Sweet potatoes, known for their vibrant colors and sweet taste, are a versatile addition to any garden. These tropical plants, part of the Morning Glory family, thrive in warm climates and are relatively easy to grow. With varieties ranging from orange-fleshed 'Beauregard' to purple 'Stokes', sweet potatoes offer unique traits and flavors. They require minimal care, making them ideal for both novice and experienced gardeners.
- Common Names: Sweetpotato, Sweet potato
- Scientific Name: Ipomoea batatas
- Plant Type: Herbaceous perennial vine
- Plant Height: 1.5 to 13 feet
- Growing Difficulty: Easy
- Growing Time: 90 to 120 days
- Bloom Time: Summer
- Temperature: 60 to 85 degrees Fahrenheit
- Hardiness Zone: 8-11 (Find your hardiness zone here)
- Sunlight: Full Sun
- Soil pH: 4.5–7.0
- Watering Frequency: Water regularly, especially mid-summer
- Plant Spacing: 12 to 18 inches apart
Different Methods to Grow Sweet Potatoes
Planting Slips
Sweet potatoes are grown from slips, which are sprouts from mature sweet potatoes. These slips are twisted off, rooted in water, and then transplanted into the soil.
- Pros: Ensures healthy growth, easy to start, and can be done indoors before transplanting.
- Cons: Requires initial effort to root slips in water, and not suitable for direct planting in the ground.
Growing in Raised Beds
Ideal for areas with clay, rocky, or compacted soil. Raised beds should be 8 to 10 inches high to ensure proper drainage and soil quality.
- Pros: Better drainage, easier to control soil quality, and ideal for poor soil conditions.
- Cons: Requires construction and more initial setup.
Using Containers
Suitable for bush-type sweet potatoes. Requires large containers (10 to 25 gallons) with well-draining, rich soil.
- Pros: Space-efficient, can be moved to optimal sunlight, and suitable for small gardens.
- Cons: Limited root space, requires frequent watering and fertilizing.
Ideal Soil and Location Requirements
Sweet potatoes thrive in well-draining, sandy soil rich in organic matter. They prefer full sun exposure but can tolerate some afternoon shade in hot regions. Ideal soil temperatures should be at least 65°F, with nighttime temperatures above 55°F.
When to Plant Sweet Potatoes
Sweet potatoes should be planted in the spring, 3 to 4 weeks after the last frost, when the soil temperature is at least 65°F and nighttime temperatures are above 55°F. Avoid planting too early to ensure the soil is warm enough for optimal growth.
Growing Sweet Potatoes Outdoors
Growing sweet potatoes from slips is the best method for home gardeners. This method is straightforward and ensures a successful harvest.
- Prepare the soil. Choose a sunny spot with well-draining, sandy soil. Add compost to enrich the soil and ensure it is loose down to 8 to 10 inches.
- Obtain slips. Purchase sweet potato slips from a local garden center or nursery. You can also grow your own slips by placing a sweet potato in water until it sprouts.
- Plant the slips. Create raised mounds 6 to 8 inches tall and about 12 inches wide. Plant the slips 12 to 18 inches apart, ensuring the roots and stem are covered up to the leaves.
- Water generously. After planting, water the slips with a high-phosphorus liquid fertilizer. Continue to water generously for the first 7 to 10 days to help the plants establish roots.
- Maintain the plants. Side-dress the plants with 5-10-10 fertilizer 3 to 4 weeks after transplanting. Weed regularly and water consistently, especially during mid-summer.
- Harvest the sweet potatoes. Harvest when the leaves and ends of the vines start turning yellow, typically about 100 days from planting. Loosen the soil around each plant and dig the roots by hand to avoid damage.
Growing Sweet Potatoes Indoors
Growing sweet potatoes indoors is possible, especially using bush-type varieties in large containers. Here’s a step-by-step guide to help you grow sweet potatoes indoors successfully.
- Choose the right container. Use a large container, ideally 10 to 20 gallons, with plenty of drainage holes to prevent root rot.
- Prepare the soil. Fill the container with a well-draining, rich potting mix amended with compost, sand, bonemeal, and wood ash.
- Plant the slips. Plant the slips 3 to 4 weeks after the last spring frost when the soil has warmed to at least 65°F. Ensure the roots and stem are covered up to the leaves.
- Place in full sunlight. Position the container in a location that receives full sunlight every day, ideally 6 to 8 hours of direct sunlight.
