Cucumbers growing conditions
June 4, 2019
Nurtured in Norfolk’s gardening expert Martyn Davey answers all your questions.
If you would like any horticulture query answered please do e-mail our head grower at firstname.lastname@example.org to add your thoughts to our weekly horticulture hacks.
Could you please give me some advice on how to grow cucumbers. I have for several years grown tomatoes from seed and produced some good crops in my little greenhouse, but find that I have tomatoes when everyone has them and they are to cheap to buy. However cucumbers seem like a better value crop to grow, but do they need the same conditions as tomatoes? Could I even mix them in that same greenhouse?
Home-grown cucumbers taste fabulous. Choose the type that’s right for you – some can be grown outside, some indoors. Outdoor cucumbers can be sown directly into the soil in late May and early June – or you can buy small plants from the garden centre. You can grow cucumbers in the ground, pots or in growing bags.
Growing cucumbers in the greenhouse is quite easy and it is best to start them 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, 1cm deep in pots of seed compost.
Outdoors sow the cucumber seeds 2.5cm 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 warm summers.
Growing indoors is quite easy when the seedlings have grown, transfer young plants to 25cm 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 long.
Keep the humidity high by watering the floor and, once planted out, feed every 10-14 days with a balanced liquid fertiliser.
Cucumbers can be grown directly in the soil prepare the ground by digging in up to two bucketfuls of rotted organic matter, such as garden compost, and rake in 100g per square metre of general purpose fertiliser.
You are best to only grow cucumbers in the greenhouse not mix them with tomatoes as the tomatoes need dry conditions and the cucumbers need the humidity, not least to prevent red spider mite that is a common pest of cucumbers along with whitefly
Cut the fruits when they are about 15-20cm long using a sharp knife.
Select the best varieties of cucumber such as, ‘Carmen’ AGM:Dark-ribbed, well-shaped fruits for growing indoors. All female – remove any male flowers.
‘Femdan’ AGM:Cucumber with dark fruit 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.
Jobs for this week in the garden.
Time to sow tomato and cucumber seeds in a heated greenhouse or warm window sill.
Lift and divide overgrown clumps of perennials they are easy to split and replant for better healthier plants.
Continue to plant deciduous hedging plants, shrubs, trees and climbers particularly urgent for bare root plants.
Martyn Davey – Head Grower