How Are Yams Grown

If you’re curious about how yams are grown, you’ve come to the right place. Growing these nutritious tubers is a rewarding process that requires patience and the right conditions, but it’s absolutely achievable in your own garden. This guide will walk you through each step, from choosing your planting material to harvesting a plentiful crop.

Yam cultivation is a long-term project, often taking 8 to 12 months from planting to harvest. They are typically grown from small tubers or pieces of a tuber, known as “setts,” rather than from true seeds. These vigorous vines need warm temperatures, deep loose soil, and a sturdy structure to climb on for the best results.

What You’ll Need to Get Started

Before you begin, it’s helpful to gather your supplies. Having everything ready makes the process smoother.

Yam Setts: Purchase certified disease-free “seed yams” or use small, healthy whole tubers from a previous crop.
Growing Space: A sunny spot with at least 6-8 hours of direct sunlight daily.
Soil Amendments: Well-rotted compost or manure, and a balanced, low-nitrogen fertilizer.
Support Structure: A strong trellis, fence, or stakes at least 5-6 feet tall.
Basic Tools: A shovel, garden hoe, and watering can or hose.

Step 1: Choosing and Preparing Your Yam Setts

The quality of your planting material is crucial. Look for firm, small tubers about the size of your fist or healthy cut pieces from larger yams. If cutting pieces, ensure each sett has at least one good “eye” or bud and weighs 4-6 ounces.

Let the cut pieces cure for 1-2 days in a warm, dry place. This allows a protective skin to form over the cut surface, reducing the risk of rot once planted. Some gardeners also dust the cuts with wood ash as a natural fungicide.

Step 2: Preparing the Perfect Planting Site

Yams demand deeply loosened soil for their tubers to expand easily. They thrive in well-draining, sandy loam but can adapt to other soils with proper preparation.

Choose your site after the last frost, when soil temperatures are consistently above 70°F.
Dig individual holes or a trench about 6 inches deep.
Mix the excavated soil with a generous amount of compost or aged manure. Avoid fresh manure, as it can casue root issues.
Create mounds or ridges about 12 inches high and 3 feet apart. This improves drainage and gives the tubers room to grow.

Step 3: Planting Your Yams Correctly

Timing and placement are key. Plant your setts when the soil is warm and all danger of cold weather has passed.

Place one yam sett in the center of each prepared mound or at intervals along a ridge.
Position it with the bud (eye) facing upwards.
Cover the sett gently with 2-3 inches of your enriched soil. Do not pack it down tightly.
Water the area lightly to settle the soil around the sett.

Spacing for Optimal Growth

Give your plants plenty of room. Space your mounds or setts along a ridge about 3 feet apart. Rows should be at least 4-5 feet apart to allow for vine growth and good air circulation, which helps prevent disease.

Step 4: Providing Support and Early Care

Soon after the vines begin to grow, they will need something to climb. Installing your trellis soon after planting prevents disturbing the roots later.

Drive sturdy stakes into the ground near each plant.
Run horizontal wires or twine between stakes, or use a pre-made panel trellis.
Gently guide the young vines toward the support. They will quickly start to climb on their own.

Water the plants regularly to keep the soil consistently moist but never soggy during the first few months. A layer of mulch around the base helps retain moisture and suppress weeds.

Step 5: Ongoing Maintenance Through the Season

Yam vines are relatively low-maintenance once established, but they do need some attention.

Watering and Feeding

Water deeply once a week if rainfall is insufficient, focusing on the root zone. Reduce watering as the tubers near maturity to improve their storage quality. Feed the plants with a low-nitrogen, potassium-rich fertilizer about 6-8 weeks after planting to support tuber development.

Weeding and Vine Management

Weed carefully around the mounds, especially early on. Avoid deep hoeing that could damage the developing tubers. You can pinch back the very tips of the vines if they become excessively long, but this isn’t always necessary. The main job of the foliage is to gather sunlight.

Step 6: Knowing When and How to Harvest

The most exciting part! Harvest typically occurs in late autumn, after the vines have started to yellow and die back. This is a sign the tubers have reached maturity.

Use a garden fork or spade, not a shovel, to minimize damage.
Start digging carefully from the side of the mound, well away from the base of the main stem.
Loosen the soil and gently lift the tuber out. They can be quite deep and large, so take your time.

Be patient during harvest, as the tubers bruise easily. A damaged yam won’t store for very long, so handle them with care.

Step 7: Curing and Storing Your Harvest

Proper post-harvest handling ensures you can enjoy your yams for months.

Curing: Let the harvested yams dry in a warm, shaded, well-ventilated place for about 2 weeks. This heals minor wounds and toughens the skin.
Storing: After curing, store them in a cool, dark, and dry place. Ideal storage temperatures are between 55-60°F. Do not refrigerate, as cold temperatures can harm their flavor and texture.

Check stored yams periodically and use any that show signs of softening first. With good conditions, they can store for several month.

Common Problems and Simple Solutions

Even with good care, you might encounter a few issues.

Yellowing Leaves: Could be natural die-back at season’s end, or a sign of overwatering or nutrient deficiency.
Small Tubers: Often caused by soil that’s too heavy or compacted, insufficient sunlight, or planting too late in the season.
Rotting Setts/Tubers: Usually a result of poorly draining soil or planting setts that weren’t properly cured.
Pests: Watch for nematodes, which can distort tubers, and beetles that chew on leaves. Use crop rotation and remove affected plants.

FAQ About Growing Yams

What is the difference between yams and sweet potatoes?
They are often confused in stores, but they are different plants. True yams (Dioscorea) have rough, bark-like skin and starchy, often white or purple flesh. Sweet potatoes (Ipomoea batatas) have smoother skin and sweeter, moist flesh.

Can I grow a yam from a supermarket yam?
You can try, but it’s not always reliable. Store-bought yams are often treated with sprout inhibitors. For best results, buy certified seed yams from a garden supplier.

How long does it take for yams to grow?
Most varieties require a long growing season of 8 to 12 frost-free months. This makes them ideal for warm climate regions.

Can I grow yams in containers?
It’s challenging due to the depth required for the tuber, but possible with a very large, deep container (like a half-barrel) and a strong support. Choose a smaller-yielding variety if you attempt this.

Why are my yam vines not producing big tubers?
The most common reasons are lack of sunlight, soil that is too heavy or nutrient-poor, or inconsistent watering during the main growth phase. A soil test can help identify nutrient issues.