When to plant Sweet Potatoes in London

Place slips in trays of moist compost at 7th February - 21st February and keep them warm and bright. Pot them on once roots show and shoots are growing strongly.

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.

Acclimatise the plants gradually for 18th April - 2nd May by moving them outside for longer each day. Keep them under fleece or in a cold frame at night if temperatures dip.

Set the plants in their final position once the soil is warm and all frost risk has passed. Space them 30–45 cm apart, water in thoroughly straight away, and use cloches or fleece early on if nights are cool.

As growth spreads from 9th May, tuck stray stems back into the row and keep weeds down around the plants. Avoid heavy feeding, as that pushes foliage rather than tubers.

Lift a sample tuber from 13th August once the plants have had enough warm growing time. Harvest the main crop through 10th November before frost damages the foliage, and handle the tubers carefully because their skins bruise easily.