Sweet Potatoes in Penllergaer

Ipomoea batatas

Sweet Potato
Sweet Potato · Ipomoea batatas

A tender, warm-growing crop for UK gardens, grown from slips rather than true seed. It needs a long, frost-free season, light soil, and plenty of warmth to bulk up properly.

30 cm · Full Sun · Moderate Water

Calibrated to Penllergaer · last frost ≈ 21 Apr

Sow indoors February to March, plant out May to June, harvest September to November. Frost risk November to April.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow indoorsNoYesYesNoNoNoNoNoNoNoNoNo
Plant outNoNoNoNoYesYesNoNoNoNoNoNo
HarvestNoNoNoNoNoNoNoNoYesYesYesNo

Growing guide

Step-by-step instructions for growing Sweet Potato

  1. 01

    Root Slips

    24 Feb to 10 Mar

    Place slips in trays of moist compost at 24th February - 10th March and keep them warm and bright. Pot them on once roots show and shoots are growing strongly.

  2. 02

    Pot On Young Plants

    17 Mar to 31 Mar

    Move each rooted slip into a small pot once the roots fill the starter compost. Keep the compost just moist and give them plenty of light so they do not go leggy.

  3. 03

    Harden Off

    5 May to 19 May

    Acclimatise the plants gradually for 5th May - 19th May by moving them outside for longer each day. Keep them under fleece or in a cold frame at night if temperatures dip.

  4. 04

    Plant Out

    12 May to 21 Jun

    Set the plants in their final position once the soil is warm and all frost risk has passed. Space them apart, water in thoroughly straight away, and use cloches or fleece early on if nights are cool.

  5. 05

    Train Runners

    15 Jun to 10 Aug

    As growth spreads from 15th June, tuck stray stems back into the row and keep weeds down around the plants. Avoid heavy feeding, as that pushes foliage rather than tubers.

  6. 06

    Harvest Tubers

    21 Sept to 5 Nov

    Lift a sample tuber from 21st September once the plants have had enough warm growing time. Harvest the main crop through 5th November before frost damages the foliage, and handle the tubers carefully because their skins bruise easily.

Companion plants

Tap a plant to see why it works (or doesn't) with Sweet Potato.

Plants to avoid

Why companion planting matters

Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.

Suggested varieties

Popular varieties of Sweet Potato to consider

Beauregard

A well-known orange-fleshed type that can crop reliably in a warm UK summer under cover or in a sheltered bed.

Orleans

A popular orange-fleshed variety that suits UK growers looking for a dependable, early-ish crop.

Evangeline

A sweeter orange-fleshed variety that can do well in a long, warm season.

Bonita

A pale-fleshed variety often grown in the UK for a slightly lighter flavour and decent yields.

Sweet Potato guides by town

See how Sweet Potato timing shifts in other towns with different frost dates.