Yams are sometimes confused with sweet potatoes, but they are a distinct plant requiring specific care and maintenance. Most varieties like plenty of direct sunlight, although some do okay in partial shade or indirect light. As a tropical vining plant, yams also need warm temperatures, high humidity, well-draining soil and a trellis or fence to climb. Water the plants daily in the early stages — just enough to keep the soil moist — then gradually reduce watering as they grow.

Many pests and diseases can harm yam tubers. Common pests include yam scale, mealybugs, termites and nematodes. You must also watch for yam mosaic virus and anthracnose. Manage these threats by maintaining clean growing conditions, choosing disease-resistant plants and using insecticides as necessary. Add mulch around the plant base to retain moisture and limit weed growth.

In cooler zones, you can start yams indoors 6-8 weeks before the last spring frost to ensure a full growing season. Like other tuber-style plants, growing new yams involves using seed yams or “parent tubers.” Sow healthy, whole small tubers or pieces of larger yams in containers with all-purpose potting mix. Keep the soil warm and moist with plenty of light. The seed yams should start sprouting and developing roots in a few weeks. (Note that not all of them will germinate.)

Ground soil is ready for yam planting or transplanting when it remains above 60 degrees. Plant the seed yams or seedlings 12-24 inches apart and 2-4 inches deep. Creating mounds or ridges over the tuber pieces will improve soil drainage. Consider digging a larger hole first, inserting your climbing structure and refilling so it has proper support. For container planting, pots should be 18-24 inches wide and deep for one yam plant. Multiple plants will require larger containers.

Yams do best with regular feeding of a balanced fertilizer. Amend the soil when you first plant them, then add more every 4-6 weeks as a side dressing. If you want to fine-tune nutrients, use high-nitrogen fertilizer early for leaf development, then switch to higher phosphorus and potassium for tuber growth. Yams respond well to organic fertilizers, and these also help the soil structure. Compost, rotted manure and bone meal are good choices. Do testing to see if your garden has specific macro- and micronutrient needs.

Yams are technically an annual vegetable, but proper overwintering allows them to become parent tubers. In warmer areas, you can overwinter yams in the ground, using mulch and frost blankets as necessary to maintain above-freezing ground temperatures. Northern growers should remove any remaining tubers from the ground and store them in a cool, moderately humid area with plenty of air circulation.

Cutting away damaged leaves and thinning crowded areas will encourage healthy growth, reduce disease risk and shape the plant to prevent sprawling. Do your first pruning in the late spring or early summer, then repeat on roughly the same schedule as fertilizing.

Yams can take 6-12 months to fully mature. The vines will start turning yellow when the tubers are ready to harvest. Gently dig ground tubers up with a spade or garden fork; cut or pluck aerial tubers off the vine. If ground freezing is not a concern, you can harvest tubers as needed.