Although similar in name, sweet potatoes are quite different from potatoes. Growing sweet potatoes has different requirements than growing potatoes. Sweet potatoes also belong to the morning glory family, and not the nightshade family like regular potatoes. But similar to potatoes, sweet potatoes have various shapes, sizes and colors.
Sweet potatoes have significant cultural and culinary histories and uses across the globe. Sweet potatoes originated in Central and South America, but early on traveled across the pacific. Using radiocarbon dating, archaeologists discovered prehistoric sweet potato remnants in Polynesia dating back to A.D. 1000 to A.D. 1100.
Seed Savers Exchange does not currently sell sweet potato seed, slips, or plants. However, several listers offer sweet potato varieties on The Exchange.
Growing sweet potatoes from seed can be an incredibly rewarding experience for any gardener. Though more challenging than using slips (rooted cuttings from an existing sweet potato), starting sweet potatoes from seed allows you to grow a wider variety of heirloom and specialty varieties. With careful planning and proper care, you can grow large, beautiful sweet potatoes from seed right in your own backyard.
An Overview of Growing Sweet Potatoes from Seed
While many gardeners are accustomed to buying slips from a nursery or starting slips themselves, growing sweet potatoes from true seed is less common. Here’s a quick rundown of the process
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Choose disease-free, non-hybrid heirloom or open-pollinated seed varieties best suited for your growing zone.
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Start seeds indoors approximately 8-10 weeks before your last expected spring frost. Sweet potato seeds need warm soil (at least 70°F) to germinate.
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Transplant seedlings outdoors only after all danger of frost has passed. Sweet potatoes require a long growing season of at least 90-120 days.
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Amend soil with compost and keep plants consistently warm and moist. Proper care is key!
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Harvest mature roots at the end of the season after vines start to die back. Cure harvested sweet potatoes for best flavor.
While it takes more time and effort than using nursery slips growing sweet potatoes from seed is an incredibly educational and satisfying gardening endeavor. Follow the tips in this guide for the best results!
Selecting the Right Sweet Potato Seed Variety
The first step in growing sweet potatoes from seed is choosing the right seed variety Here are some tips
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Seek out heirloom or open-pollinated seeds rather than hybrids. Hybrid seeds are less likely to produce true-to-type plants.
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Pick a variety suited for your growing zone’s length of season. Look for 90-day varieties for northern climates.
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Consider disease resistance. Some sweet potato varieties are more susceptible to common diseases.
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Choose a variety you’ll enjoy! Select for preferred flesh color, texture, and sweetness.
Reputable companies like Urban Farmer Seeds offer a great selection of non-GMO, heirloom sweet potato seed varieties to choose from.
Starting Sweet Potato Seeds Indoors
Sweet potato seeds need warm, humid conditions to sprout successfully. Here are some tips for starting seeds indoors:
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Start seeds indoors 8-10 weeks before your last expected spring frost date.
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Use small containers or seed trays with seed starting mix. Moisten mix well before planting.
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Plant seeds 1⁄4 inch deep and 1 inch apart. Sweet potato seeds are very small.
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Maintain temperatures of 70-80°F for optimal germination. Consider using a seedling heat mat.
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Keep seeds consistently moist but not soaked. Cover trays with plastic domes to retain humidity.
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Once sprouted, move seedlings to bright, indirect light. A sunny window or grow lights work well.
With proper care, seedlings will be ready to transplant outdoors in 8-10 weeks. Avoid letting seedlings get rootbound before transplanting.
Transplanting Seedlings Outdoors
Sweet potato plants need warm soil and air to thrive. Here are some tips for transplanting seedlings:
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Harden off plants for 7-10 days before transplanting. Slowly expose them to outdoor conditions.
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Transplant after all danger of frost has passed and soil is at least 65°F.
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Space plants 12-18 inches apart in rows 3-4 feet apart.Sweet potatoes spread!
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Dig holes twice the width and depth of the seedling root ball.
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Gently remove seedlings from pots and place in holes. Backfill with soil.
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Water transplants daily for the first week to establish roots.
Choose a sunny location with well-draining soil. In cooler climates, use black plastic mulch to warm the soil and boost growth.
