Sweet potato season: when to plant sweet potatoes 🍠
Sweet Potato takes 90–120 days to mature, spaced 12" apart at 4" deep. Start indoors and transplant for the longest harvest.
Sweet potato season is defined by warmth, not the calendar. Slips go into the ground 2–4 weeks after your last spring frost, once soil at 4" deep holds 65°F, and tubers come out any time from August (zone 9–10) through mid-October (zone 5–6), always before the first hard frost. The table below gives exact dates for your zone.
Planting dates by USDA zone
| Zone | Transplant | Harvest |
|---|---|---|
| Zone 3 | June 15 – June 29 | August 31 – September 28 |
| Zone 4 | June 5 – June 19 | August 21 – September 18 |
| Zone 5 | May 22 – June 5 | August 7 – September 4 |
| Zone 6 | May 6 – May 20 | July 22 – August 19 |
| Zone 7 | April 22 – May 6 | July 8 – August 5 |
| Zone 8 | April 5 – April 19 | June 21 – July 19 |
| Zone 9 | March 7 – March 21 | May 23 – June 20 |
| Zone 10 | February 20 – March 5 | May 7 – June 4 |
Dates are averages — adjust ±1–2 weeks for your microclimate. Need your exact dates? Enter your zip code below.
Get your personalized sweet potato planting dates
Care tips
- Plant slips after soil hits 65°F.
- Use black plastic mulch in cooler zones to boost soil temp.
- Cure tubers at 80°F for 10 days for sweetness.
Good companions
Beans, Beet, Thyme.
Read more: Companion planting chart for vegetables
Sweet potato season by region
Sweet potatoes need 90–120 warm days with soil temperatures at 65°F or higher. That single requirement drives every regional planting window:
- South (zones 8–10): Plant slips from late April through early June, harvest August–October. Two crops possible in zones 9–10 with early short-season varieties like Beauregard.
- Mid-Atlantic & Midwest (zones 6–7): Slips go in Memorial Day weekend, harvest before first frost — usually mid-September to mid-October.
- North (zones 3–5): Only doable with black plastic mulch, low tunnels, or a heat-loving short-season variety (Georgia Jet, Porto Rico). Transplant mid-June, harvest first week of October.
When can you plant sweet potatoes?
The rule is soil temperature, not calendar date. Wait until soil at 4" deep reads 65°F for three days in a row. Slips planted into cold soil (below 60°F) will sit, sulk, and often rot before they root. In most of the US that lands 2–4 weeks after your last spring frost — much later than most vegetables.
Japanese sweet potato season
Japanese sweet potatoes (Murasaki, Satsuma-imo) need the same planting window as orange varieties but slightly more time — plan for 100–130 days to maturity. In the US they're a warm-zone crop (7 and warmer). Harvest peaks late September through November, with cured tubers hitting peak sweetness after 2–4 weeks of storage at 55–60°F.
How to grow sweet potatoes: the short version
- Order or grow your own slips — one slip per foot of row.
- Build loose, sandy raised mounds 6–8" tall. Compacted soil = knobby tubers.
- Plant slips deep enough to bury the bottom two leaf nodes.
- Water heavily the first two weeks, then only during drought.
- Stop watering entirely 3 weeks before harvest to firm up skins.
- Dig on a dry day before frost; cure at 80°F for 10 days.
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Frequently asked questions
When can I transplant sweet potato seedlings outdoors?▾
Transplant sweet potato seedlings about 3–5 weeks after your average last spring frost. In zone 6 that's around May 6–May 20.
How long does sweet potato take to grow?▾
Sweet Potato typically takes 90–120 days to mature, with harvest beginning roughly 14–18 weeks after the last spring frost.
When is sweet potato season?▾
Planting season for sweet potato slips runs from late April (zones 9–10) to mid-June (zones 4–5), always after soil reaches 65°F. Harvest season runs August through October, and cured sweet potatoes stay in season in storage from October through late winter.
When can you plant sweet potatoes?▾
Plant sweet potato slips 2–4 weeks after your average last spring frost, once soil at 4 inches deep reads 65°F for three consecutive days. Slips planted into soil below 60°F stall and often rot.
How long does the sweet potato growing season last?▾
Sweet potatoes need 90–120 frost-free days from slip planting to harvest. In warm zones (8–10) the season runs late April through October. In cooler zones (5–7) it's late May through late September, with black plastic mulch strongly recommended.
Can I grow sweet potatoes in a cold climate?▾
Yes, in zones 4–5 with two adjustments: choose a short-season variety like Georgia Jet or Beauregard (90 days), and use black plastic mulch or low tunnels to warm the soil. Expect smaller tubers than a Southern crop.
Are sweet potatoes the same as yams?▾
No. True yams are a separate tropical crop (Dioscorea) rarely grown in the US. What American grocery stores label 'yams' are actually orange-fleshed sweet potatoes. All planting advice on this page refers to Ipomoea batatas — sweet potatoes.