Turmeric is a tropical plant with useful rhizomes. It is a member of the ginger family (Zingiberaceae) and, like ginger, is considered a spice. Another feature it shares with ginger is a showy flower (although the showy part is actually a bract, not the true flower), which means an additional use for the plant is as an ornamental. The canna-like leaves make planting turmeric an attractive foliage option even when flowers are absent.
|Common Name||Turmeric, common turmeric, turmeric root|
|Botanical Name||Curcuma longa|
|Plant Type||Herbaceous perennial|
|Mature Size||3-4 ft. tall and wide|
|Sun Exposure||Full sun in the far North, partial sun elsewhere|
|Soil Type||Rich, well-drained, and consistently moist|
|Soil pH||Slightly acidic to slightly alkaline|
|Flower (Bract) Color||Burgundy, green, pink, white, yellow, or bicolored|
|USDA Plant Hardiness Zones||8-11 (USDA)|
|Native Area||India and Malaysia|
How to Plant Turmeric
When to Plant
If you live in a mild climate, plant turmeric outdoors in the early spring to give the plant time to mature (around 10 months) for harvesting in the fall. For more accuracy, plant turmeric in the ground when the soil is consistently 55 degrees Fahrenheit and the air temperature hovers around 70 degrees Fahrenheit. Do not expose the plant if temperatures are under 50 degrees Fahrenheit indoors or outdoors.
Selecting a Plant Site
Choose a site in full sun or partial shade with loamy, well-draining soil. For best results, find a garden spot that has morning sun and some afternoon shade.
Spacing, Depth, and Support
Cut rhizomes into 1 to 3-inch long pieces before planting. Each piece should have buds. Let the pieces dry out for a day or two. Plant in the ground 2 to 4 inches deep with the buds pointing up. Give the tubers room to grow (they can grow quite large) by spacing them 3 to 4 feet apart.
In the far North, give your turmeric plant full sun. The further south you are, the more it is advisable to afford it some afternoon shade.
Turmeric likes a rich soil. Adding compost and/or manure helps achieve this. The soil should also drain well.
Turmeric is a plant that tolerates wet soil. At the very least, watch out that its soil never dries out. Turmeric's water needs are considered to be above average.
Because turmeric needs a lot of nutrients, feed it every month. An all-purpose liquid fertilizer works best.
Harvest it in the fall after the first frost, which will produce yellowing, faded foliage. Remove at least a portion of the rhizome each year at the end of the growing season.
To prepare a turmeric rhizome for use as a spice, boil it first. Then let it dry out. Once dry, you grind it into a powder.
How to Grow in Pots
To grow a turmeric plant in a climate colder than zone 8, you can treat it as an annual or grow it in a pot. If you choose to grow turmeric in a pot, plant it in the spring. Take these steps:
- Select a suitable container (or containers) for the plant or plants to grow in. Since turmeric is a fairly large plant, choose large pots (roughly 18 inches across and at least 12 inches deep).
- Buy a couple of rhizomes (more likely available online than at your local garden center). You can purchase organic turmeric at a supermarket.
- Inspect the rhizomes for buds (like the "eyes" on a potato). A small rhizome will have two or three buds on it, which is fine. Larger ones may have more, in which case you should divide them. For example, if each rhizome that you bought has six buds on it, break each rhizome in half and plant two halves in one of your pots and the other two halves in another pot.
- Soak the rhizomes in tepid water for 24 hours. (This is important to do for supermarket-bought turmeric to remove any potential growth inhibiting substances on the rhizome.)
- Plant these rhizomes 2 inches deep in the pot. Keep the buds facing up.
- Keep the pot indoors until nighttime temperatures no longer dip below the 50s (F.).
- When the temperature is consistent, bring the pot outdoors and put it in a sunny spot that is sheltered from high winds.
- Make sure the soil in the pot never dries out. This can be a challenge because the soil in containers dries out more quickly than soil in the ground.
- Increase humid conditions in hot, dry weather by misting the plant's leaves.
If you spot a brown leaf or two, simply prune it out using a clean cutting tool. Brown leaves may mean the plant needs more water. However yellowing, dying leaves are normal when the plant is going into dormancy in the winter.
Turmeric is easily propagated by division in the spring. If you have just one turmeric plant, you can make multiple plants from all of its shoots. Here's how to do it:
- Dig up a mature turmeric plant from a pot or in the ground if you are in a warmer climate.
- Remove excess soil to reveal shoots (they look like fingers), which can be hanging from the bottom of the plant. There should be hairy roots dangling from the shoots, as well.
- If the shoots you divided still have attached foliage, chop leaves off (you can leave short leaves if you desire). Some smaller shoots will not have any leaves or foliage at all.
- Loosen soil and drop the shoots into the ground and cover them up for some protection.
If you are growing turmeric in your summer garden, overwinter the plant by digging the rhizomes up in autumn to store them away for the winter indoors. Cut off the top growth, then store the rhizomes in a cool, dry location. Gardeners typically use peat moss, sawdust, or vermiculite as a storage medium. Keep the storage medium slightly moist throughout winter by occasionally misting it.
If you are growing turmeric in a pot outdoors, overwinter it by moving it indoors in the fall. remove the above-ground portion of the plant. Add water to the pot only sparingly. You do not have to worry about light levels but do keep it somewhere where temperatures will remain consistently in the 50s or low 60s (F.) and return it outdoors once the warm weather returns.
Common Pests and Plant Diseases
Pests may pose a few minor problems. Spider mites can appear when the soil is too dry. Spray them away with water or use insecticidal soaps. Slugs and snails like to snack on the plant's young leaves, which may necessitate some form of control.
Watch for a many types of rot that can affect your turmeric plants, including soft rot, dry rot, Fusarium rot, and rhizome rot. Rot tends to happen when the soil becomes soggy and overwatered.
What is the best month to plant turmeric?
If you live in a mild climate, plant turmeric outdoors in the ground around March. You can still plant turmeric in the ground at that time if you live in a cold region, but the plant will be an annual unless you dig it up for overwintering.
Do you soak turmeric before planting?
It's best to soak a newly purchased rhizome in tepid water for 24 hours before planting. You do not need to soak divided rhizomes as long as they are immediately replanted.
What does turmeric taste like?
Turmeric has a pleasantly bitter taste. It's also used to bring out the flavor of other spices when cooking.
Growing Turmeric and Ginger Indoors. The University of Vermont.