Komkommer

Cucumis sativus

Engels: Cucumber

vegetableCucurbitaceaeEetbaar

Komkommer (Cucumis sativus) is a edible vegetable from the Cucurbitaceae family that grows up to 200cm tall. This plant thrives in full sun and requires moderate maintenance. Blooms in summer with yellow flowers and attracts bees.

Hoogte

30–200 cm

Breedte

40–80 cm

Zonligging

full sun

Waterbehoefte

high water needs

Grondsoort

loam

Onderhoud

moderate maintenance

Bloeitijd

summer

Bloemkleuren

yellow

Ecologische waarde

Trekt bijen aan

Verzorgingskalender

Taak	Jan	Feb	Mrt	Apr	Mei	Jun	Jul	Aug	Sep	Okt	Nov	Dec
🌱Planten
💧Bemesten
🍎Oogsten

Care tips

Planting

Cucumbers thrive in full sun and need rich, moisture-retentive loam that drains well. They are tender annuals with no frost tolerance, so timing is critical. In temperate Europe, sow seed indoors from mid-April onwards in small pots at 20–25°C, or wait until late May to sow directly outdoors once all risk of frost has passed and soil has warmed to at least 15°C. Cold soil will rot the seed or stunt growth badly. Prepare the planting site by digging in plenty of well-rotted compost or manure a few weeks beforehand—cucumbers are hungry, thirsty plants. If your soil is heavy clay, work in extra organic matter to improve drainage and structure. Sow seed 2 cm deep, on its side to prevent rotting. For transplants raised indoors, harden them off carefully over a week before planting out in late May or early June. Space plants 50 cm apart in rows or blocks, giving trailing types room to sprawl or providing support for climbing varieties. A wigwam of canes, trellis, or netting works well and keeps fruit clean. Plant at the same depth as the rootball—don't bury the stem, which is prone to rot. Water thoroughly after planting and apply a 5 cm layer of organic mulch around the base to conserve moisture and suppress weeds. In cooler springs, consider using cloches or fleece for the first few weeks to maintain warmth. Cucumbers grow rapidly once established, but they need consistent warmth and moisture from the start to succeed.

Pruning

Cucumbers don't require pruning in the traditional sense, but targeted trimming significantly improves yields and plant health, especially for greenhouse or trained varieties. The approach differs depending on whether you're growing ridge (outdoor) or greenhouse types. For greenhouse cucumbers, pinch out the growing tip once the main stem reaches the top of its support, usually around 1.5–2 metres. Remove all side shoots and flowers from the lowest 60 cm of the main stem to direct energy upward. Above that point, pinch out side shoots one leaf beyond the first female flower (the one with a tiny cucumber behind it). Remove any male flowers entirely—pollination causes bitter, swollen fruit in modern all-female greenhouse varieties. Outdoor ridge cucumbers are bushier and need less intervention. Pinch out the main growing tip after five or six leaves to encourage branching and more fruiting side shoots. Remove any yellowing, damaged, or mildewed leaves promptly throughout the growing season to improve air circulation and reduce disease pressure. For both types, check plants every few days during active growth in June, July, and August. Use clean, sharp secateurs or pinch soft growth with your fingers. Always harvest cucumbers while they're still young and firm—leaving over-mature fruit on the plant suppresses further flowering and fruiting. Regular picking is the best way to keep plants productive through late summer and into September.

Maintenance

Cucumbers have high water needs and consistent moisture is non-negotiable for quality fruit. Water deeply at the base every day during hot, dry spells in summer, and every other day in cooler or cloudy weather. Irregular watering causes bitter, misshapen fruit. Avoid wetting the foliage, which encourages powdery mildew—the most common problem with cucumbers in our climate. Mulch helps retain soil moisture and keeps roots cool. Feed generously from May onwards. Apply a high-potassium liquid tomato feed every week once the first flowers appear, continuing through June, July, and into August. Before flowering, a balanced general-purpose fertiliser every fortnight supports strong leafy growth. Cucumbers are heavy feeders and quickly exhaust soil nutrients. Powdery mildew is almost inevitable by late summer. Improve air flow, avoid overhead watering, and remove affected leaves promptly. Slugs and snails target young plants; use barriers or organic pellets. Aphids and red spider mite can be troublesome under glass—spray with soft soap or introduce biological controls. Cucumber mosaic virus, spread by aphids, causes mottled, distorted leaves and stunted fruit; remove infected plants immediately. Cucumbers are frost-tender annuals and will not overwinter. Plants typically collapse with the first autumn frost, usually by late September or October. Clear away all plant debris promptly to prevent disease carry-over. In a good summer with consistent care, a healthy plant will crop heavily for three months, but they demand attention throughout.