You may plant your tuber when you receive it, but keep the soil almost completely dry until September. Or you may store it in a paper bag in a cool spot until autumn. If you see a wiry shoot emerge in autumn, it is time to plant it (the shoot is the foliage, not the root).
A 1 gallon pot (4 liters) is a good size for 1 tuber, and 3 gallons will hold 3 tubers. For soil, use a well-draining mix. A typical mix is 1 part quality potting soil to 1 part coarse horticultural sand or perlite. An alternate mix is 1 part coir fiber to 2 parts perlite or coarse sand, with some slow-release fertilizer mixed in. Don't add lime to the mix. Plant the tuber 2 inches (5 cm) deep.
In September, water the pot just enough so the soil is lightly moist throughout. Don't let it get any wetter until the leaves appear.
Once it sprouts, you may increase the watering. Give it dappled sun or morning sun, with some protection from strong afternoon sun.
2 weeks after the first shoot appears, feed with a general-purpose fertilizer that contains micronutrients, and repeat 2 months later.
Climate -- It prefers temperatures below 80 degrees (27°C) with nights that are cool (below 65°F / 18°C) and frost-free. It might not thrive in areas that regularly get above 80 degrees from fall through spring, especially if nights are warm. It is said to be able to handle a light, brief frost, but i recommend protecting it from freezing temperatures. It prefers part sun, with protection from strong afternoon sun. Over about 40% humidity is best.
Support -- Give the shoots a thin, vertical support to twine themselves around, such as a tomato cage. If the shoots grow taller than it, you may take a second tomato cage, turn it upside down, and tie it to the first cage.
Dormancy -- The tubers normally go dormant in spring or summer, but it may happen at other times if growing them indoors under lights. If the leaves begin to turn yellow, the tuber may be preparing for dormancy, so reduce the watering to prevent rot. Once the shoots die back, you may dig up the tubers if you wish.
If you have any questions, please contact me.
Enjoy your plant!
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