- Water generously. Water the slips with a high-phosphorus liquid fertilizer for the first 7 to 10 days to help the plants establish roots. Continue to water regularly, keeping the soil evenly moist.
- Maintain temperature. Keep the room temperature between 75°F to 80°F to ensure optimal growth.
- Side-dress with fertilizer. Apply a 5-10-10 fertilizer 3 to 4 weeks after transplanting to promote healthy growth.
- Monitor and care. Weed regularly and avoid deep digging. Do not prune the vines, and reduce watering late in the season to prevent cracking the skin.
- Harvest the sweet potatoes. Harvest when the leaves and ends of the vines start turning yellow, typically about 100 days from planting. Loosen the soil around each plant and dig the roots by hand to avoid damage.
- Cure and store. Cure sweet potatoes in a warm place (about 80°F) at high humidity (about 90%) for 10 to 14 days. After curing, wrap each sweet potato in newspaper and store in a high humidity area at 55° to 60°F.
Sweet potatoes are remarkably resilient and can thrive in less-than-ideal soil conditions. An interesting fact is that they can be grown in sandy soil or raised beds mulched with black plastic to keep the soil warm, ensuring a bountiful harvest even in cooler climates.
Caring for Sweet Potatoes
- Watering: Keep the soil evenly moist, especially during mid-summer. Deep water during hot, dry periods to increase yields, but reduce watering late in the season to avoid cracking the sweet potato skin.
- Fertilizing: Side-dress the plants 3 to 4 weeks after transplanting with a 5-10-10 fertilizer. Avoid heavy nitrogen fertilizers, which can lead to lush leaf growth at the expense of the edible roots.
- Pest Management: Common pests include flea beetles, wireworms, and root-knot nematodes. Use row covers to protect against flea beetles, rotate crops to manage nematodes, and choose disease-resistant varieties to minimize pest damage.
- Harvesting: Harvest sweet potatoes when the leaves and ends of the vines start turning yellow, typically about 100 days from planting. Handle the tubers carefully to avoid bruising, and do not wash the roots immediately after harvesting.
- General Care: Weed the beds regularly, starting 2 weeks after planting. Avoid deep digging with tools that can disturb the delicate feeder roots, and do not prune the vines as they should remain vigorous.
Common Challenges With Sweet Potatoes
Sweet potatoes are surprisingly easy to grow, even for novice gardeners. They are heat-tolerant, pest-resistant, and adaptable to various regions, provided the soil is warm and well-draining. The vines root wherever they touch the ground, making it possible for a few plants to produce a generous harvest. In my experience, once you get the slips started, they practically take care of themselves, shading out weeds and requiring minimal maintenance.
However, growing sweet potatoes does come with its challenges. They need a long growing season of at least four months of warm weather and are very tender, requiring protection from late frosts. They prefer sandy, well-draining soil and can struggle in clay or compacted soils. Pests like wireworms and root-knot nematodes can also be problematic. Avoiding heavy nitrogen fertilizers is crucial, as it can lead to lush leaf growth at the expense of the edible roots. Despite these challenges, with a bit of care, sweet potatoes can be a rewarding addition to your garden.
Safety of Sweet Potatoes for Pets
Sweet potatoes are generally safe for cats, dogs, and other pets when cooked and served plain. However, raw sweet potatoes can be harmful. If you suspect your pet has ingested raw sweet potatoes, contact the ASPCA 24-hour hotline.
Frequently Asked Questions
Can I grow sweet potatoes from grocery store varieties?
While it's possible to grow sweet potatoes from grocery store varieties, it's recommended to use certified disease-free slips from a reputable supplier. This ensures healthy plants and reduces the risk of introducing diseases to your garden.
How do I prevent pests like wireworms and nematodes?
To prevent pests such as wireworms and root-knot nematodes, practice crop rotation and choose disease-resistant varieties. Additionally, using row covers and maintaining healthy soil can help mitigate pest issues.
What is the best way to cure sweet potatoes after harvesting?
After harvesting, cure sweet potatoes in a warm place (about 80°F) with high humidity (around 90%) for 10 to 14 days. This process helps to heal any cuts and toughen the skin, making them suitable for long-term storage.
Can sweet potatoes be grown indoors?
Growing sweet potatoes indoors is challenging due to their need for warm weather and large containers with good drainage. It's best to grow them outdoors where they can receive ample sunlight and space to spread.
