The “yum plant” broadly refers to a group of edible root vegetables central to diets across the globe. These versatile tubers have been cultivated for thousands of years, establishing themselves as a dietary staple in numerous cultures worldwide. Their nutritional value makes them a valuable addition to many diets, serving as a primary source of carbohydrates.
Understanding “Yum Plant”
The term “yum plant” often leads to confusion, as sweet potatoes are commonly misidentified as yams, particularly in the United States. True yams belong to the Dioscorea genus, distinct from sweet potatoes (Ipomoea batatas). While both are starchy root vegetables, yams generally have rougher, darker skin and drier, starchier flesh that is less sweet than a sweet potato.
The Dioscorea genus includes over 600 species. Common examples are white yam (Dioscorea rotundata), a staple in West Africa, and yellow yam (Dioscorea cayenensis), grown in the Caribbean. Ube, or purple yam (Dioscorea alata), is recognized for its vibrant purple flesh and use in Asian cuisine. These true yams are native to tropical areas of Africa, Asia, and the Caribbean.
Growing “Yum Plants” Successfully
Cultivating true yams requires specific environmental conditions for a productive harvest. They thrive in tropical and subtropical climates, specifically frost-free zones, preferring warm temperatures between 25°C and 30°C (77°F and 86°F). A full growing season free of cold weather is important, which can range from five to eleven months depending on the variety. For those in cooler climates, growing yams within a greenhouse is an option.
Yams need a location that receives full sun, meaning at least 6 to 8 hours of direct sunlight daily. In hot climates, partial shade during peak heat can prevent overheating.
The ideal soil for yam cultivation is rich, loamy, and well-draining, with a slightly acidic pH ranging from 5.5 to 6.5. Heavy, compacted soil is not suitable as it impedes tuber development. Incorporating organic matter, such as compost or well-rotted animal manure, before planting improves soil fertility and structure.
Consistent moisture is important, especially during their active growing season. They generally require about 40 inches of water over the entire growing season. While yams need regular watering, particularly when young, avoid waterlogging, which can lead to tuber rot. Mulching helps retain soil moisture, suppress weeds, and regulate soil temperature.
Yams are heavy feeders and benefit from regular fertilization. A balanced NPK (Nitrogen-Phosphorus-Potassium) fertilizer, such as a 10-10-20 or 12-12-17 ratio, supports foliage growth and tuber development. Organic options like well-rotted animal manure and compost also provide essential nutrients. Fertilizers can be applied every four to six weeks during the growing season.
Most yam species are vigorous climbing vines, requiring a sturdy support system. Providing a trellis, fence, or stakes allows the vines to climb upwards, ensuring their leaves receive maximum sunlight. Stakes should be positioned near the plant so the vines can twine around them as they grow.
Harvesting and Storing “Yum Plants”
Harvesting yams occurs when the plant’s foliage begins to yellow and die back, usually in mid to late autumn. Yams are ready for harvest between five and eleven months after planting, depending on the variety.
Careful excavation is necessary to avoid damaging the tubers, which can grow quite deep. Use a garden fork to gently loosen the soil around the plant. Any tubers nicked or bruised during harvest should be used promptly, as they are more susceptible to spoilage.
After harvesting, yams benefit from a curing process to extend their shelf life. This involves keeping them in a warm, humid environment for about 10 to 14 days, ideally at temperatures between 30°C and 40°C (86°F and 104°F) with approximately 90% humidity. Curing helps heal minor wounds and toughens their skin, reducing moisture loss and susceptibility to rot during storage.
For long-term storage, cured yams should be kept in a cool, dark, and well-ventilated area, with an optimal temperature range of 13°C to 16°C (55°F to 60°F). Store them loosely in baskets or open paper bags, rather than plastic, to allow for good air circulation and prevent moisture buildup. Regularly inspect stored yams to remove any showing signs of spoilage, such as soft spots or mold.
Culinary Uses and Nutritional Benefits
Yams are a staple in many global cuisines, offering a starchy, earthy flavor. They are commonly boiled, roasted, fried, or mashed, serving as a versatile ingredient in savory and sweet dishes. In West Africa, yams are often pounded into fufu, served with soups and stews. Other popular uses include yam fries, porridges, and additions to stews and curries.
Yams are a nutritious food source. They are a good source of complex carbohydrates, providing energy, and are rich in dietary fiber, which supports digestive health. Yams contain various essential vitamins and minerals, including vitamin C, vitamin B6, manganese, potassium, and copper.
A one-cup serving of baked yams (approximately 136 grams) provides about 158 calories, 37 grams of carbohydrates, and 5 grams of fiber. They also offer about 18% of the Daily Value for Vitamin C and 19% for Potassium. Yams contain antioxidants, which help protect cells from damage.