Cucumbers are one of those vegetables that taste so much better when homegrown. So no wonder it’s a favourite with so many British gardeners.
For me, cucumbers are a staple in summer salads, and not just because I love their taste. Cucumbers consist mostly of water, so they help you keep hydrated on hot days.
But they have many other benefits for your health. They are a source of vitamins, especially vitamin K, and minerals, such as copper, magnesium, and potassium. Cucumbers are also low in calories, so can help with weight management too.
These are all reasons why we think every vegetable gardener should grow them. So we put together a list of the most common questions about how to grow cucumbers in the UK and answered them, too.
Are Cucumbers Easy To Grow?
The simple answer is yes. Although they do need to be cared for well. The main factors of growing cucumbers successfully in the UK are:
- Adequate watering – they need a lot of water, but at the same time, overwatering can cause issues
- Good support – cucumber plants grow upwards and need support to prevent them from collapsing
- Warmth – they don’t tolerate cold and can die if exposed to frost
- Transplant shock – cucumbers don’t like to be transplanted, so you need to be careful
While there are a few important things to remember when growing cucumbers, it doesn’t mean they are only for experienced gardeners. I firmly believe that every beginner is capable of growing them in their garden.
All you need is the right information and willingness to put some time and effort in to care for them. Your reward will be tasty and healthy cucumbers straight from your garden to your kitchen.
Can You Grow Cucumbers From Seed?
Yes, you can. In fact, I would recommend it. Not only will you have a much wider choice of cucumber varieties, but you can also ensure that you grow healthy plants that will thrive.
Besides, growing your own vegetables from seed is cheaper than buying plug plants.
One big advantage of growing any vegetable from seed is that you can ensure that they get all they need to grow into healthy, strong plants.
Sowing cucumber seeds is normally done in March if you’re planning to grow them in a greenhouse or polytunnel. If you want to grow them outside, you start sowing in April.
Find out more in our article about growing cucumber plants from seed.
How Often Do You Have To Water Cucumbers In The UK?
Cucumbers are very thirsty plants. That’s not surprising, given that their fruit contains 95% water. So how often do you have to water them?
This will depend on several factors. For one, at what growth stage your cucumber plant is. Small plants, that haven’t started fruiting yet, will need less water. Once the plant starts to produce fruit more water is needed. (Mao et al., 2002)
But the weather conditions also play a part. During hot, dry periods, the cucumber plants will need watering more often, potentially every day. Especially, if you’re growing them under cover, such as a polytunnel or a greenhouse.
The aim is to keep the soil moist at all times, but not wet.
If you do water your cucumber plants, water them from underneath. This will ensure that the foliage doesn’t get wet, and reduces the risk of fungal diseases.
Do Cucumber Plants Need Feeding?
Cucumbers aren’t just thristy, but also hungry plants. They grow best in nutrient rich soil. So the feeding has to start before the plants are in the soil.
Preparing the soil is vital to grow cucumbers successfully. To do this, dig in a good amount of well-rotted organic matter, such as homade compost, in autumn or spring.
If you have a no-dig garden, add at least a 5cm layer of organic matter to your beds. I normally do this in autumn, after the growing season is over. Then in spring, I add a layer of leaf mulch.
With the soil prepared, the cucumber plants will have all they need for the first few weeks. But once they start producing fruit, they benefit from a little bit extra. Feeding them with a liquid fertiliser high in potash, will ensure they produce a good yield.
This one works great, and is one used by many vegetable gardeneres. I have used it myself for years.
- Easy to apply simply mix with water in a watering can according to instructions
- For tomatoes and flowering pot plants
- With seaweed extract for maximum growth and better crops
However, nowadays my favourite liquid fertiliser is the one I get from our wormery. It’s the best liquid feed you can give to your plants. Not only does it contain a whole host of nutrients, but also beneficial microbes that support soil health. (Yatoo et al., 2021)
On top of this, the worms secrete a substance that kills pathogens (bad microorganisms), that could harm your plants. (Alkobaisy et al., 2021) This substance is also found in the liquid feed you get, so even more reason to us it.
In terms of frequency, once a week is generally seen as the right amount to feed cucumber plants.
Do You Need A Greenhouse To Grow Cucumbers In The UK?
No, you can actually grow cucumbers outdoors. While it’s true that cucumbers are warmth loving plants and thive in greenhouses or polytunnels, they can tolerate the lower temperatures of a British summer.
However, not all cucumber varieties will do well outside. So-called outdoor or ridge cucumbers are able to thrive in cooler temperatures. Examples to try grow outdoors include Mini Muncher F1, Vista F1, Gherkins or, Bush Champion.
