a cool, dry place. Dividing the bulbs or tubers and planting them separately increases the number of plants each year. Perennials, such as tulips or daffodils, do not require digging in the fall, but benefit from division every three to five years. Bulblets that grow around the perimeter of bulbs can be separated and planted.