Caring for Sweet Potato Plants
Once planted, sweet potato plants need ample warmth, moisture, and nutrition. Here are some growing tips:
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Consistently water plants to keep soil moist but not saturated. err on the drier side as tubers mature.
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Apply a balanced organic fertilizer or compost tea every 4-6 weeks during the growing season.
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Weed carefully around plants. Sweet potatoes have shallow roots that are easily damaged.
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Use row covers or cloches to protect plants if temperatures drop below 55°F. Cold stunts growth.
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Rotate crops each year to prevent disease buildup in the soil. Sweet potatoes are heavy feeders.
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Monitor for pests like grubs, wireworms, and flea beetles. Pick off pests by hand or use organic treatments if needed.
With attentive care throughout the season, your plants will be ready for harvest in 90-120 days.
Harvesting and Curing Sweet Potatoes
Sweet potatoes reach maturity near the end of the growing season. Here’s how to harvest and cure your crop:
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Harvest potatoes 90-120 days after transplanting when vines start to yellow and die back.
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Carefully dig tubers by hand, taking care not to slice or bruise skins.
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Gently brush off excess soil but do not wash tubers. Damaged skins do not store well.
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Cure tubers for 7-14 days in a dark, humid location (80-85°F and 80-90% humidity). This sweetens flavor.
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Store cured sweet potatoes long term in a cool, dark place 55-60°F. They will keep for several months.
After enjoying months of growth and care, harvesting and curing your own sweet potatoes is incredibly gratifying!
Troubleshooting Common Problems
Growing sweet potatoes from seed does come with some challenges. Here are some common issues and how to address them:
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Leggy seedlings – Increase light exposure and reduce temperature. Consider trimming stems.
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Poor germination – Ensure warm enough soil temperatures and keep seeds consistently moist.
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Stunted growth – Fertilize regularly and protect plants from temperature dips and pests.
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Leaf spots/blight – Improve air circulation. Water at soil level rather than wetting leaves.
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Wilting plants – Check roots for pests. Improve drainage and avoid overwatering.
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Misshapen tubers – Ensure soil is loose enough for unobstructed growth.
Don’t get discouraged! Even experienced gardeners run into issues. Stick with it and you can achieve a beautiful harvest.
While it requires more time and effort up front, growing sweet potatoes from seed can be an extremely rewarding gardening project. You’ll get to produce your own specialized varieties, observe the entire growing process, and learn along the way. With the right planning and care, you can enjoy an abundant harvest of homegrown sweet potatoes from seeds you started yourself. This guide covers the key steps – from choosing seeds to troubleshooting problems. Try growing sweet potatoes from seed this year for a uniquely gratifying gardening experience!
What sweet potatoes crave:
While sweet potatoes can crave less-than-satisfactory soil, they will grow a lot better if you utilize fertilizer. To achieve the best effect, add a continuous-release fertilizer containing potassium approximately two weeks after planting the slips. The potassium will be the third number on the fertilizer label. Follow the fertilizer instructions on how to mix it in with the soil. After fertilizing, add biodegradable mulch, such as grass clippings. Continue to add more mulch for another month after fertilizing, but after that, sweet potatoes don’t require more fertilizer.
Instead of adding a potassium-rich fertilizer, another option would be to feed the sweet potato plants with a liquid fertilizer at planting time and again every two weeks as the plants grow.
How to Grow Sweet Potatoes
Plant sweet potatoes outside when the danger of spring frost has passed, and average temperatures have reached at least 70°F. Sweet potatoes need warm temperatures, so there is no need to hurry and plant them early.
When planting in rows, space plants 12-18 inches apart within a row. Space the rows 3-4 feet apart.
Sweet potato plants grow from slips, as opposed to seed. A slip is a portion of a mature sweet potato that has rooted. To obtain a slip from a tuber, cut a sweet potato in half lengthwise. Bury the slip in damp potting soil indoors.
The time to germination differs between varieties. Generally, sweet potato slips should sprout shoots within a few days after planting when kept in a warm and moist environment.
Transplant the sweet potato slips outside about 6 weeks after shoots sprout. Wait to transplant the slips until the shoots are 4-6 inches tall.
