When to plant Tomatillos in Cardiff

Sow seeds in warm compost at 8th March - 23rd March, about 0.5 cm deep. Keep them at 21–24 °C in a propagator or on a warm windowsill, and keep the compost just moist.

Move seedlings on once the first true leaves appear, usually from 22nd March. Handle them by the leaves, not the stem, and pot each one into its own small pot so roots can spread.

Pot plants into larger pots from 5th April as roots fill the smaller ones. Keep them growing steadily with bright light and even moisture, and turn the pots now and then so the plants grow straight.

Begin hardening off from 29th April and finish by 13th May. Stand plants outside for a few hours at a time, out of cold wind and hard sun, then bring them back in at night until they are properly acclimatised.

Plant out from 13th May once the soil is warm and the last frost has passed. Space plants 60 cm apart, water in thoroughly straight away, and use cloches or fleece if cold nights are still forecast.

Set in short canes or stakes from 27th May and tie stems loosely as they grow. Tomatillos are bushy rather than cordon plants, so give them support without pinching out the growing tip.

Start feeding from 27th May once plants are settled, then repeat every 14 days. Use a high-potash tomato feed, water deeply in dry spells, and keep the root area evenly moist rather than letting it dry out and flood.

Pick fruits from 1st August as the husks dry and the fruit fills out. Harvest right through to 28th October, checking every few days, and collect windfalls as well because ripe tomatillos drop easily.