Cold hardiness & minimum temperature

Is Sweetpotato (Ipomoea batatas 'Beauregard')cold hardy? Hardiness zone & min temp

Also called Beauregard sweet potato, sweet potato, yam.

More about sweetpotato

About Sweetpotato

Ipomoea batatas 'Beauregard' · also called Beauregard sweet potato, sweet potato · edible

Sweetpotato is a tender, heat-loving trailing perennial in the morning-glory family, grown as an annual for its sweet orange-fleshed storage roots. 'Beauregard' is a fast, high-yielding variety that crops in a relatively short warm season, making it the standard choice for cooler temperate growing. It is planted from rooted cuttings called slips and needs warmth, sun and a long frost-free spell.

Cold limit: USDA 9-11 (frost-tender; grown as a warm-season annual elsewhere) · RHS H1C (21-30°C)

Watch for — Frost and cold damage: Completely frost-tender and stalls in cool soil. Plant slips out only after all frost risk and once soil is reliably warm; use black plastic mulch or cover to raise soil temperature in cooler regions.

What sweetpotato's hardiness rating actually means

Hardiness works differently for sweetpotato: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 9-11 (frost-tender; grown as a warm-season annual elsewhere) — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for sweetpotato as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can sweetpotato go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when sweetpotato can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline sweetpotato

Sweetpotato is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Sweetpotato hardiness — frequently asked questions

Is sweetpotato cold hardy?

Hardiness works differently for sweetpotato: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Sweetpotato is grown 9-11 (frost-tender; grown as a warm-season annual elsewhere); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature sweetpotato can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is sweetpotato?

Sweetpotato is rated USDA 9-11 (frost-tender; grown as a warm-season annual elsewhere) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can sweetpotato survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect sweetpotato from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.