When to plant sweet potatoes

Planting dates for sweet potatoes at your ZIP code, from local frost records and extension advice.

Frost risk you'll accept

Historical frost averages plus extension guidance, not a forecast. Check the forecast and soil temperature before planting.

Plant sweet potato slips outside 2–5 weeks after your last spring frost, once the soil is at least 60°F and nights stay warm. If you grow your own slips, start sprouting roots indoors about 4–6 weeks before that planting date. Frost kills sweet potatoes, so there's no benefit in planting early.

Frost tolerance
Very tender: no frost
Soil temperature
Plant out when soil is 60°F+
Days to harvest
90–125 days from planting

The rule we use

Growing your own slips

Sweet potatoes aren't grown from seed. You plant slips: leafy shoots that sprout from a stored root. To grow your own, set a firm, unblemished sweet potato half-buried in moist potting mix or sand somewhere warm, ideally 75–80°F. A heat mat speeds this up. Shoots appear in 2–3 weeks.

When the shoots are 6–8 inches long with several leaves, twist or cut them off the root. Stand them in water or moist mix for a few days and they'll grow roots. One root can give a dozen or more slips over a few weeks.

Planting slips outside

Sweet potatoes want warmth above and below ground. Cold soil stunts them, and a frost kills the leaves outright. Wait until the soil at 4 inches is 60°F or more, which in most places is a few weeks after the last frost.

Plant slips deep enough that only the top leaves show, about 12–18 inches apart, in loose, well-drained soil. Raised rows help the soil warm up and make digging easier. Water well for the first week while the slips root in.

Season length and harvest

Most varieties need 90 days or more of warm weather. In the North, choose quicker varieties and use black plastic to warm the soil. The calendar above warns you if your frost-free season looks short.

Dig the roots before the first fall frost, or as soon as frost blackens the vines, because cold damages roots near the surface. Handle them gently, then cure them somewhere warm and humid for about a week. Curing sweetens them and helps them keep for months.

Seeds and supplies for sweet potatoes

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Questions about planting sweet potatoes

What month do you plant sweet potatoes?

In the South it's usually April to early June. In the Mid-Atlantic and Midwest it's late May to mid-June. In cooler northern areas it's June. Enter your ZIP above for dates from your local frost records.

Can I plant sweet potatoes in March?

Only in frost-free or very warm areas. Elsewhere the soil is too cold in March and a late frost would kill the plants. Use March to sprout slips indoors instead.

How warm should the soil be for sweet potatoes?

At least 60°F at planting depth, and warmer is better. A soil thermometer takes the guesswork out of it.

Is it too late to plant sweet potatoes?

Count the days left until your first fall frost. If you have about 90 or more, a fast variety can still make a crop.

Sources

More crop guides