If you haven’t the time or space to sow seed, you will find young cucumber plants in garden centres or perhaps at car boot sales.
Outdoor Varieties
Cucumbers grow best in a soil with a pH of about 6.0. It should be well conditioned with plenty of compost and manure.
In the spring, a propagator will be useful to sow the seed at a temperature of 20 – 21ºC. Place two seeds on their sides in a 3in pot and keep only the strongest seedling after germination. Pot on when large enough using moist potting compost.
After hardening off, plant out in well manured soil in late May or June about 2ft apart. If you prefer to sow the seeds directly, wait until late spring. Warm the soil and protect the seedlings against slugs, by covering with fleece or cloche.
It’s a good idea to keep the fruit away from slugs and save space, so grow cucumbers on a cane wigwam, perhaps in the border. Tie stems to the canes and pinch out the growing tips when they reach the top of the canes.
Indoor Varieties
In late winter or early spring sow seed on their side in 3in pots at a temperature between 21 - 25ºC. In an unheated greenhouse you’ll have to wait until mid-spring. After germination, move into greater light and reduce the ambient temperature. When there are three leaves, move the plant into a larger pot..
Use a grow bag or prepare the greenhouse border with well rotted manure and loam and form into a ridge. When large enough, plant out with the root ball level with the soil surface. Train with wires or canes and nip out the growing tip when they reach the greenhouse roof.
Maintenance
If the indoor variety you are growing has male and female flowers, pinch out the male ones (that do not have cucumbers forming). This isn’t necessary in outdoor varieties.
Feed with a high potash fertilizer when fruit starts to form. Keep watered, don’t let the plants dry out. Pick off any fruit turning yellow and begin regular harvesting in August and September at 6 – 8ins long.
As newer varieties tend to only fruit on the main stem, pinch out lateral branches after the second leaf.
In a greenhouse, cucumbers will suffer from the usual pests i.e. whitefly, red spider mite, aphids. Outdoors you need to look out for slugs and aphids but also cucumber mosaic virus. Leaves become puckered and yellow, and growth becomes stunted. There’s nothing you can do except destroy the plants and protect from aphids that carry the disease.