Tip: Instead of sourcing sweet potatoes from the grocery store, buy your slips or seed potatoes from a trusted distributor. This will help to ensure the potatoes are disease-free.
Find a sunny planting site with healthy, well-drained soil. Sweet potato plants prefer full sun, but can tolerate partial shade in a hot and dry climate.
To prepare the soil, till and lay black plastic or black landscape fabric over the rows to help raise the ground temperature. Cut slits in the fabric and plant each slip accordingly.
Tip: Place a flag at the origin of planting. This will help guide digging during harvest.
Water the transplants at planting time. Water well for the first week after planting, or until the sweet potato plants do not look wilted. Generally, the plants should look great after a week of good heat and water.
Sweet potatoes thrive in sandy, well-drained soil. If planting in heavy clay soil, build a mound the length of the row about 12-15 inches high and 18 inches wide. Cover the top of the mound with fabric and follow the instructions above.
Check your sweet potato plants often. Carefully pick up each vine beginning at the flag and lift to prevent rooting. This allows more energy to go to the main plant which will in turn produce larger sweet potatoes. Routine irrigation during the season is unnecessary unless the plants look wilted.
The Ultimate Food Security Crop – How To Grow Sweet Potatoes Almost Anywhere
FAQ
How long does it take to grow sweet potatoes from seed?
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YouTube · Gary Pilarchik (The Rusted Garden)https://www.youtube.comTwo Ways to Grow Sweet Potato Slips & Where to Buy Potatoes (Start …Feb 19, 2025 — you can see the full. size. i would put your water-based starts just like that or your soilbased. starts right onto. there the warmth this stays at …
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Roots Plantshttps://www.rootsplants.co.ukGrowing Sweet Potatoes: UK Beginner’s Guide – Roots PlantsHow to harvest sweet potatoes. Your sweet potatoes will be ready to harvest about 12-16 weeks after planting. This will usually be between August and October. W…
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The Old Farmer’s Almanachttps://www.almanac.comHow to Grow Sweet Potatoes: The Complete GuideSweet Potato Slips Note that sweet potatoes are not grown from seed. Instead, they’re grown from slips, which are sprouts from existing sweet potatoes. Slips ar…
Can I grow a sweet potato from a sweet potato?
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1. Get a healthy sweet potato:Choose an organic sweet potato from the grocery store or one that you’ve kept in a cool, dark place.
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2. Start the sprouts:
- In water: Place the sweet potato (either whole or cut in half) in a jar or glass of water, with the bottom end submerged and the top end exposed. Use toothpicks or pins to hold the potato in place.
- In soil: Bury the sweet potato partially in a container of moist potting soil or sand.
- In water: Place the sweet potato (either whole or cut in half) in a jar or glass of water, with the bottom end submerged and the top end exposed. Use toothpicks or pins to hold the potato in place.
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3. Wait for slips:In a few weeks, green sprouts (slips) will emerge from the sweet potato.
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4. Remove and root the slips:When the slips are about 6 inches long, carefully detach them from the sweet potato. Place the lower end of the slip in a jar of water to encourage root development.
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5. Plant the slips:Once the slips have roots, you can plant them in your garden when the soil is warm enough.
Can you plant a whole sweet potato that has sprouted?
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Slips are ideal:Sweet potatoes grow from slips, which are the sprouts or shoots that emerge from a mature sweet potato.
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Rooting slips:You can remove the slips and place them in water (or a bowl of soil) until they develop roots. Once the roots are about an inch long, the slips are ready to be planted.
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Planting the whole potato:You can also plant the entire sweet potato, as long as it has sprouted, notes a user on Reddit.
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Easy method:Burying the entire potato is a simpler method for growing sweet potatoes.
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When to harvest:Sweet potatoes are ready to harvest when the leaves start turning yellow or 4-6 months after planting.
Can you grow sweet potato vines from seed?
If you still want to try going sweet potato vine from seeds, follow these steps: Presoak seeds for 12 hours in warm water to help with germination. Fill a seed-starting tray with a light, soilless starting mix. Sprinkle the seeds over the tray, spacing them 3 inches apart.