Cucumis sativus, Cucurbitaceae family
From their origins in the Himalayan foothills, cucumbers are now grown and appreciated all over the world. There is a range of cucumber types and this lesson does not comprehensively cover all of them.
I concentrate on what some call the European or English cucumber. They grow best in warmth above about 21 °C/70 °F of an afternoon, and they need support.
Because they are grown vertically, I refer to them here as cordon cucumbers. The fruits have a soft skin and some seeds. They are harvested before the flesh becomes fibrous, when the cucumbers are 30–40 cm/12–16 in long.
Also in this lesson we look at ridge cucumbers. ‘Ridge’ refers to soil ridges on which the plants used to be grown. Their fruits are 12–20/5–8 cm long and often prickly, with a tougher skin compared to cordon cucumbers.
I describe growing them outside, because in climates with summer daytime temperatures above about 18 °C/64 °F this works really well. They can give a large harvest for just the period of high summer, before fading quickly in autumn.
Cucumbers can be sliced and diced for salads, and pickled to eat later. They come in a range of lengths, giving you many choices when choosing seed. The smallest are gherkins – prickly skinned mini cucumbers that pickle well.
- Another variation is fruits of the Mexican sour gherkin which are colloquially called ‘cucamelon’ (Melothria scabra). They are harvested at grape size and look like mini watermelons, hence the name.
I was disappointed when growing them because, from a large and leafy plant, the fruits were hard to find for just a small harvest. The flavour is not as described in the seed catalogue, being more sour than delicious, and fruits are best pickled.
- Something different and highly worthwhile, though not edible, is loofa, ‘vegetable sponge’ (Luffa aegyptiaca).
Grow them in the same way as cordon cucumbers, trained up a string – the photo below gives you an idea of harvest. One plant gave me four loofa of decent size, in the polytunnel. In a temperate climate I would not grow them outside, because they are of subtropical or tropical origin. See this YouTube video: Peeling a loofa.
Harvest period
- Days from seed to first harvest: 60–75.
- Best climate is warm or hot, humid, not too windy.
Why grow them
Feedback from my customers in the local town of Bruton suggests there is little flavour in cucumbers available in most supermarkets. My customers say things like, ‘These cucumbers taste just like they used to!’
Homegrown cucumbers have a fuller and richer flavour, and they are sweeter and juicier from being fresh.
- Plants are just so productive. From one sowing, you can harvest up to 10 kg/22 lb of cucumbers from one ridge plant, over a six to eight week period. While cordon plants crop for over three months, giving 30–40 large cucumbers.
Cucumbers you may be buying
Commercial growing is mass production, of high volumes at low prices. My ‘premium price’ of £1 wholesale for a long cordon cucumber, compares to the standard 70p wholesale price. For a small-scale producer, even £1 for a large and graded fruit barely covers the time needed to grow them, let alone the costs.
- Like most vegetables now, mass-produced cucumbers are grown in soil with not much life.
- Many are not even grown in soil. A common method for under cover production is hydroponic, with roots grown in media such as rock wool.
- Rock wool is manufactured from basalt rock and slag, a waste product from the production of steel and copper.
- A computer-controlled pump pushes water and a programmed, varying collection of nutrients to roots in the rock wool.
If you believe that food is just a collection of nutrients, then you won’t mind eating vegetables grown hydroponically. Many tomatoes are also grown in this way.
However, I suspect that a big deficiency in hydroponic harvests, which has not been mentioned until recently, is of microbes – tiny life organisms that vegetables automatically collect from the soil they grow in. Plus micronutrients and complex organic minerals that we know little or nothing about – partly because science cannot measure them, has not tried to, or does not mention – such as polyphenols and other antioxidants.
- With no dig soil, the count of healthy microbes is increased, which probably affects the flavour as well.
- Having said that, we do not notice consistent differences between flavours of vegetables from my dig and no dig beds. They both receive a decent dose of homemade compost every year!
Pattern of growth
All vegetables of the cucurbit family need a roughly equivalent amount of warmth to grow well. Therefore you can sow seeds of cucumber and squashes at the same time, from mid-spring under cover. Earlier sowings are possible but rarely worthwhile, in my experience.
Cucumbers have an amazing ability to convert warmth and moisture into rapid growth, even at Homeacres where afternoon temperatures outside are usually below 23 °C/73 °F.
- In high summer, cucumber plants make new leaves and fruit very rapidly, from mid-June to mid-August, the two hottest months of summer.
- Then in late summer we see more disease, and growth weakens through autumn until plants are killed by frost or sometimes downy mildew.
