Introduction

Cucumbers (Cucumis sativus) are trailing annual plants that can grow to 1-3m (3-10ft). There are also a few bush cultivars. The fruits are eaten raw, pickled or cooked. Cucumbers tend to be long and green but length depends on the cultivar, weather and when you harvest them. Cucumbers are warm season crops, with no tolerance to frost. They must have temperatures of between 18C and 27C (64-81F). They require no added nitrogen fertiliser, as this will encourage lots of leaf growth and little fruit.

How to Sow for Best Results

Cucumbers transplant badly so ideally sow in situ from late May, when all risk of frost has passed and the soil temperature is at least 16C (61F). Prepare holes at least 30cm (12in) wide and mix in plenty of well rotted garden compost or farmyard manure. Mound the planting hole up slightly as this will help with the plants' drainage. When planting the seed, place them on their side about 2.5cm (1in) deep. Sow two or three seeds per mound, and after the seeds have germinated remove the weakest plants, to leave the strongest. Climbing or trailing types (e.g. Burpless Tasty Green or Jazzer) should be spaced about 45cm (18in) apart and the bush forms (e.g. Aidas or Carmen) about 75m (30m) apart. In cold areas protect the young plants and seedlings with floating mulches or cloches. A thick mulch should also be applied to help retain water and increase the general soil and atmospheric conditions around the plant.

From January to April, they can be started off in 7.5cm (3in) pots, and grown indoors, but as they transplant badly the in situ method is preferred. Place two or three seeds, on their sides, about 2.5cm (1in) deep per pot, which is filled with moist compost.

The compost should be moist, but definitely not wet. Wet compost (which can even be the case straight from the bag) will be cold and reduces the oxygen that the seeds need to germinate. It may even stop the seeds germinating at all. If the compost is too dry this will also cause problems. If this is the case, sprinkle a small amount of warm, clean tap water over the compost and leave it to soak in thoroughly. When the compost has absorbed the water, take a small handful and squeeze it in your fist. If water drips out it is too wet, so leave it for a short while in a well ventilated spot to dry off. If it holds together when you open your hand, it's just about right. You can now fill your pot with the moist compost and you don't have to water it again before you sow the seed. Regularly check the compost for dryness. If this is the case, add a little clean water from below, being careful not to over water. Too much water can kill seedlings, as it can spread "damping off fungi" and encourage other moulds and diseases.

After they have germinated thin out the seedlings to remove the weakest, leaving the strongest. Seeds germinate best if kept at 20C (68F). The night temperature should be no lower than 16C (60F). This night temperature should be maintained for four to six weeks after the seedlings have been planted out, (follow in situ instruction after planting out). Therefore harden off and plant out when all frost has passed and use cloches or floating mulches to help keep the temperature up.

Trailing types may be grown up canes or fences, they can also be allowed to twine up strings. Nip out the growing point when the plants have about five leaves. This will encourage a stronger growth. Train up the supports tying in as required. When the plant has reached the top of the support, nip out the tip, two leaves beyond the last flower. Side shoots will then develop, producing more flower and fruit.

Greenhouse or plants grown in cold frames are grown the same as outdoor types. The best forms are the all female ones. Stop the plants again when they reach the top of the support or it allowed to trail on the ground nip out the main shoot when it has produced about 1.5m (54in) of growth and remove side shoots after one leaf. Keep the greenhouse damped down to reduce any pests.

All female types may produce male flowers if they are grown under stressful conditions. These flowers should be removed.

Water regularly and feed with a high potash liquid feed every two weeks. Keep an eye out for slugs and snails, especially when the plants are young. If they become a problem, use a recommended proprietary brand of slug and snail bait. Try to avoid watering from above as this may lead to a fungal problem especially in warm weather. Pick off any badly affected leaves and spray with a recommended proprietary brand of fungicide.

Harvesting Your Crop

Cut cucumbers regularly from about twelve weeks after planting. The sides of the fruit should be parallel and about 12-15cm (6-8in) long (depending on the variety). Always handle with care as they can bruise. Cut them with a short stem and check the plant regularly for fruit. Regular cutting will produce more fruit.

Flower and therefore fruit development is sometimes a little erratic at the start of the season. Generally the first flush of flowers will be mainly female. Female flowers have a small swelling (embryonic fruit) behind the petals. Most pollination is done by insects, but if fruit is failing to set, the female flowers can pollinated by hand.

To pollinate by hand, take a male flower and remove all its petals and press it against the centre of the female flower. Pollen can also be transferred using a fine paint brush, taking pollen from the male stamen and brushing it lightly over the female stigma.

Cucumbers generally don't store for very long unless pickled, so cut and use the fruit while fresh.