Learn how to grow sweet potatoes at home — from starting slips and planting correctly to harvesting, curing, and storing for months of fresh, homegrown sweetness.
Sweet potatoes deserve far more space in the American home garden than they typically receive. They are productive, nutritious, heat-loving, and remarkably low-maintenance once established — spreading vigorously, suppressing weeds with their dense foliage, and producing an abundant harvest of sweet, flavorful roots from a surprisingly small planting.
The key differences that confuse many first-time sweet potato growers: you don’t plant seeds or tubers — you plant “slips,” which are small rooted sprouts grown from a parent sweet potato. And unlike regular potatoes, sweet potatoes require a long, warm growing season and a unique curing process after harvest that dramatically improves their flavor and storage life.
At Outz News Garden, Maria Walker walks you through the complete sweet potato growing process — from starting slips and selecting the right site to planting, care, harvesting at the right time, and curing for maximum sweetness and storage. For context on building the productive vegetable garden that sweet potatoes thrive in, see our vegetable garden for beginners guide.
Understanding Sweet Potatoes: Not a Regular Potato
According to the University of Maryland Extension, the sweet potato (Ipomoea batatas) belongs to the morning glory family and probably originated in the tropical parts of South America, where it was domesticated at least 5,000 years ago. The large, starchy, sweet-tasting roots are an important vegetable crop worldwide — and one of the most nutritious vegetables any home gardener can grow.
Key distinctions from regular potatoes:
- Different family: sweet potatoes are morning glories (Convolvulaceae), not nightshades. They are completely unrelated to regular potatoes despite the name.
- True roots, not tubers: sweet potatoes are storage roots, not tubers like regular potatoes. They continue enlarging as long as the plant keeps growing — which is why harvesting at the right time matters.
- Propagated by slips, not tubers: you grow sweet potatoes from rooted sprouts (slips) produced by a parent root — not by planting a piece of the sweet potato itself as you would with regular potatoes.
- Heat-lovers: sweet potatoes demand warmth. They grow best in long, hot summers and are killed by frost. This makes them ideal for gardeners in warmer regions and a rewarding challenge in cooler ones.
- Not yams: true yams (Dioscorea species) are an entirely different plant grown primarily in tropical Africa and Asia. What Americans typically call “yams” in grocery stores are orange-fleshed sweet potato varieties.
Choosing the Right Sweet Potato Variety
Sweet potato varieties differ in flesh color, skin color, sweetness, texture, and days to maturity. Choosing the right variety for your climate is particularly important — gardeners in short-season regions (Zone 5 and cooler) should prioritize early-maturing varieties.
Orange-Fleshed Varieties — Most Widely Grown
- Beauregard — the most widely grown sweet potato in the US. Orange flesh, copper skin, excellent flavor, 90 days. Good disease resistance and exceptional productivity. The best all-around beginner variety.
- Covington — a newer variety replacing Beauregard in many regions. Very sweet, uniform roots, excellent storage quality.
- Georgia Jet — one of the fastest-maturing orange varieties (90 days); excellent for short-season gardens in cooler climates
- Garnet — deep red-orange skin with very sweet flesh; excellent fresh and baked
White and Cream-Fleshed Varieties
- O’Henry — creamy white flesh with tan skin; less sweet than orange varieties; excellent texture for savory dishes
- Murasaki — purple skin with white flesh; a Japanese variety with nutty, less sweet flavor becoming popular with specialty gardeners
Purple-Fleshed Varieties
- Stokes Purple — striking deep purple flesh; high in anthocyanins (powerful antioxidants); earthy, less sweet flavor; 120 days — requires a long season
- All Purple — purple skin and flesh; excellent fresh eating and roasting
Step 1 — Starting Slips: Growing Your Own or Buying
Sweet potatoes are not grown from seeds or from pieces of the root like regular potatoes. They are grown from slips — small rooted sprouts that grow from the eyes of a sweet potato root. According to Penn State Extension, slips are sprouts on sweet potatoes from the previous year’s crop and can be bought by mail order, from nurseries, or at farmers’ markets, or grown at home from a previous harvest or from store-bought sweet potatoes.
Option 1 — Purchase Slips (Easiest for Beginners)
Purchased slips from reputable nurseries are disease-free, properly rooted, and ready to plant. They are available from online suppliers, local garden centers, and farmers’ markets in spring. Order or purchase early — slip availability is limited and sells out quickly in popular growing regions. This is the most reliable option for first-time growers.
Option 2 — Grow Your Own Slips (Most Economical)
University of Maryland Extension provides detailed guidance on growing your own slips — a process that takes 6 weeks and can produce all the slips you need from a single sweet potato:
- Start 6 weeks before planting date — typically late March to early April in most of the US
- Choose healthy roots: use certified disease-free sweet potatoes from a garden center or healthy roots from your own previous harvest. Wash store-bought sweet potatoes to remove anti-sprouting chemicals.
