Turmeric is a tropical plant. Its rhizomes have traditionally been used both in food preparation and as a medicine. 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 it an attractive foliage plant even when flowers are absent.
|Botanical Name||Curcuma longa|
|Common Name||Turmeric, common turmeric, turmeric root|
|Plant Type||Herbaceous perennial|
|Mature Size||3 to 4 feet 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|
|Bloom Time||July to August|
|Flower (Bract) Color||Burgundy, green, pink, white, yellow, or bicolored|
|USDA Plant Hardiness Zones||8 to 11|
|Native Area||India and Malaysia|
How to Grow Turmeric
It is fairly easy to grow turmeric. This is not a plant that you prune. Your main jobs are to keep it well watered and to shelter the rhizome from cold temperatures. To grow a turmeric plant in a climate colder than zone 8, you have three options:
- Treat it as an annual.
- Grow it in the garden during the summer, then dig the rhizomes up in autumn to store them away for the winter indoors. In this case, you would cut off the top growth, then store them 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.
- Grow it in a pot that can be placed outdoors during the summer then moved indoors in fall, until warm weather returns.
Assuming you choose to grow turmeric in a pot, here is how you would proceed. 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 of it (more likely available online than at your local garden center). Inspect the rhizomes for buds (think of 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. So let's say that each rhizome that you bought has 6 buds on it. You would break each rhizome in half and plant two halves in one of your pots, the other two halves in another pot.
Plant these rhizomes two inches deep in the pot, in early spring. The buds need to be facing up. Keep the pot indoors until nighttime temperatures no longer dip below the 50s (F). At that point, 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. Since turmeric likes humid conditions, increase humidity further by misting the plant's leaves during periods of hot, dry weather.
If you are growing turmeric as an ornamental and wish to overwinter the rhizomes, simply bring the plant back indoors, pot and all, in fall, when the first frost comes, as you would do for other tropical specimens such as:
Since the idea behind overwintering turmeric is to save the rhizomes, you really do not have to worry much about your potted plant once you get it indoors. You can go ahead and 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).
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.
Harvesting Turmeric for Culinary and Medicinal Uses
If you are growing turmeric as a spice or as a medicine, you will want to remove at least a portion of the rhizome each year at the end of the growing season. The rest can be brought indoors as you would when growing turmeric as an ornamental. This way, you have an annual source of turmeric for use in cooking, etc.
Harvest it in fall after the first frost, which will produce yellowing in the leaves. It is the rhizome that you are harvesting because that is the plant part used in food preparation and for medicine.
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.
The rhizome has also had a number of medicinal uses traditionally, including to reduce inflammation.