What are yams?
Yams are a starchy tuber vegetable that belong to the Dioscoreae family. They originated in Africa and Asia and have been an important food source for centuries. There are over 600 varieties of yams and 95% of commercially available yams are grown in Africa. The most common yam varieties are white yams and yellow yams. Yams are not the same as sweet potatoes, which are part of the morning glory plant family. Yams have brown, rough, bark-like skin and white, purple, or pink flesh. They can grow up to 1.5m long and 70kg in weight. Yams contain high amounts of vitamin C, potassium, manganese, and fiber.
Why regrow yams?
There are several benefits to regrowing yams instead of buying new tubers each time:
– Cost savings – Regrowing yams is much cheaper than purchasing them. You can get multiple harvests from just one yam.
– Sustainability – Regrowing yams reduces the environmental impact of excessive yam production. It also gives you a local food source.
– Control – You can control the quality and growing conditions when you regrow your own yams. This allows you to avoid chemicals, pests, and disease.
– Preservation of varieties – Heirloom and rare yam varieties can be preserved by regrowing the tubers each season.
– Connection – Regrowing a food source can provide a sense of satisfaction and connection with the land and your food.
How to regrow yams
Regrowing yams is a simple process that only requires a few steps:
1. Select a healthy parent yam
– Choose organic, pesticide-free yams when possible. Select yams that are mature, firm, and free of mold, bruises, and decay.
– Small to medium-sized yams often grow the most productive plants. Very large yams tend to yield less.
– For best results, use yams from your own garden or local farmer. Store-bought yams may be treated with chemicals to prevent sprouting.
2. Encourage sprouting
– Store whole, unpeeled yams in a warm, humid location for 2-3 weeks. A temperature around 70°F is ideal. High humidity prevents drying out.
– Turn the yams periodically and inspect for sprouts. Sprouts will begin forming from the tuber’s eyes.
– When the sprouts are 1-2 inches long, the yam can be planted.
3. Plant in fertile soil
– Yams prefer loose, well-draining soil high in organic matter. Amend clay or sandy soils with compost or manure.
– Plant sprouted yams 3-4 inches deep, with the sprouts facing up. Space plants ~3 feet apart.
– Soil temperature should be at least 70°F. Consistent moisture is key. Add mulch to retain water.
4. Provide supports and care
– As vines grow, install trellises, frames, or poles for support. Yams can vine up to 10 feet.
– Water 1-2 inches per week. More water is needed during flowering and tuber growth.
– Apply a balanced organic fertilizer or compost monthly. Yams are heavy feeders.
– Weed and mulch around plants. Cut back excessive foliage if needed.
5. Harvest
– Yams take 6-10 months to reach maturity. Time varies by variety.
– Harvest when vines die back and begin to dry. Use a fork to loosen soil and carefully unearth tubers.
– Cure freshly dug yams for 1-2 weeks in a warm, shaded location prior to storage or consumption.
– Select smaller yams with some skin attached to use as seed tubers for the next planting.
Troubleshooting
Following proper growing guidelines helps prevent issues. Here are some potential problems and solutions:
Poor germination
Issues: Sprouts don’t form or are small and brittle. Plants fail to establish after planting.
Solutions:
– Start with viable, sproutable seed tubers without chemicals applied
– Allow yams to pre-sprout for longer duration
– Increase heat and humidity during sprouting
– Check soil temperature and moisture levels
Poor vine growth
Issues: Vines are stunted or smaller than expected. Leaves are diseased or yellowing.
Solutions:
– Test soil and adjust pH to 5.6-6.7 range
– Improve drainage in overly wet soil
– Apply balanced organic fertilizer
– Ensure adequate but not excessive irrigation
– Inspect plants for pests or diseases
Small tubers
Issues: Tubers are underdeveloped at harvest. Yields are low overall.
Solutions:
– Provide trellises/poles and prune excess foliage
– Plant in fertile soil and replenish nutrients
– Allow tubers adequate time to size up before harvest
– Maintain consistent moisture during tubering stage
– Start with smaller seed tubers rather than large ones
Alternative propagation methods
While sprouting tubers is the most common regrowth method, yams can also be propagated by:
Vine cuttings
– Take 6-12 inch cuttings from vines during active growth
– Remove lower leaves and plant cuttings in soil or water
– Keep warm and humid until rooted
– Transplant rooted cuttings to soil
Tissue culture
– Under sterile lab conditions, small tissue pieces are excised
– Tissue cultures are grown on gelled media with nutrients
– Plantlets are transplanted; takes less time than tubers
Mound layering
– Bend vines to ground and cover a section with soil
– Allow nodes to root in place before severing vine
– Cut rooted section and plant
Storing yams
Freshly harvested yams will keep for 1-6 months depending on the storage method:
Curing
Curing freshly dug yams for 1-2 weeks improves skin set and wound healing. Allows proper sprout development later. Store cured yams at 55-60°F.
Clamp storage
Mound soil over yams left in the ground. Keeps yams dormant and minimizes sprouting/decay.
Root cellars
A dark, 55-60°F root cellar provides ideal cool, humid conditions for long-term yam storage.
Controlled atmosphere
Storing yams in sealed rooms with temperature, humidity and air composition controlled can extend shelf life. This method is primarily used commercially.
Storage method | Approximate storage time |
---|---|
Curing | 2-6 months |
Clamp storage | 4-6 months |
Root cellar | 4-6 months |
Controlled atmosphere | 6-12 months |
Health benefits of yams
Yams offer a variety of nutritional and medicinal benefits:
Great source of complex carbohydrates
Yams are an excellent source of energy-providing complex carbohydrates. Unlike simple carbs, these digest more slowly without spiking blood sugar.
High in fiber
The fiber content in yams promotes healthy digestion and gut bacteria. Fiber also helps regulate cholesterol and blood sugar levels.
Rich in antioxidants
Orange-fleshed yams contain beta-carotene. This converts to vitamin A, boosting immunity and eye health.
Contains vitamin C
Vitamin C in yams acts as an antioxidant and aids iron absorption. It also supports immune function.
Good source of potassium
Yams provide potassium, an essential mineral and electrolyte that regulates fluid balance and nerve transmission.
May reduce inflammation
Compounds in yams may help control inflammation linked to health problems like arthritis, gout, asthma, and inflammatory bowel disease.
Potential anticancer benefits
Antioxidant and anti-inflammatory properties of yams may help protect against certain cancers like colorectal cancer.
Delicious ways to eat yams
Here are some tasty ways to serve yams:
– Roast chunks with olive oil, cumin, chili powder, salt and pepper
– Steam and mash with butter, brown sugar, cinnamon, and nutmeg
– Bake into custards, breads, muffins, cookies or granola bars
– Fry into yam fries or chips
– Grill into kebabs with vegetables and meat
– Puree into soups, stews or casseroles for a creaminess without dairy
– Dehydrate slices into yam chips
Conclusion
Yams provide a versatile and nutritious edible tuber that can be regrown season after season. With proper selection of seed tubers, care of vines, and harvest and storage considerations, home gardeners can enjoy a sustainable supply of yams. Regrowing yams preserves delicious heirloom varieties while contributing fewer food miles to the family table.