- Bedding method: cover the bottom of a shallow container with 1 to 2 inches of coarse sand or soilless mix. Slice each root in half lengthwise and place cut-side-down. Cover with 2 inches of growing mix.
- Keep warm and moist: maintain 75 to 85°F consistently — a heat mat is ideal. Cover with plastic to retain humidity until sprouts emerge.
- Harvest slips: when sprouts reach 6 to 9 inches tall with 3 to 4 leaves, snap or cut them from the parent root with about 1 inch of stem. Place slips in water to develop roots before transplanting (roots develop in 1 to 2 weeks).
- Important: according to Penn State Extension, cut slips at least 1 inch above the soil line to avoid spreading any disease present in the planting material.
Step 2 — Site Selection and Soil Preparation
According to Penn State Extension, sweet potatoes are native to tropical regions of Central and South America and will thrive in summer heat. Their large heart-shaped leaves and branching stems create a nice ground cover that chokes out weeds — but they need space to do it.
Site Requirements
- Full sun — 8 hours minimum: sweet potatoes are heat and light lovers. Partial shade reduces both vine growth and root development significantly.
- Warm soil — 65°F minimum: University of Maryland Extension specifies that slips should not be planted until soil has warmed to at least 65°F. Cold soil causes slips to sit dormant without establishing, increasing disease risk dramatically.
- Space: standard varieties spread aggressively — each plant can cover 4 to 6 square feet of ground. Plant hills 12 to 18 inches apart in rows 3 to 4 feet apart. In small gardens, newer compact varieties like Bush Porto Rico occupy much less space.
- Long growing season: most varieties need 90 to 120 days from transplanting to harvest. In Zone 5 and colder, this means starting slips early, using black plastic mulch to warm soil, and choosing fast-maturing varieties.
Soil Preparation
University of Maryland Extension confirms that sweet potatoes grow best in light, sandy soils but grow well on heavier soils high in clay and amended with organic matter. Key soil preparation steps:
- Loosen soil to 12 to 18 inches deep — sweet potato roots expand as they grow, and compacted soil produces forked, stunted, misshapen roots
- Add 2 to 3 inches of compost and work into the top 8 inches
- Form planting ridges 6 to 8 inches high — University of Maryland Extension notes that planting in ridges allows soil to warm faster in spring, improves drainage, gives roots room to expand, and makes harvesting significantly easier
- Soil pH 5.5 to 6.5 — slightly acidic; sweet potatoes tolerate lower pH better than most vegetables
- Avoid excess nitrogen: high nitrogen produces lush vines and small roots. Use a low-nitrogen fertilizer (such as 5-10-10) rather than balanced 10-10-10 for best root development.
Step 3 — Planting Sweet Potato Slips
- Timing: plant slips 2 to 3 weeks after your last frost date, when soil temperature has reached at least 65°F — typically late May through early June in most of the US
- Use black plastic mulch: According to Penn State Extension, using disease-free slip material and rotating sweet potatoes every 3 to 4 years are the most effective ways to prevent scurf and other soilborne diseases — making certified slip sources an important investment for home growers.
Penn State Extension specifically recommends using black plastic mulch to increase soil temperature and suppress weeds. Laying black plastic over prepared beds 2 to 3 weeks before planting warms soil by 5 to 10°F — critical for early establishment in cooler climates - Planting depth: plant slips 4 to 6 inches deep with 2 to 3 leaf nodes buried. University of Maryland Extension notes that the deeper the planting, the more nodes in the ground, and the bigger the potential yield
- Spacing: 12 to 18 inches apart within rows; 3 to 4 feet between rows
- Water immediately: water thoroughly at planting and keep consistently moist for the first 2 weeks until slips establish. Slips may wilt dramatically for the first few days after planting — this is normal. They will recover as roots develop.
Step 4 — Caring for Growing Sweet Potato Vines
Watering
- Water consistently during the first month of establishment — approximately 1 inch per week
- Once vines begin running vigorously (4 to 6 weeks after planting), sweet potatoes are quite drought-tolerant
- Reduce watering in the final 3 to 4 weeks before harvest — some stress concentrates sugars and improves storage quality
- Avoid overwatering at all stages — sweet potatoes in consistently wet soil develop disease and produce cracked, poorly flavored roots
Fertilizing
- Work low-nitrogen fertilizer (5-10-10) into the soil before planting
- Side-dress with a low-nitrogen fertilizer when vines begin to run
- Stop fertilizing 6 weeks before expected harvest — late-season nitrogen produces lush vines at the expense of root development
Vine Management
Sweet potato vines spread aggressively and can root at leaf nodes where they touch the soil. Occasional lifting and redirecting of vines that are spreading outside their designated area keeps the planting manageable and prevents competing root development that reduces the size of the main harvest roots.
