A dahlia tuber is the thickened underground root that helps a dahlia plant store the energy it needs to grow.

During the growing season, a dahlia plant’s leaves use sunlight to create energy for the plant. Some of that energy is stored in the tubers beneath the soil, and those reserves help the dahlia survive dormancy and begin growing again when warmth returns.

Dahlia tubers are sometimes incorrectly called “bulbs,” but they are actually tuberous roots. Unlike a potato, which can sprout from several places across its surface, a dahlia’s new growth comes from an eye located near the crown, where the tubers connect to the previous year’s stem.

This means that a dahlia tuber needs three basic parts to grow into a new plant:

• a tuber that holds stored energy
• a crown where the new growth develops
• at least one viable eye

The tubers in a clump may look very different from one another. Some are long and slender, while others are short and round. Size and shape do not necessarily tell you how well a tuber will grow. Even a slightly wrinkled tuber can produce a strong, beautiful plant as long as it has a healthy crown and a viable eye that can become the first stem of the new plant.

It is amazing to think that everything a dahlia needs to begin another season is waiting inside that humble little tuber!