Q: After reading a suggestion in your column last winter, I planted a piece of ginger root from the grocery store. It grew outside in a pot all summer. Recently I dug up a few roots and found that they were sweet and delicious. There are, however, even bigger roots growing from the base of the plant. Are all ginger plant roots edible?
A: Glad you had fun with your experiment! The thick roots growing horizontally from the base of the ginger plant are called rhizomes. They are specialized, starch-filled structures. The slender roots that extend downward from a rhizome extract water and nutrients from the soil. A by-product of the energy-storing work of the rhizome is a chemical that gives the nice gingery taste you enjoy.
The newly-grown rhizomes are delightfully edible but the old one you originally planted is too tough and woody to consume. Ginger is not always winter-hardy outdoors in Atlanta. You can bring the plant indoors for the winter or experiment further by planting it outdoors in a protected location. If you don’t care for those two options you can always plant grocery store ginger root next spring.