How To Grow Sweet Potatoes In Containers

If you think you need a big garden to grow sweet potatoes, think again. Learning how to grow sweet potatoes in containers is a fantastic way to enjoy this nutritious crop even in small spaces. With the right approach, you can harvest a generous supply of sweet, homegrown tubers from a patio, balcony, or doorstep. This guide makes it simple.

Container gardening offers control over soil and warmth, which sweet potatoes love. You just need a large enough pot, some slips (which are young plants), and a sunny spot. Let’s get started on your container sweet potato project.

This process is straightforward but requires patience, as sweet potatoes need a long, warm growing season. The key steps are choosing your container, preparing the perfect soil mix, planting your slips, and providing consistent care until harvest time.

Why Choose Containers for Sweet Potatoes?

Containers are ideal for several reasons. They allow you to create the loose, well-draining soil sweet potatoes need, which might be harder in heavy garden clay. You can also move pots to capture maximum sunlight. Most importantly, they confine the vigorous vines, preventing them from taking over your garden.

What You’ll Need to Get Started

A Large Container: At least 20 inches deep and 20 inches in diameter. A half-barrel, grow bag, or large plastic pot works great. Ensure it has excellent drainage holes.
Sweet Potato Slips: These are the starter plants. You can buy them online or from a garden center, or grow your own from a organic sweet potato.
Potting Mix: A light, well-draining mix. Avoid heavy garden soil.
Compost or Aged Manure: For fertility.
Balanced, Low-Nitrogen Fertilizer: Too much nitrogen makes leaves, not potatoes.
A Sunny Location: Sweet potatoes require full sun—at least 6 to 8 hours daily.

Step 1: Selecting and Preparing Your Container

Choose the largest container you can. Sweet potatoes need room for their roots to expand and form tubers. A 20-gallon pot is a good minimum for 2-3 slips. Make sure drainage holes are present; if not, drill a few in the bottom. Cover the holes with a piece of landscape fabric or a coffee filter to prevent soil from washing out.

Step 2: Creating the Perfect Soil Mix

Sweet potatoes thrive in loose, slightly acidic to neutral soil. A good mix is two-thirds high-quality potting mix and one-third compost. You can add a handful of perlite or coarse sand for extra drainage. Fill your container within about 2 inches of the rim.

Fertilizer Notes

Mix in a balanced, slow-release organic fertilizer at planting time. Look for one with a higher phosphorus and potassium number (the second and third numbers on the bag), like a 5-10-10 blend. This encourages root and tuber development over leafy growth.

Step 3: Planting Your Sweet Potato Slips

Plant after all danger of frost has passed and the soil is warm—typically late spring or early summer. Here’s how to plant:

Water the soil in your container until it’s evenly moist.
Gently separate your slips if they came bundled together.
Make holes in the soil about 4-6 inches deep and 12 inches apart.
Place each slip in a hole, burying it up to the first set of leaves. Firm the soil around the stem.
Water the slips in well to settle the soil around the roots.

Step 4: Ongoing Care and Maintenance

Consistent care is simple but crucial for a good harvest.

Watering

Keep the soil consistently moist, especially in the first few weeks and during hot, dry periods. Water deeply when the top inch of soil feels dry. Avoid letting the soil dry out completely, but also don’t keep it soggy. Reduce watering in the last 3-4 weeks before harvest to help the tubers mature and sweeten.

Sunlight and Temperature

Place your container in the sunniest spot possible. Sweet potatoes adore heat. If an early cold snap threatens, consider moving the pot to a sheltered location or covering the plants.

Feeding

About a month after planting, side-dress the plants with a low-nitrogen fertilizer or a bit more compost. Avoid high-nitrogen feeds that promote vine growth at the expense of the tubers.

Managing Vines

The vines will trail beautifully over the sides of the container. You can let them hang or gently guide them. If they get too long, you can trim them back without harming the plant. Just don’t cut them to short.

Step 5: Harvesting Your Container Sweet Potatoes

Harvest time is the best part! It usually comes 90 to 120 days after planting, in early to mid-autumn, just before the first frost.

Stop watering a few days before harvest to dry the soil slightly.
Carefully tip the container on its side and gently pull back the vines.
Use your hands to carefully sift through the soil and unearth the tubers. Be gentle, as their skins are tender at first.
Brush off excess soil; do not wash the tubers yet.

Step 6: Curing and Storing Your Harvest

This step is essential for sweetness and storage life. Cure your sweet potatoes by placing them in a warm (80-85°F), humid place for about 10 days. A sunny spot indoors or near a heater works. After curing, store them in a cool (55-60°F), dark, and well-ventilated place. Properly cured sweet potatoes can last for several months.

Troubleshooting Common Problems

Yellow Leaves: Could be overwatering or a nitrogen deficiency. Check soil moisture and consider a light feed.
Small Tubers: Usually caused by overcrowding, insufficient sun, too much nitrogen, or a short growing season.
Pests: Watch for sweet potato weevils (less common in containers) or flea beetles. Remove affected leaves and use row covers if needed.
Rotting Tubers: A sign of waterlogged soil. Ensure your container has excellent drainage and you’re not overwatering.

FAQ: Your Sweet Potato Questions Answered

Can I grow a sweet potato from a grocery store potato?

Yes, you can sprout slips from an organic sweet potato from the store. Non-organic ones are often treated to prevent sprouting. Place the potato half-submerged in water until slips form, then twist them off and root them in water before planting.

How many sweet potato plants per container?

In a 20-inch wide container, plant 2-3 slips maximum. Overcrowding leads to very small tubers because they compete for space and nutrients.

What is the best container for growing sweet potatoes?

Fabric grow bags are excellent because they provide perfect drainage and air-prune roots. Large plastic pots, wooden barrels, or even a sturdy reusable grocery bag with holes poked in it can work well.

How often should I water sweet potatoes in pots?

Water when the top inch of soil is dry. This may be every other day in hot summer weather. The goal is even moisture, not wet or dry extremes.

Why are my sweet potato leaves turning purple?

This is often normal, especially for certain varieties. It can also be a sign of cool temperatures or phosphorus deficiency, but in healthy plants, it’s usually just a trait of the plant.

Growing sweet potatoes in containers is a rewarding project that yields delicious results. With a big pot, good soil, plenty of sun, and a little patience, you’ll be harvesting your own homegrown sweet potatoes before you know it. Give it a try this season—you might be surprised by your success.