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Growing cucumbers

Cucumis sativus. A summer vine grown for its crisp young fruit, sown where it grows or raised in small pots, and usually trained up a trellis. It wants sun, warmth and steady water, crops for weeks if picked often, and frost kills it. These steps work anywhere: they go by soil and weather, not by month. Also called gherkin (for small ones picked to pickle).

How a cucumber grows

1. 
   SowA few seeds, on their sideUp in 1–2 weeks
2. 
   ThinKeep the strongest twoAbout 2 weeks
3. 
   ClimbTie in, pinch side shoots4–6 weeks
4. 
   FlowerMale flowers open firstAbout 6 weeks
5. 
   PollinateFemales have a tiny fruit behindA week or two later
6. 
   SwellYoung fruit lengthen fastA few days after flowering
7. 
   PickCut while young and firmFrom about 8–10 weeks
8. 
   Keep pickingEvery few days, for weeksUntil the weather cools

Times run from sowing in the bed and vary with the variety and the weather. Seedlings raised in pots go out at 3–4 weeks old and start cropping about 6 weeks after planting.

Growing it, step by step

1. Is it right for you?

   • Cucumbers need about two months of warm, frost-free weather to start cropping, with days around 18–29°C (65–85°F), and they keep going while it stays warm.
   • Frost kills them, and cold nights below about 10°C (50°F) can damage the leaves, worst on young plants. Cool, cloudy weather keeps bees away, so fruit comes crooked or not at all. Very hot spells bring more male flowers and fewer fruit.
   • Climbing kinds grown up a trellis take little ground, and one or two plants per person are plenty for salads; grow more to pickle. Compact bush kinds grow in a pot at least 30 cm (12 in) wide and deep.

2. When to plant

   Sow where they are to grow once the soil is at least 16°C (60°F) and the last frost has passed. Seed comes up slowly in cool soil: nearer 21°C (70°F) is better. For an earlier start, sow in small pots indoors three to four weeks before you plan to plant out, kept warm at about 21°C (70°F), and plant out after the last frost.

   Short, cool summers: start seeds in pots indoors, plant out after the last frost and cover young plants with fleece, or grow them in a greenhouse. Mild climates: sow from late spring; a second sowing about a month later keeps the harvest going. Hot or subtropical places: sow in spring and again in late summer, and give light afternoon shade in the hottest weeks. Tropics: the cooler, drier months, on mounds or raised beds so the roots drain.

3. Prepare the bed

   • A warm, sunny, sheltered spot. Put up a trellis or netting about 1.5 m (5 ft) tall before you sow or plant, so you don't disturb the roots later.
   • Dig plenty of compost or well-rotted manure into each planting spot a few weeks before sowing.
   • Cucumbers need good drainage. Where the soil stays wet, sow or plant on a low mound or in a raised bed.
   • Slightly acid soil suits them best, pH 6.0–6.5, but most garden soils grow them well. See soil pH.
   • Avoid beds that grew cucumbers, zucchini, pumpkins or melons in the last two to three years. They share the same pests and diseases.

4. Sow and plant

   • Sow three or four seeds 1–2.5 cm (½–1 in) deep in each spot where plants are to grow. Lay the flat seeds on their side.
   • Or sow one seed on its side 1–2 cm (½–¾ in) deep in a small pot, about 10 cm (4 in) across, and keep it warm.
   • A week or so before planting out, harden seedlings off: put them outside by day and bring them in at night. Plant them at 3–4 weeks old, at the same depth as in the pot, without disturbing the roots.
   • Space the spots 40 cm (16 in) apart along the support, in rows 1 m (40 in) apart. Left to sprawl on the ground, they need about twice the room.

5. Get it started

   • Water well after sowing, then keep the soil just moist, not wet, until the seedlings are up. Cucumber seed won't come up in cold soil.
   • Water seedlings you plant out every day for the first week, until they settle.
   • About two weeks after sowing, keep the strongest two seedlings in each spot and snip the others off at soil level. Pulling them disturbs the roots of the ones you keep.
   • Protect young plants from slugs and snails, and cover them with fleece on cold nights. Take covers off once the flowers open, so bees can reach them.

6. Keep it growing

   • Tie in and pinch: as the vines grow, tie the stems loosely to the support each week and guide them up it. Pinch out the tip of any side shoot that has seven leaves but no flowers.
   • Water: a deep soak at the base about three times a week, more often in hot weather and once fruit forms, best in the morning. Keeping the leaves dry helps against downy mildew and other leaf diseases. Dry spells make the fruit bitter or misshapen. Pots may need water every day in hot weather.
   • Mulch: about two weeks after planting, once the soil is warm, spread compost or straw about 5 cm (2 in) deep to hold moisture and keep the fruit clean. Keep it off the stem.
   • Feed: good soil needs little or nothing. On poor soil, a high-potash liquid feed every two weeks once flowering starts; in pots, a liquid feed every 10–14 days, high-potash once the flowers come. Too much nitrogen grows vine instead of fruit.
   • Fruit set: the first 10–20 flowers are male and drop off, which is normal. Leave the male flowers on: the female flowers, with a tiny cucumber behind them, need their pollen. If baby fruits shrivel or grow crooked (poor fruit set), hand-pollinate in the morning: dab pollen from a male flower into an open female flower with a soft brush, or with the male flower itself, its petals pulled off. Greenhouse kinds are mostly all-female and set fruit without pollen: on those, pick off any male flowers, as pollinated fruit can taste bitter.

7. Watch for problems

   The common ones, with a Garden help page each where there is one:

   Powdery mildewDowny mildewMosaic virusAnthracnoseAngular leaf spotBacterial wiltCucumber beetlesAphidsSpider mitesWhiteflySlugs and snailsPoor fruit setBitter fruitCold damage

8. Harvest

   • Pick while young and firm, before the seeds harden or the skin turns yellow: small pickling kinds at 5–10 cm (2–4 in), slicing kinds at 15–20 cm (6–8 in), round apple kinds at about the size of a tennis ball.
   • Cut the stalk with a knife, scissors or secateurs rather than pulling: pulling can break the vine.
   • Check every two or three days once they start: they grow fast. Fruit left to grow big and yellow slows the plant.

9. After harvest

   • Keep them in a bag in the fridge and use them within about a week.
   • Bitterness usually sits at the stalk end and just under the skin: cut off the end and peel. Throw away any that still taste bitter.
   • Pull the plants out when they stop cropping or the weather turns cold. Bin plants with mosaic virus rather than composting them.
   • Next in that bed: a cool-season crop such as peas, broad beans, garlic or leafy greens. Keep cucumbers, zucchini, pumpkins and melons out for two to three years.

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Sources

• RHS: How to grow cucumbers
• Clemson Cooperative Extension: Cucumber
• Iowa State University Extension: Growing cucumbers in the home garden
• Sustainable Gardening Australia: Cucumbers
• Northern Territory Government: Growing cucumbers in the Top End

Facts checked Wednesday 21 October 2026. General guidance only: local advice comes first.