Cucumbers in Brighton

Sow cucumber seeds in December to January in small pots (7-9cm) of seed compost, about 1 cm deep. Keep them at 20–24 °C (e.g. in a propagator) for quick germination. Seeds usually sprout in 7-10 days with warmth and moisture.

After germination, move seedlings to a bright spot (but not in harsh direct sun). When they have true leaves, transplant each into a larger pot (e.g. 12 cm). Handle roots gently to avoid disturbance. Keep the young plants at 18 °C or warmer and water regularly.

Plant the young cucumber into its final greenhouse position once nights are mild (around last frost time). Use a large pot, grow bag, or greenhouse border. Space plants about 45 cm apart (e.g. two per grow bag). Water in well. Maintain a humid atmosphere by misting and avoid cold drafts.

Tie the main stem to a vertical support and encourage it to climb. When it reaches the greenhouse roof or top of its cane, pinch out the tip of the main stem. Pinch out side-shoot tips after they have formed a fruit (leave two leaves beyond each fruit). Remove any male flowers that appear on greenhouse varieties to prevent bitter fruit.

Feed greenhouse cucumbers regularly. After about 3-4 weeks from planting, start using a liquid fertiliser every 10-14 days. Once flowering begins, switch to a high-potash feed (tomato fertiliser) for the rest of the season. Keep the compost moist – cucumbers are thirsty plants.

Cut the cucumbers from the vine with a sharp knife or secateurs – don’t tug them. Greenhouse cucumbers can be picked when they are long, dark green and before any yellowing. Check plants every few days and harvest frequently; with the right care, indoor cucumbers will produce continuously through summer (and into early autumn under warm conditions).