The Vegetable Garden

How To Grow Cucumbers From Seed

How To Grow Cucumbers From Seed
The best cucumbers are those grown indoors - and of course, they crop earlier. However, they do need a fair bit of care and attention, which makes outdoor growing an easier proposition.

Different varieties are required for either indoor or outside culture. Wherever possible, select all-female, F1 varieties for indoor use as these don't, under good growing conditions, produce male flowers - just the cucumber-producing female flowers. If male flowers are produced (they just have a stem behind the flower, not a young cucumber), they should be removed otherwise the flowers will be pollinated and the fruit will taste bitter.

Sowing
Sow the seeds on their side a half-inch (13mm) deep when sowing indoors or one inch (2.5cm) deep if sowing direct outside. Sow at a constant 75-80°F (24-27°C). Maintain a temperature of 65-70°F (18-21°C) after germination and when growing on. Greenhouse cultivation: sow from mid-February to mid-March (heated greenhouse) or April (unheated greenhouse). Outdoor cultivation: sow in late April. Alternatively, sow directly outside in late May or early June and cover the soil above the seeds with a cloche or glass jar; this method isn't always successful.

Growing
Transfer plants to 10in (25cm) pots of good compost in late March (heated greenhouse), late May (unheated greenhouse) or early June outdoors. Keep the compost evenly moist - little and often is the best way.

For outdoor growing, make planting pockets 18in (45cm) apart two weeks before seed sowing or planting out that are 30cm (12in) square and deep and fill with a mixture of compost or well-rotted manure and soil. Leave a low mound at the top of the planting medium. Sprinkle a general fertiliser over the soil. Feed plants every 10-14 days once planted out with a balanced liquid fertiliser, changing to a high potash one once the first fruits start to set. Indoor Keep the humidity high by watering the floor. Train the main stem up a vertical wire or cane. Pinch out the growing point when it reaches the roof. Pinch out the tips of side shoots two leaves beyond a female flower. Pinch out the tips of flowerless side shoots once they reach 2ft (60cm) long. Outdoor Pinch out the growing tip when the plants have developed seven leaves. The developing side shoots can be left to trail over the ground or trained up stout netting. Pinch out the tips of flowerless side shoots after seven leaves. Don't remove the male flowers. Keep the soil constantly moist by watering around the plants not over them.

Harvesting
Cut the fruits when they are about 6-8in (15-20cm) long using a sharp knife.

Pim Dickson

Plant Expert

When Pim joined D.T. Brown, it was originally as a seed buyer, but now as our planting & sowing expert, he’s responsible for all horticultural and technical content, sharing his expertise in this catalogue, and through the growing advice and tips on our seed packets.

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