The companion crops
Turmeric, the golden root
Broad leaves above, a golden root below. On our farm, turmeric will keep the soil between the vanilla vines shaded and damp.
Turmeric (Curcuma longa) is a leafy tropical plant of the ginger family, grown for its bright orange rhizome: the underground stem that is boiled, dried and ground into the spice. It is planted from pieces of rhizome at the start of the rains and dug up about nine months later, when the leaves turn yellow and dry. It likes heat, plenty of rain and well-drained soil, and it copes with partial shade, so it fits between taller crops.
On this page
What the turmeric plant looks like
Above ground, turmeric is a clump of long, broad leaves about a metre tall, a little like a miniature banana plant. Some plants send up a pale flower spike from the middle of the clump.
Below ground is the part people grow it for: a cluster of knobbly rhizomes, deep orange inside, with thinner “fingers” branching off a central “mother” rhizome.
How turmeric grows
- Plant pieces of rhizome with a bud or two, about 4 cm deep, at the start of the rainy season.
- Keep the soil moist but never waterlogged. Turmeric wants about 1,500 mm of rain a year, and rots in standing water.
- Let it grow through the rains while the leaves fill out.
- Harvest after about nine months, around 270 days, when the leaves turn yellow, dry out and start to fall over.
- Dig up the rhizomes. Keep the best as seed for next season; boil, dry and grind the rest for the spice.
Why turmeric will grow on our vanilla farm
On our plot, turmeric will cover the shaded ground between the vanilla vines. Vanilla roots stay close to the surface, so bare soil that bakes dry in the hot season is bad news for them. The turmeric leaves keep the sun off the ground and the soil from drying out.
It is also an old Thai kitchen plant. In Thai, turmeric is ขมิ้น (khamin), which is the name of our turmeric warrior in the series.
Turmeric in the kitchen
Fresh turmeric tastes brighter and more peppery than the dried powder. In Thai cooking it colours southern yellow curry (kaeng lueang) and marinades for grilled chicken.
It goes well with vanilla in warm milk drinks: a pinch of turmeric and a spoonful of vanilla syrup in hot milk make a golden latte.
Questions
How long does turmeric take to grow?
About nine months from planting to harvest. In Thailand it is usually planted at the start of the rainy season and dug up in the cool, dry months.
Can turmeric grow in shade?
In partial shade, yes. It grows well under taller crops and trees, though it gives less in deep shade.
Is turmeric a root?
Not quite. The part we eat is a rhizome, a stem that grows underground, like ginger. The real roots are the thin threads growing from it.
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