Step 5 — Harvesting Sweet Potatoes at the Right Time
When to Harvest
- Days to maturity: most varieties are ready 90 to 120 days after transplanting slips. Check your variety’s specific maturity date and count forward from your planting date.
- Before first frost — critical: University of Maryland Extension warns that frost will injure the above-ground vines and quickly spread rot into the roots. Harvest before the first frost — ideally when soil temperatures are still above 55°F.
- Test dig: about 1 week before expected maturity, carefully dig up one plant to check root size. If roots are full-size, harvest the entire planting. If small, wait another week and check again.
Harvesting Technique
- Cut vines back to 6 inches before digging to make access easier
- Use a garden fork inserted 12 to 18 inches from the base of the plant to avoid piercing roots — sweet potato roots can spread up to 18 inches from the center of the plant
- Lift carefully — sweet potato skins are delicate when fresh and bruise easily. Every bruise or scratch becomes a potential rot entry point during storage.
- Handle like eggs — place roots gently in padded containers; never throw them into buckets
- University of Maryland Extension advises: if immediate digging isn’t possible, cut away vines and throw loose soil over the rows to protect sweet potatoes from cold
Step 6 — Curing: The Essential Post-Harvest Step
Curing is the step that transforms freshly harvested sweet potatoes into the smooth, sweet vegetable you know from the store — and dramatically extends their storage life. Uncured sweet potatoes taste starchy, have thin skins prone to disease, and store poorly. Properly cured sweet potatoes develop thick, protective skins and convert their starches to the sugars that give them their characteristic sweetness.
Curing Process
- Temperature: 80 to 85°F (warm — this is critical)
- Humidity: 85 to 90% relative humidity
- Duration: 7 to 10 days
- Practical setup: place sweet potatoes in a single layer on newspaper or cardboard in a warm indoor location — a spare bedroom, heated basement, or warm garage. Cover loosely with a damp cloth or newspaper to maintain humidity.
- Do not wash before curing — soil on the skin is fine and doesn’t affect curing
After curing, sweet potatoes improve further in flavor during storage — the first 2 to 4 weeks after curing are actually not the peak eating quality. Flavor continues to develop and improve over the first month of storage.
Storage After Curing
- Store at 55 to 60°F in a dark, well-ventilated location
- Do not refrigerate — temperatures below 50°F damage cell structure and produce off-flavors
- Properly cured and stored sweet potatoes keep for 4 to 6 months
- Check monthly and remove any that show signs of softening or rot to prevent spread
Quick-Reference Sweet Potato Growing Tips
- Plant slips, not seeds or tubers — this is what distinguishes sweet potato growing from regular potato growing
- Wait for warm soil (65°F+) — cold soil significantly delays establishment and increases disease risk
- Use black plastic mulch — warms soil, suppresses weeds, and improves yields significantly
- Use low-nitrogen fertilizer — high nitrogen produces vines, not roots
- Harvest before first frost — frost damage spreads rapidly into roots
- Cure before storing — the step that creates the sweet potato you know and love
- Beginners: start with Beauregard or Georgia Jet — reliable, productive, widely available
Learning how to grow sweet potatoes at home rewards you with one of the most productive and versatile vegetables available to home gardeners. From the vigorous, weed-smothering vines that fill the summer garden with tropical exuberance to the moment you dig up a cache of perfectly cured roots — sweet, smooth, and completely unlike the supermarket versions — sweet potato growing delivers genuine satisfaction at every stage.
Start with purchased slips for your first season to eliminate the slip-growing step. Plant in warm soil through black plastic mulch. Stand back and let the vines do their work through the long summer. Harvest carefully before frost, cure faithfully for 7 to 10 days, and then enjoy the fruits of a patient, rewarding growing season.
Share your sweet potato harvest photos and questions in the comments! And for more warm-season vegetable growing guidance, see our guides on growing tomatoes and growing peppers.
👉 Read Next: Vegetable Garden for Beginners — The Complete Step-by-Step Guide
Maria Walker is a certified horticulturist and gardening specialist with over 15 years of hands-on experience in plant care, garden design, and sustainable growing practices.
She holds a Bachelor’s degree in Horticulture Science and a Master’s degree in Sustainable Agriculture — and has spent her career helping people of all skill levels create beautiful, thriving gardens.
Maria launched Outz News Garden with one simple mission: to make gardening accessible and inspiring for everyone, from first-time planters to seasoned green thumbs.