Turmeric is a spice you might not have considered growing before, especially if you live in a climate with cold winters. This amazing spice, a close relative of ginger, is surprisingly easy to grow, even if you live where the snow flies.
Used in many different ethnic cuisines, turmeric comes from the fleshy roots (called rhizomes) of a tropical plant. The turmeric plant (Curcuma longa) is a native of southern Asia, and it’s often dried and pulverized into a powder that’s used to flavor many Asian-inspired dishes. The distinctive yellow pigment of the turmeric root lends its color to curries, pickles and other dishes. But turmeric doesn’t have to be dried and pulverized before using it in the kitchen. The flavor of the fresh root, whether grated or sliced, is slightly zippy and earthy; it’s a favorite at our house. Although this species is native to climates far more tropical than what most of us have here in North America, it’s possible to grow it right here at home.
Sourcing Your Turmeric Rhizomes
To grow this spice, you’ll need to purchase a few rhizome pieces. While you can grow turmeric from grocery store-purchased roots, it can be difficult because these rhizomes may have been treated with a growth inhibitor to prevent them from sprouting in the store. You may have better luck purchasing rhizomes from a small, ethnic grocer who imports roots that have not been treated with growth inhibitors.
Another alternative is to find another farmer who grows it and purchase starter rhizomes from them. Because it’s so easy to propagate from rhizome pieces, once you cultivate your original turmeric rhizomes, you can quickly build up stock of your own.
No matter where you purchase your original turmeric rhizomes from, choose thick, firm roots with a lot of small knobs on them—these knobs are the leaf buds. If possible, look for rhizomes with knobs that are slightly green. That’s a good sign that they’re ready to sprout.
Planting Your Turmeric
Cut or crack the turmeric rhizomes into 2-inch pieces, and then let them sit at room temperature for a day or two to cure. Fill a clean, plastic pot with high-quality potting soil, and soak the rhizomes in tepid water for a few hours before planting them into the pot.
Cover the rhizomes with 2 to 3 inches of potting soil, but don’t plant them too deeply. Although turmeric can be planted anytime, late winter and early spring plantings will perform the best.
To speed growth, after the turmeric rhizomes have been watered in, put the pots on a seedling heat mat (the same kind you use to start seeds). It provides the bottom heat the rhizomes need to quickly to sprout. Put the pots in a bright window or under grow lights for 16 to 18 hours per day. There’s no need to cover the pots with anything. Once the plants sprout, take them off the heat mat.
To keep the rhizomes from rotting, keep the containers well-watered when the soil dries out, but do not let the pots sit in a saucer of standing water. It takes two to four weeks for the rhizomes to sprout. If they fail to do so, they may have been treated with a growth inhibitor, or they rotted in the container. In that case, replant with new rhizomes and fresh potting soil.
Moving Plants Outside
Continue to water and care for your new turmeric plants until the danger of frost has passed. Then move the pot outdoors. Choose a partially shaded spot; particularly in the afternoon. If you’d prefer, the plants can be transplanted directly into the ground. Prior to planting, add some compost to the soil to improve the drainage and fertility of the soil. Dappled afternoon shade, coupled with morning sun, is best.
Turmeric plants should be fertilized every few weeks during the growing season. with an organic liquid fertilizer, such as kelp or fish emulsion. As the plant grows, it will top out at a height between 2 and 3 feet. Turmeric plants are quite pretty, and they may even produce a flower stalk in the late summer.
Water your potted turmeric plant on a daily basis during summer’s heat, and rhizomes planted in the ground should receive about an inch of water per week.
At summer’s end, it’s time to harvest your turmeric. Because the plants are frost-sensitive, plan to harvest several weeks before your first expected frost, soon after the plants begin to naturally yellow and die back. Wear gloves when harvesting as the roots can stain your hands a bright yellow.
To harvest, dig up the plants, brush off any excess soil and cut off all the greens just above the rhizomes. Crack the roots apart with your hands. Keep the largest pieces of rhizome for cooking or to sell to your customers. Save the smaller pieces for replanting, but don’t replant them right away. Instead, store the unwashed rhizome pieces in a plastic bag or container in a cool, dark place. Keep them there until it’s time to pot them up and start the process again in late winter.
Turmeric has a growth cycle of eight to 10 months, and the plants will naturally go dormant after eight to 10 months of growth. If you don’t want to harvest your turmeric all at once, you can move the potted plant back inside before frost arrives. Continue to grow it on a sunny windowsill or under grow lights until the plant naturally dies back on its own. Once the plant completely dies, you can harvest most of the roots, but leave a few in the pot. The ones left in the pot will shift into natural dormancy. When this happens, stop watering and allow the potting soil to dry out. The rhizome will just sit in the pot until late winter, when you should start watering again to encourage another cycle of growth.