Cucumbers can be grown in the greenhouse or outdoors. The outdoor cucumber was often regarded as inferior to it's greenhouse equivalent but this is not so much the case these days, with better choices of outdoor varieties. The advantage of greenhouse growing is that the fruit is ready in May or June while you will have to wait until the summer for outdoor cropping. Modern all-female varieties have overtaken other types in popularity as they only produce female flowers so you do not have the chore of removing the male flowers.
Soil & Growing Position
Plant in growbags, 10" pots filled with John Innes No. 3 or outside in the open ground in fertile and free-draining soil, in a warm and sunny position protected from strong winds. Outdoor cucumbers grown in the open ground are planted into planting pockets rather than rows as only a few plants are usually needed. Prepare planting pockets a couple of weeks before planting or sowing by digging 2 or 3 holes 18" apart, 12" deep, 12" wide, refilling with a mix of compost and soil and sprinkle a general fertilizer over the top. Place a cloche over the planting pockets for a week or so prior to planting to warm the soil.
Sowing from Seed
Use 3" peat pots filled with seed compost and sow one seed edgeways at a half inch depth per pot. Seedlings will need to be raised under glass at a temperature of 21 - 27 degrees. Sow in late February/early March for heated greenhouse growing and late April for an unheated greenhouse or outdoors. Alternatively, seed can be sown directly outdoors in late May or early June. Sow into planting pockets (as described above), 3 seeds a few inches apart in the centre of the pocket at a depth of 1" and cover with a cloche for several weeks.
Growing On & Young Plants
Outdoor cucumbers should be thinned to the one strongest plant per pocket once the first true leaves have appeared. If you have started off the seeds under glass for outdoor cultivation, gradually harden off the plants once they are established by placing in a coldframe or cold porch for a few days before planting out in the pockets in early June. Take care not to disturb the roots when transplanting and water in throughly.
Greenhouse cucumbers will need to have their stems trained up a cane. Once this reaches the roof, the growing tip can be pinched out. The sideshoots also have their tips removed at two leaves beyond a female flower. Flowerless sideshoots have their tips pinched out when they are 24" long. Female flowers have a tiny cucmber behind the flower while the male flowers have a thin stalk. All-Female varities will not need any flowers removing but Ordinary greenhouse varieties will need the male flower removing as fertilised fruit tastes bitter.
With outdoor cucumbers, the growing tip can be pinched out when the plant has developed 6 - 7 leaves. Side shoots that develop can be left to trail over the ground and shoots that have no flowers should be pinched out at the seventh leaf. Do not remove the male flowers from outdoor varieties.
Crop Care
Greenhouse cucumbers will need good ventilation and consistantly moist compost but not waterlogged. They also need a good level of humidity so mist regualrly or in warm weather, water the floor and the evaporating water will increase the humidity. Outdoor cucumbers should be watered around the plants but not on them. Laying weed control membrane around the plants helps to warm the soil, conserve moisture, keeps the weed down and also keeps the fruit off the ground, helping to prevent rot.
Use a high potash feed such as Tomorite once the fruit appears.
Harvesting
Harvesting begins in June for greenhouse crops, continuing up to mid October. Outdoor crops begin in late July and continues up to the end of September.
Start cutting when the fruit is of a reasonable size, around 6 - 8" and pick continuously to encourage further fruiting. Do not wait for them to become massive, cropping will cease if fruits are allowed to mature/turn yellow on the plant. Pick cucumbers by cutting with a sharp knife, do not tug or pull the plants.
