Turmeric is one of our favorite herbs and is an interesting and distinctly tropical looking plant that can be grown in the ground as far north as zone 7b in the right situation. It can even clean your soil of harmful pathogens and many pest insects.
These have been tenderly raised and harvested by us, The Freeman Family Farm, in the strictest organic method, in our very own hand-crafted soil. Soil that is supplemented with beneficial bacteria from compost tea, bat guano, worm castings, and naturally occurring minerals; we even add volcanic ash from an active volcano. Your rhizomes are top-of-the-line premium.
Zones 8a to 7b, mulch heavily (at least 6-8 inches thick) in the winter and you shouldn’t have to dig up and overwinter indoors. If doing this in these zones, it helps to cover the site with mulch after the soil is dry, then a layer of plastic for waterproofing, then another layer of mulch – it doesn’t like cold and wet – cold and dry wins. When planting outdoors in these zones, and you intend to overwinter in place, be sure to plant at the top of a slope or mound.
Common name: Turmeric
Botanical name: Curcuma longa
Type: Herbaceous perennial in tropical zones
Scarification/Stratification: None needed for these pre-germinated rhizomes!
Ideally, soak rhizome in room temperature kelp water for 12 hours before sowing, it helps speed things up.
Hardiness: The foliage is not frost tolerant but as long as a heavy mulch is laid, root will over-winter in temperate gardens of zone 7b or higher. See narrative above for more information. Most growers dig up and overwinter rhizomes in a cool dark place, then replant in the spring. If done like this, you can snip off a good bit of root for consumption and/or multiplication of plant stock.
Sun requirements: Moderate light for germination (temperature is more important than light). In front of an indoor window is sufficient. If direct-sown, in a place with morning sun. After germination, the leaves will wilt in the hottest hours if in full sun, but springs back beautifully after shade hits it.
Water requirements: For germination, slightly damp soil. The rhizome has plenty of its own water. Once established, still moderate water.
Sow temp/season: If in zone 7b or higher, direct-sow in the container or garden bed it will grow in, in soils of 72-85F. This makes a bigger root system than transplanting. Some growers direct-sow plugs and lay down clear plastic to raise soil temperature (for germination, not for overwintering as mentioned in the narrative.)
Sow depth/spacing: Sow plugs two inches deep at 18 inch spacing, with the eyes pointing upward.
Germination time: Not applicable for these pre-germinated rhizomes!
2-4 weeks depending on temperature and conditions. Sometimes longer, do not give up!! Temperature is key here.
Final spacing: 18 inches to 2 feet
Final height/spread: We’ve had a plant reach five feet tall and two feet wide in one growing season.
Companion plants: Turmeric grows well with most plants. I would avoid growing turmeric near fennel though, simply because fennel only likes to be planted with dill nearby. Picky thing! I highly recommend planting turmeric next to plants that are susceptible to fungus, soil-borne diseases/pathogens such as heirloom tomatoes, cucumbers, peppers, roses, fruit trees (apples especially), and melons. Avoid planting too close to root crops that would encroach on their allotted space. Because turmeric has the same antibacterial thing going like garlic, it cleans the soil and repels fungal issues – the soil ends up cleaner. A personal observation is that turmeric as a companion plant helps prevent blight – especially with heirlooms.
Pest and disease resistance/susceptibility: Much of this is covered in the section above, Companion Plants. Turmeric has many health and disease inhibiting compounds for humans and plants alike. As such, turmeric is resistant to most soil-borne diseases and pest insects except root rot and gophers, which is easily avoided by not drowning them and not having gophers! The soil turmeric is grown in becomes infused with its disease-fighting and pest-repelling compounds, which are many. We have been growing turmeric for several years in NC, and have not had any pests on it.