- Cordon plants under cover usually crop for a month longer than ridge plants outside.
Male and female flowers, bitterness
38 years ago I grew my first cordon cucumbers in a polytunnel. The variety was Telegraph which is open-pollinated, and grows both male and female flowers. Female flowers grow on the end of baby cucumbers.
Within two months there were some lovely fruits. I picked and ate the first one, feeling so proud, but it was disgusting and I spat it out. I was bitterly disappointed!
It turned out that my market garden mates were growing all-female hybrids (F1). With these varieties, bitterness is not an issue because they have almost no male flowers.
- The easiest way to avoid bitterness is not to grow open-pollinated cordon cucumbers such as Telegraph and Telegraph Improved.
- For ridge cucumbers you do not need to worry about the male flowers – they do not cause bitterness.
It puzzles me that all-female cordon plants do actually have some male flowers, therefore there is some pollination happening. It’s necessary, because without seeds the fruits do not develop correctly.
There are parthenocarpic varieties that do not need pollination, but most F1 hybrids do not fall into that category.
I could find out more by growing a plant of Telegraph again, but cannot discover whether, if I grew it among hybrid cucumbers, it might cause bitterness in them. Do insects fly from its male flowers to the hybrids’ female flowers, and affect flavour? Sorry if I am confusing you, but there is little agreement about the best procedure.
Indigestion
A swollen stomach and wind can happen after eating cucumber – I have suffered this. I eat a lot of cucumber in the warm days of summer, and here is my method for making them more digestible:
- Prepare cucumber two hours before eating – cut off half of the skin or more, slice thinly and sprinkle with salt.
- A lot of liquid drains away.
- This softens and sweetens the cucumber and improves digestion.
Suitable for containers/shade?
Shade is not ideal because cucumber plants thrive in warmth and full light, nonetheless it is possible. Container growing certainly works, as long as you keep up with watering, and to some extent feeding, especially later on. The photos below give an idea of what you can do from one pot.
- Another option is to grow a ridge variety in a large pot, allowing enough space around the pot for the trailing stems and fruits.
Types and varieties
When choosing a variety, be careful that you select the type which is appropriate for your desired growing method.
- You can grow ridge cucumbers under cover, but they would be a lot of work to grow up a string.
- Cordon varieties have mostly been bred to grow in warmth and do not thrive outside.
Cordon vertical growth, under cover
In the UK at least, most current varieties of long, green cordon cucumbers are hybrid, apart from Telegraph.
Hybrid cordons are quicker and easier to grow. Breeding has given us varied fruit sizes, with excellent flavour. There are also lovely heirloom varieties for fruits of a different colour, size and shape.
- Carmen F1 is currently the best hybrid variety for a season-long output of fine cucumbers with top flavour.
- Mini Munch F1 grows fat fruits no longer than 10 cm/4 in – a lot of them.
- Passandra, Petita, Melen and Socrates (all F1) grow half-size, smooth-skinned cordon fruits, say 20 cm/8 in long.
- Burpless Tasty Green F1 grows long cucumbers claimed to be sweeter than other varieties, but I am not convinced about this, good as they are.
- Iznick F1 is something different, a small-fruited variety suitable for growing in a container
Ridge sprawling plants outside
- La Diva F1 cucumbers have an almost smooth skin and plants are prolific. You can also grow them as cordon.
- Tanya has great flavour – fruits are 20 cm/8 in, often with a tapering end and knobbly skin.
- Marketmore (sometimes called Marketmore 76) grows mostly straight fruit of 20 cm/8 in length, with knobbly skin.
Other
- Crystal Lemon grows round, yellow fruits best picked small, say 5 cm/2 in diameter. Crystal Apple is similar. They can be cordon or ridge, more worthwhile as ridge. The terms lemon and apple relate to the fruits’ shape and size, not to their flavour.
- Cornichon de Paris needs picking regularly, when fruits are just 2.5 cm/1 in long. Best grown under cover and can be grown as a cordon.
Clear
This is quick and simple. Use a knife or sharp trowel to cut through the main stem just below where it begins to root into the soil. By season’s end, there has usually been a steady weakening of the lower stems and root structure in the darker and cooler conditions, making them easier to remove.
Take the whole plant to your compost heap and either cut it into pieces or simply squash it down. It’s less important to cut up than, for example, broad beans and tomatoes, whose stems are tougher.
Follow with
Following removal of under cover cucumbers, rake the surface level, water thoroughly, and then all is ready to transplant vegetables for cropping through winter.
Outdoors you may have already interplanted some vegetables. Otherwise you can follow cucumbers with any of spring onions, spring cabbage and garlic.