
Cucumis sativus
A tender climbing vine grown for its crisp fruits, requiring warm conditions and consistent moisture. In the UK, greenhouse varieties yield earlier and longer, while outdoor ridge types are hardier but need a warm summer.
Step-by-step instructions for growing Cucumber
Change the guide to see different planting timelines and tips.
Grow cucumbers indoors or in a greenhouse for an earlier, longer harvest. Train them vertically and pinch out male flowers to prevent bitter fruit.
Sow seeds on their edge to a depth of in modules or small pots from 31st March - 7th April. Use a heated propagator or warm windowsill at for reliable germination. Do not sow earlier than this window, as seedlings grow quickly and suffer if root-bound.
Once seedlings have two true leaves, pot them on into larger pots from 17th April - 24th April. Handle carefully to avoid damaging the delicate roots, and use a rich potting compost. Keep them in a warm, bright spot to encourage strong growth.
Plant out into greenhouse beds or large containers from 5th May - 12th May. Space plants apart and plant on a slight mound to keep the stem base dry. Provide vertical support like canes or strings for the vines to climb.
Train the main stem up its support and pinch out the growing tip when it reaches the top. Remove male flowers (those without a tiny fruit behind) to prevent bitter fruits, as greenhouse varieties are parthenocarpic and don't need pollination.
Water heavily from the base to keep the soil consistently moist from 8th May, avoiding the main stem and leaves to prevent rot and mildew. Once fruits start to form, feed with a high-potassium liquid fertiliser every 14 days to support fruiting.
Harvest fruits frequently while they are small and firm from 22nd June - 15th October. Use a sharp knife to cut them from the vine, picking every few days to encourage more production. Regular harvesting prevents fruits becoming oversized and bitter.
Plants that grow well (or poorly) with Cucumber
Companion planting can help deter pests, improve pollination, enhance growth, and maximize garden space. Some plants release chemicals that repel pests or attract beneficial insects, while others can improve soil quality or provide shade for sensitive plants.
Popular varieties of Cucumber to consider
A reliable outdoor ridge cucumber with good disease resistance, producing dark green fruits ideal for slicing.
A popular greenhouse variety that is parthenocarpic, yielding long, smooth fruits without pollination.
An heirloom outdoor type with round, pale yellow fruits and a mild flavour, suitable for cooler summers.