When to plant
Plant rooted slips (not seeds or tubers) 2–3 weeks after last frost when soil is above 18°C. Sweet potatoes need 4–5 frost-free months to produce a good harvest. They grow best in warm summers. In cool climates, use black plastic mulch and the warmest, most sheltered spot.
Soil & site
Sweet potatoes thrive in light, loose, well-drained sandy soil. pH 5.5–6.5. They are one of the few vegetables that actually prefer poor, less fertile soil — rich soil produces large tops and small roots. Avoid waterlogged ground. Raised mounded rows work best.
Feeding
Light feeder. A single application of a low-nitrogen, high-potassium fertilizer (like 5-10-10) at planting is usually all that's needed. Too much nitrogen produces lush vines and small tubers.
Common problems
Wireworm (tunnelling damage from soil larvae — rotation and resistant varieties help). Weevils (most serious pest in warm climates). Scurf (dark skin patches) from wet, cold soil. Fusarium root rot in poorly drained soil.
When to harvest
Sweet potatoes are ready 90–120 days after planting slips. Harvest when the roots are a good size (visible by gently probing the soil near the base). The tops may begin to yellow in fall. Always harvest before the first frost — frost damage ruins sweet potatoes quickly.
How to harvest
Cut vines back to 15 cm before digging. Use a fork and dig carefully — sweet potatoes bruise easily. Work 30 cm from the plant and lever soil upward gently. Handle with extreme care as damaged skins invite rot. Cure immediately after harvest — do NOT wash.
Storage & use
Curing is essential: store at 29–32°C with high humidity (85–90%) for 10–14 days immediately after harvest. This heals cuts and converts starches to sugars. After curing, store at 13–16°C in a dark, dry location for up to 6 months. Never refrigerate sweet potatoes.
Companion planting
Sweet potatoes fix nitrogen and grow well with beans. Their spreading vines shade out weeds.
Useful for growing sweet potato
A few things that make this one easier — chosen for this plant, not a generic list.
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