Cucumber

Plant cucumbers outside only after the last frost — late May to June in most of the UK. They are tender plants that need warm temperatures. Under glass, planting can begin in April.

Bitterness in cucumbers is caused by a compound called cucurbitacin, produced in response to stress — particularly irregular watering, temperature fluctuations, or root disturbance. Keep plants consistently watered and avoid soil drying out between waterings.

For indoor varieties (most greenhouse cucumbers), yes — remove male flowers to prevent pollination, which causes seeds to develop and fruit to taste bitter. Outdoor varieties need pollination, so leave all flowers in place.

Water cucumbers daily in warm weather — they need consistently moist (not waterlogged) compost. Grow bags and containers dry out particularly fast. A regular watering routine is more important for cucumbers than almost any other crop.

Feed cucumbers with a balanced liquid feed every two weeks from planting until flowering starts. Once flowers appear, switch to a high-potassium feed (tomato feed or comfrey liquid) weekly. Cucumbers are thirsty as well as hungry — feed into moist soil only, never onto dry roots. Consistent feeding combined with consistent watering gives the best cropping results.

Cucumber plants commonly wilt during the hottest part of the day as a natural protective response — they close their stomata (leaf pores) to reduce moisture loss in extreme heat. If the plant fully recovers by evening once temperatures drop, this is heat stress, not a watering problem. The mistake many growers make is watering heavily in response, which can cause root rot, fungal disease, and compounding problems. Check the soil before watering: if it is still moist from the previous watering, hold off and observe. Only water if the soil is dry and the plant has not recovered by the following morning.