How to grow cucumbers

Learn how to grow cucumbers in your garden with our simple step-by-step guide

How to grow cucumbers
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If you learn how to grow cucumbers in your garden, you'll have a steady supply of this staple salad ingredient. Cucumbers are simple to grow and don't need much space, meaning they're the perfect option if you only have room for containers or growing bags. 

The most important thing when growing cucumbers is to consider which type is right for your garden: some varieties are grown indoors in a greenhouse and some are grown outdoors, so choose the right one for you. Cucumber seeds are usually sown between February and June and are ready to harvest from July through to October.

Keep reading for our step-by-step guide to growing cucumbers, from how long it'll take to grow, to the common problems and how to avoid them. If you fancy growing more of your own salad ingredients, take a look at our guides to growing tomatoes and nurturing lettuce during winter.

Step-by-step guide to growing cucumbers indoors

Method:

1. If you have a heated greenhouse, sow seeds from mid-February to mid-March. If you don't, wait until April. Sow seeds on their sides, 1cm deep.

2. Move your young plants to 25cm pots in late March if you have a heat greenhouse or late May if unheated. Water little and often

3. You'll need to train the main stem of your cucumber plants up a wire or cane. Pinch out the tallest stem when it reaches the roof. 

4. You'll also need to pinch out the tips of side shoots. Where you see tiny fruits behind a flower, pinch leave two more leaves and then pinch out. Pinch out flowerless stems at 60cm long.

5. Keep the humidity high and feed every two weeks with a balanced liquid fertiliser.

Step-by-step guide to growing cucumbers outside

1. You can sow your cucumber seeds indoors in late April or wait and sow them directly outside in late May to early June. Sow the seeds 2.5cm and, if planing directly outside, cover with fleece or a glass jar.

2. Before planting or moving outside, dig through well-rotted organic matter and a general purpose fertiliser. Try to choose a sunny spot.

3. If you started your seeds indoors, move them outdoors in early June. You can also buy young plant from garden centres and place straight outside. Try and choose a sunny spot.

4. Pinch out the growing tip when the plants have seven leaves. Sideshoots can be left to trail over the ground and pinched out when they have seven leaves if they have no flowers on.

5. Keep the soil moist by watering around the plants, not directly over them.

The best places to buy cucumber seeds online

When are cucumbers ready to pick?

Cut the fruits – yep, they count as a fruit – with a sharp knife when they are about 15-20cm long.

How to grow cucumber

(Image credit: Getty Images)

Varieties of cucumber to try

  • ‘Marketmore’ AGM –  grows well outdoors with lots of short, dark fruit
  • ‘Zeina’ AGM –  lots of fruit, best grown indoors
  • ‘Tokyo Slicer’ AGM –  easy to grow outdoors, with long, smooth fruits

Common problems when growing cucumbers

According to the RHS, whitefly and cucumber mosaic virus are the biggest threats to your cucumber crop. Whitefly secrete a sticky substance onto cucumbers which encourages mould to grow. Use a chemical whitefly killer outdoors or hang sticky traps in your greenhouse. 

Cucumber mosaic virus causes the plants to be deformed and the leaves show a yellow mosaic pattern. Destroy any infected plants and use a spray made of water and detergent to discourage aphids, which spread the virus.

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