Dioscorea Japonica Yam is a hardy plant that needs little maintenance, making it a simple addition to many gardens. Once grown, its exceptional resistance to drought means that it requires little irrigation.
Given that yam can become invasive in some situations, more needs to be done to prevent its spread. Dioscorea japonica is a rare type of Japanese mountain yam known as yamaimo. We outline its growth and maintenance practices!
Dioscorea Japonica Yam Overview
| Common Name | Mountain yam, East Asian mountain yam |
| Scientific Name | Dioscorea japonica |
| Days to Harvest | 730 days |
| Light | Full sun to partial shade |
| Water | 1 inch per week |
| Soil | Light, rich, well-draining |
| Fertilizer | Pellet applied after 8 weeks of growth |
| Pests | Birds, mice |
| Diseases | Root rots |
Planting Yamaimo
Plant all of the tubers in late April. Plant a sight that is at least one foot deep and prepare it with rich, light-coloured soil that drains properly. The best is three feet. Growers cultivate Yamaimo wild yams in barrels or plastic tubes in raised beds since the plant is brittle and prone to breaking during the harvest.
If spring has already passed, you might want to sow rooted stem cuttings in the summer. Later in this article, we’ll go into greater detail on the specifics of propagating Japanese yam.
Provide your Dioscorea japonica with a strong trellis when you plant it to aid in its upward growth. A single pole will do for now, but as the vine grows, add extra support. When choosing your planting location, keep this in mind.
Care
Once your Dioscorea japonica plant is grown, you can harvest a Japanese mountain yam. Yamaimo tubers take time to mature, so you’ll have more time to provide the vine care.
Sun and Temperature
Dioscorea japonica requires either full sun or some shade. Make sure it gets six hours of sunlight a day, at least. This sturdy Japanese yam can tolerate temperatures as low as -25 degrees Fahrenheit and as high as 100 degrees.
Dioscorea japonica will wither away in the winter, but the tuber will stay safe in the warm earth and continue to grow. The yam will be better protected from the frozen ground if it is buried deeper if your winters are exceptionally cold.
Water and Humidity
Sustained moisture in the soil is essential for the growth of Dioscorea japonica, the Japanese yam. Make sure the top two inches of the plant are damp but not soggy when you water it every morning. A weekly minimum of one inch of water is ideal.
East Asian mountain yams thrive best when watered with soaker hoses or drip irrigation, but steady, slow watering—as long as the medium drains well and doesn’t become overly wet—will still do the task. Drought is intolerable to Yamaimo.
Soil
Dioscorea japonica grows well in rich, light soil. Grow this wild mountain medicine in a large pot if the soil that makes up your media base is heavy clay. The ideal soil type is light loamy, neutral, or slightly alkaline. Because poor drainage fosters an environment where diseases might spread, good drainage is crucial.
Dioscorea japonica should be grown in a pH range of 6.1 to 7.8. If the acidity of your soil is too high, use modest amounts of garden lime. This glutinous yam requires moist soil; therefore, if your soil is not good at retaining moisture, add some coco coir or sphagnum peat moss.
Fertilizing
After four weeks of growth, in early summer, fertilize your Zhejiang Dioscorea japonica var. japonica or your Dioscorea japonica var. of another variety. Use full-spectrum, slow-release pellet fertilizers at 10-10-10 or 20-20-20.
If you decide to fertilize later in the growing season, be sure to choose a 10-20-20 fertilizer, as it contains both potassium and phosphorus, which will aid in the production of huge tubers.
Pruning
Dioscorea japonica var. can be controlled in spread by pruning. Partially cut the vine to train its shape. Take your time pulling out those male vine-produced little air potatoes so they don’t take over. They usually fall to the ground and spread out quickly.
In the autumn, as the growing season is coming to an end, pruning is also acceptable. After the leaves are all browned, remove all of them, leaving a short 5-inch stem at the base. Mulch will protect it from the weather.
Propagation
Depending on your region, you can multiply any kind of Dioscorea japonica from cuttings in the early to late summer. For those who live in temperate climates, cuttings should be rooted in water in the spring and planted in the early summer.
In Japan, the latter is the most popular spreading tactic. As a result, they will be able to sprout independently.
Harvesting and Storing
Harvesting the tuber has been the greatest component of raising yams in the Dioscorea genus for years. Please proceed with caution, since it is fragile.
Harvesting
After growing from a seedling for two years, harvest your Yamaimo in the autumn, just like other members of the Dioscorea genus. To grow this native to Korea and Japan, simply tilt over the bin and carefully remove the tuber, being careful not to break it if you have prepared a tall planter or plastic tub for it.
Growers of native Dioscorea japonica occasionally put them in plastic sleeves in the soil to facilitate their removal without breaking them. Wait until you’re ready to use the Yamaimo tuber before washing it.
Storing
The tuber will keep fresh for one month if it is wrapped in newspaper and kept in a cold, dry location without being cleaned. If you don’t have access to a cold, dry space in your home, consider keeping food for a few days in the refrigerator. If kept in an airtight container, cooked yamaimo can last up to three days in the refrigerator.
Stored at room temperature in an airtight sack or container, yam powders last for a year. Yamaimo should be grated and used within two weeks of freezing. Other websites suggest slicing the yam, letting it dry, and then storing it in a mason jar at room temperature. I’m not sure how long the yam will keep this way.
Troubleshooting
The only problems you might have with Yamaimo are making sure it has a healthy growing medium and doesn’t go out of control. Let me talk to you about a few things you need to know.
Growing Problems
Make sure the soil is well-drained and light for your Japanese yams. Your tuber will not grow as quickly, and an environment that is conducive to the spread of disease will be created if it is planted in an area with thick clay soil. If not, in the spring of next year, you’ll be picking suckers. To make sure your Yamaimo is adequately supported, use trellising.
With this support, your air potato gets more room to grow, greater exposure to sunlight, and more water. To harvest without taking down a wall, give it a plastic tube or sleeve or set it on an elevated bed. Whole yams can be stored for a longer period than broken ones.
Pests
The worst pest for this yam is nematodes with root knots. These tiny, yellow-to-white worms bore holes in tubers to deposit their eggs. Apply these, diluted with water, to the planting area when the soil temperature is between 42 and 95 degrees.
If you are not careful, mice and birds will devour your potatoes. To save them, use an owl decoy to scare off birds; this should not be a problem at first. But mice and birds might help you keep the vine under control.
Diseases
Root rot can occur in soils with insufficient drainage. Large discoloured splotches will appear on Yamaimo, causing some sections to spoil before you can enjoy them. The disease’s later stages frequently become apparent in storage when the discoloration turns into a mouldy area.
Plant your tuber in some sort of deep barrel if you’re not sure where to plant it. This disease has no known cure. Proliferate an air potato and start over if your tuber becomes diseased.
FAQ
How is yamaimo eaten?
It’s a staple in Japanese soup dumpling dishes, usually grated and made into a paste. It’s also cut, coated in flour, deep-fried in oil, and wrapped with bacon. It can also be used to create connections!
Since recognized botanical kinds of these plants are native to China, Taiwan, Japan, and Korean culinary cultures, they have a wide range of applications. These plants are frequently utilized to improve the noodle’s texture.
Do Chinese and Japanese yams look the same?
Plants from both China and Japan may produce glutinous yams, which can be used interchangeably. Species and hardiness levels vary, even if they are in the same genus.