Turmeric is a low growing tropical herbaceous plant, which forms many long thin rhizomes, used to produce spice and dye.
Turmeric can only be grown indoors in the UK and is a little tricky to start with, but once the dormancy of the rhizome has been broken it is easy to grow as a houseplant. You will not be able to harvest much useful turmeric from your plant, although you can use the leaves for flavouring.
Perennial. Only suitable for indoors or a heated greenhouse, even in hot summers. Minimum temperature 18°C
Select fresh, plump, juicy looking roots from raw turmeric sold for food.
Choose rhizomes which look as if they have a little tooth-like bud on one side. Lay them tooth side up in a seedtray containing a mixture of seed compost and grit, just cover the roots, and put the tray in a clear plastic bag. Seal the bag. Keep warm, preferably with bottom heat, at 20°C for at least 3 weeks. When shoots emerge, remove the plastic bag and keep the tray damp, in a warm light place but not in direct sunlight.
Pot on the turmeric roots as soon as the shoots are 5cm high, into shallow 15cm pots. Keep them damp and warm, in a slightly shaded position and feed during the growing season weekly with a general purpose liquid fertiliser. In dry weather plants will benefit from being lightly misted with rainwater daily.
During the autumn reduce watering, and keep the plants fairly dry over winter, when they will need more light. Tumeric hates being in a draught, so site your plants carefully.
Red spider mite can be an occasional problem in older plants: regular misting and keeping the leaves well-washed will reduce this.
Asian and Caribbean shops often sell fresh turmeric, although the quality is variable: sometimes if it has been airfreighted in cold temperatures the roots refuse to shoot, or they may have been treated by dormancy-inducing chemicals.
Turmeric plants are available from a number of nurseries.
If the roots are cut the yellow sap will stain fingers or cloth indelibly.