Germinating the seeds
Getting started -- Plant your seeds when you receive them for best results. Use several small pots or cups with drainage holes, about 2-4 inches (5-10 cm) tall.
A typical soil mix is 3 parts potting soil to 2 parts perlite. An alternate mix is equal parts of coir fiber (or peat moss) and perlite. Don't add lime to the mix, because the plant prefers slightly acid soil.
The seeds are small, so work in a well-lit area. Sprinkle several seeds evenly across the surface of each pot. An easy way to pick up the seeds is by breathing on your finger tip to lightly moisten it, then dabbing the seeds with it. Don't sow them too densely, because the germination rate is high.
After sprinkling them on the soil surface, sprinkle a thin layer of long-fiber sphagnum moss (not ground peat moss). This helps retain moisture around the seeds while allowing light to reach them, which aids germination. This photo shows how much moss to use. If you don't have sphagnum moss, sprinkle a bit of your soil mix around the surface.
Add water until the soil is evenly moist, but not soggy. Until the seeds sprout, ensure that the soil surface never dries out. An easy way to maintain high humidity by enclosing the pots in a plastic container or bag. Leave it open a crack to let in fresh air. Once or twice a day, you may need to drip a few drops of water on the surface to keep it moist.
The seeds germinate well between about 65-80 degrees F (18-27°C). I don't have experience germinating them outside this temperature range. I recommend placing a minimum/maximum thermometer near the pots.
Light helps the seeds germinate, so place the containers in a bright spot out of direct sun. A fluorescent or LED bulb kept 4 inches (10 cm) above them provides the right amount of light. Keep the light on at least 12 hours per day.
The seeds should start sprouting within 4-6 weeks. Continue dripping water on the soil surface after they sprout, since young seedlings have a small root system. Increase the air ventilation slightly after they sprout to prevent rot.
When the seedlings are 1-2 months old, you may carefully dig them up and transplant them, or cut away any slower ones, leaving 1 strong seedling in each pot.
Fertilizing -- For the first 1-2 months, feed weekly with a very dilute (1/8th strength) liquid fertilizer. Hydroponic fertilizer works the best for this, because it is easily absorbed and contains all essential nutrients. After 2 months, you may switch to a slow-release, granular fertilizer and feed every 2 months.
Watering -- Once the seedlings are 4 weeks old, you may stop keeping the soil surface moist at all times. Aim to keep the rest of the soil evenly moist (but not soggy).
Lighting -- The plant likes filtered sun or bright shade + morning sun. Protect it from strong afternoon sun.
Transplanting -- When the seedlings are 2 months old, repot to a 1 quart (1 liter) container. Water the soil before repotting, to keep the soil ball from breaking apart, which can damage the roots.
Climate -- It grows well for me in warm indoor conditions with a drop in temperature at night, similar to intermediate-temperature orchids. I haven't tried it in cooler conditions. I presume it will be unhappy below 55 degrees F (13°C), although its tuber could probably survive a light frost. Over about 50% humidity seems to be best.
If you have any questions or problems, please contact me.
Have fun growing them!
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