Growing in the greenhouse
Start cucumbers off by sowing seeds from mid-February to mid-March if you have a heated greenhouse or similar environment, or in April if you have an unheated greenhouse. Sow seeds on their side, 13mm (1/2in) deep in pots.
Sow seeds 2.5cm (1in) deep indoors in late April. Alternatively, sow directly outside in late May or early June and cover the soil above the seeds with fleece, a cloche or glass jar. This method can work well in southern regions and in warm summers.
Young plants are also available from garden centres in spring.
Transfer young plants to 25cm (10in) pots of good potting compost in late March (heated greenhouse), late May (unheated greenhouse). Keep the compost evenly moist – little and often is the best way. You can also use growing-bags but plants will need to be carefully watered and looked after.
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 sideshoots two leaves beyond a female flower (recognisable by tiny fruits behind flower). Pinch out the tips of flowerless sideshoots once they reach 60cm (2ft) long.
Keep the humidity high by watering the floor and, once planted out, feed every 10-14 days with a balanced liquid fertiliser.
Either sow seeds or plant out young plants in early June, ideally under fleece or cloches. Any fertile garden soil in full sun is satisfactory.
Dig in up to two bucketfuls of rotted organic matter, such as garden compost, and rake in 100g per square metre (31/2oz per 103/4sq ft) of general purpose fertiliser.
Pinch out the growing tip when the plants have developed seven leaves. The developing sideshoots can be left to trail over the ground or trained up stout netting. Pinch out the tips of flowerless sideshoots after seven leaves.
Don't remove the male flowers, and keep the soil constantly moist by watering around the plants – not over them.
Cut the fruits when they are about 15-20cm (6-8in) long using a sharp knife.
When growing indoors always select F1 cultivars as these don't, under good growing conditions, produce male flowers – these need pinching out regularly otherwise the female flowers will be pollinated and the fruit will taste bitter.
‘Femdan’ AGM: Cucumber with dark fruit for growing indoors. All female - remove any male flowers.
‘Carmen’ AGM: Dark-ribbed, well-shaped fruits for growing indoors. All female - remove any male flowers.
‘Marketmore’ AGM: Ridge cucumber with trailing habit; yields well outdoors. Do not remove male flower. Good yield of short, attractive, dark fruits.
‘Tokyo Slicer’ AGM: High yielding, outdoor variety with long smooth fruits. Do not remove male flowers. F1 hybrid; long, smooth-skinned, dark slightly ribbed fruits.
‘Zeina’ AGM: Very high yield of short fruits on strong plants best suited to indoor use. All female - remove any male flowers.
Find out more information on the latest AGM plants
Whitefly: This tiny sap-sucking insect will fly up when the leaves are disturbed. It creates a sticky substance, known as honeydew, which acts as a host to sooty mould.
Remedy: Sprays containing fatty acids are effective both indoors and outdoors. Under glass, use a biological control – Encarsia formosa is a tiny parasitic wasp that controls the pest. Alternatively use a suitable pesticide.
Find out more about whitefly
Cucumber mosaic virus: Plants and leaves are stunted and deformed, and leaves show distinctive yellow mosaic patterning. Flowering is reduced or non-existent, while any fruit that do appear are small, pitted, hard and inedible.
Remedy: The disease is spread from plant to plant by sap-sucking aphids, so take any necessary measures to control them. Infected plants should be destroyed – wash your hands after touching infected material to avoid contaminating healthy plants.
Find out more about cucumber mosaic virus
Read more information on aphids
Powdery mildew: A white, powdery fungal growth occurs on the upper leaf surface and often spreads to the underside. It is most often a problem where soil is dry but the air around plants humid and stagnant.
Remedy: Ensure healthy growing conditions. Keep plants adequately watered, but avoid overhead watering. Remove affected leaves promptly. Dusting with sulphur and fish oil fungicides can be used.
Find out more about powdery mildew