Dioscorea polystachya seed
You can plant the bulbetts anytime in the Spring or Summer, but I recommend planting one in a small pot with potting soil or topsoil in the late fall/early winter, cover it with some shredded leaves or a thin layer of wood chips, and label it so you don’t forget what it is. Leave it in the uncovered outside over the winter. In the Spring, you’ll notice green and purple shoots emerging when the temperatures get fairly warm. You can then transplant the contents of the container to the desired location in the garden. Space each plant 4 to 6 inches (10 – 15 cm) apart, depending on how dense you want the foliage to be. For best results, the plants will need something to grow up, like a fence or trellis. I just use poplartrimmings and they seem to work fine.
These bulbetts were produced from plants that were grown without the use of pesticides or added fertilizer. The plant is relatively drought-tolerant. I only water my plants once or twice over the growing season. They seem to appreciate heat and really take off with growth in the summer. In the fall, the foliage turns to beautiful yellow color before falling from the plant. After a year of growth, the plant will
Despite being a relatively uncommon plant grown for food here in the US, Japan apparently produces over 200,000,000 pounds (90,718,474 kg) a year of these plants to eat. The plants grow so easily and produce without needing much, if any, fertilizer so it’s easy to see why it is so popular in Japan. Each of these bulbetts will grow into an individual plant, which will produce dozens (if not hundreds) of its own bulbetts after a year or two of growth. That means once you have one specimen, you would have your own source of new tubers to grow new yam plants year after year.