How to Grow Cucumbers

Cucumbers are a member of the Cucurbit family and are related to pumpkins, squash, zucchini and melons. As such they can be grown together in the vegetable garden. They are a warm season vegetable crop and as such in cooler climates can only be planted in mid spring when temperatures are over 15 deg c. If grown at ground level, space them about 1 mtr apart to allow for some minor spreading, or, like I do, plant and train up a small trellis. This takes up much less room in the vegetable garden bed or pot, keeps the fuit out of the soil and enables you to plant closer together at around 50cm apart. They are more sensitive to acidity in the soil than other cucurbits, so take care and check the soil ph doesn't go below 6.5. 

Growing Conditions


Position: Full Sun, protected from strong winds


Plant: Sow direct in Spring when soil temperatures have started to warm, or in punnets in a greenhouse. Keep seed moist but not wet, otherwise they will rot. Plant out as seedlings after the last frosts.


Frost Tolerant: No. Heat tolerant:  Yes, but extreme heat can cause burning.


Feeding: Cucumbers love lots of organic matter in the soil, more than any other cucurbit so make sure the bed is well composted before planting. Liquid feed every two weeks from mid summer. Water/feed at soil level only.


Planting group: Cucurbits, plant with other cucurbits and sweetcorn


Pests: Birds, snails and slugs as seedlings. There are not a lot of crawling pests to worry about when it comes to Cucumbers and other cucurbits, especially if the fruit is kept off the soil. The big enemy here is mould or mildew. All cucurbits are particularly susceptible to powdery and downy mildew as well as nematodes. The mildews can be reduced by ensuring that there is plenty of airflow around the plants (so don't overcrowd them), by planting them in good sunny positions and ensuring you don't water them from above. This causes an increase in humidity and that is just what the mildews love.


Harvesting: This depends on the variety. Generally size is the main indication. If left too long, fruit will start to yellow. If grown too large, excess seeds will be encountered.



General Care


Other than suffering from powdery mildew in higher humidity areas, the Cucurbit family is fairly tough.


This however caught me by surprise. This Cucumber seedling had already been hardened off before transplanting, yet an unexpected burst of Summer, whilst still in Spring, resulted in this sunburn on the stem of this plant.


Until well established, covering with some sort of shade cloth is the only real solution.



Cucumbers produce male and female flowers and most varieties need each to produce fruit. The flower sex is determined by the number of daylight hours, with more female flowers produced in the shorter periods. If you live in a cooler climate, you probably won't have an issue, as by the time it is warm enough to grow these, the fruiting will be occurring after the summer solstice. The further north (or south if you're in the Northern Hemisphere) you go, the longer the days will be and the less fruit produced if you don't swap varieties. Some varieties produce fruit parthenocarpically (no need for flowers to be pollinated) so are suited to greenhouse growing in cooler climates if required as they won't need bees to pollinate the flowers. This may also help counteract the problem of limited female/male flower ratio in those long summer days.