Learn How to Grow Turmeric at Home

• How to Prepare Turmeric after Harvesting

Turmeric is native to tropical areas such as India and Malaysia and can grow as an outdoor perennial in similar warm and humid climates. It can also survive in temperate climates if you dig up the rhizomes and store them indoors. You can also try growing turmeric in containers indoors in all climates, and you can find fresh rhizomes for planting in ethnic food stores or on popular sites on the internet, such as Amazon.com. ^(i.2)

To grow this full-sun to partial-shade plant at home requires moist, loamy, and fertile soil with a pH of 4.3-7.5. It can withstand temperatures of about 50-100°F, but if you are growing turmeric for spice or medicinal purposes, the rhizome buds develop best in temperatures of between 75°F and 95°F and planted in full sun. ^(i.2, 21)

If growing turmeric to harvest the rhizomes, plant them 3-5 inches below the surface of the soil and about 10 inches apart. Use natural mulching materials to encourage growth and discourage weeds. Water newly planted rhizomes and then again, a few days later; after that, water about once a week (depending on rainfall). If planting as a flowering ornamental, lumps of turmeric should be broken up and replanted once every three or four years. ^(i.21)

The rhizomes can be harvested nine to ten months after they have been planted. The lower leaves of the shrub will yellow and the stems will dry out when the plant has matured. Cut the leaves off and gently dig out the rhizome clump and remove the 2-3" offshoots from the main bulb before replanting. ^(i.4)

If you live in a cooler climate and want to dig up and store the rhizome until next season, put some of the cut leaves with sawdust or sand in the storage container with the rhizomes. The leaves have natural pesticide and fungicide properties that can help keep insects and pathogens at bay. ^(i.4)

How to Prepare Turmeric after Harvesting

To maximize freshness of the dried spice, experts recommend curing the rhizomes within a few days of harvesting. Conventional curing of turmeric is a two-step process of boiling and drying: ^(i.4)

1. Boil rhizomes in water mixed with a pinch of baking soda until soft before drying. Test to see if it's done — when you can push the rhizome in with normal finger pressure, stop cooking and drain.
2. Cut into thick slices and spread out to dry in the sun (but take in overnight). If the weather is too humid, using a dehydrator is preferable to avoid fungal growth which could produce aflatoxin — a carcinogenic metabolite substance from Aspergillus flavus and A. parasticus. Properly dried turmeric will snap in half cleanly.
3. Grind with a spice grinder and store in a dark glass container (UV light deteriorates curcumin).

Don't have time to boil turmeric? If you have a microwave, research suggests there's an effective shortcut to curing turmeric. The optimal time to microwave freshly harvested turmeric is 4 minutes at 900-watt power level. ^(i.137)