The outdoor varieties tend to grow thicker, smaller cucumbers. Most also need pollinating in order to produce fruit, as they produce male and female flowers.
While outdoor varieties can tolerate lower temperatures, they are still vulnerable to frost. So it’s important not to plant them out until the risk of frost has past.
How To Grow Cucumbers In The UK Without A Greenhouse?
Whether you grow your cucumber in a greenhouse or polytunnel or outside, the main steps are the same. You can read all about them in my guide about how to grow cucumbers from seed.
However, here are some things you need to be aware of when growing your cucumbers outside:
- Start them off indoors in April
- Don’t plant them outside until the risk of frost has passed
- Harden them off before planting them outside to give them a chance to acclimatise
- Choose a sunny, sheltered position in your garden
- Make sure you water your cucumber regularly, especially during hot, dry periods
If you choose the right variety and keep these factors in mind, you can grow tasty cucumbers outside, even here in the UK.
How Do You Support Cucumber Plants?
Cucumbers come either as bush varieties or climbing varieties. The former needs staking, but not training, as they mostly grow bushy.
The latter will need more support and training. You can use netting, a trellis or, my favourite support structure for cucumbers, a wigwam. To train your cucumber, you attache the main stem to the support.
It should then start to send out shoots that will wrap around the support to hold on to it. I find they sometimes need a bit of help to find the support.
I tend to use the wigwam method for my cucumber plants. All you need is at a least three bamboo canses and some string. Place the canes in a circle aroun the plant, as in the picture above, and tie the canes together at the top.
As the plant grows it will hang on to the canes growing upwards. A single cane will also work, but any side shoots will either have to be caned as well or you need enough space for them to sprawl out.
When Do You Harvest Cucumbers?
This will largely depend on when you have sown them, but also the variety. Generally speaking, you can harvest your cucumbers around 12 weeks after sowing.
Harvesting normally starts in midsummer and can go on until September for plants grown outdoors, and until October if you grow them in a greenhouse or polytunnel.
You don’t want your cucumbers to grow too big, because the older they are they more likely are they to taste bitter and develop tough skin.
Each variety is different when it comes to when to harvest them. My gherkins can be harvested when they are only finger-long, but others will need to be longer. Check your seed packet for specific advice.
While cucumbers can be stored in the fridge for a few days, ideally you want to harvest them just before you need them. This way you get the best flavour.
Can You Grow Cucumbers In Containers?
Yes, you can. So even if you don’t have much space, or only have a mini greenhouse, or even balcony, you can still enjoy the taste of homegrown cucumbers.
Whether you grow your cucumber in a container or not, I would still recommend starting them off indoors in March. Then grow them on until they have two or three true leaves, at which point they can be transplanted into their final pot.
You care for them in the same way as cucumber plants you grow in beds, but here are some important things to keep in mind:
- Choose the right pot – you want a container that is at least 30cm wide and 20cm deep
- Water regularly – plants in pots dry out quicker, so keep an eye on moisture levels
- Provide support – even if you grow cucumbers in pots, you still need to support them
Find out more, including which varieties are best to grow in pots, in our guide about growing cucumbers in containers.
Why Doesn’t My Cucumber Plant Produce Fruit?
This can have several reasons. Let’s check them off one by one…
1. Lack Of Pollinators
The plant might need pollinating but there aren’t enough pollinators. Check your seed packet to find out for sure if you have a variety that needs pollinating. It’s mostly ridge or outdoor cucumbers that need pollinating to produce fruit.
If that’s the case, you need to make sure you attract beneficial insects to your garden, including pollinators. Plant plenty of pollinator friendly flowers in your garden and don’t use pesticdes. It’s also a good idea to put up a bug hotel, that allows different insects, including bees, to shelter and produce young.
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You can also become the pollinator yourself, but you will need two cucumbers of the same variety. You can use thin a brush or q-tip for the purpose. First look for a male flower, which have thin stems.
Dip your brush into the flower and collect the pollen, by gently wiggling the brush. The flowers are very delicate, so be careful. Then look for a female flower on a different plant, which will have a tiny cucumber rather than a stem, and deliver the pollen.
Gently brush the pollen onto the female flower. The pollen of one male flower should be enough for a couple of female flowers. If you do this regularly as soon as any female flower opens, you should get fruits.
2. Not Enough Water
Cucumber plants are sensible to draught, which can cause them to stop producing fruit. So it’s vital that you water them regularly. Especially in a greenhouse, where they don’t benefit from any rain.
I would recommend to water your cucumbere plants every day during hot and dry periods, during particular hot weather potentially even twice a day. In the morning and the evening.
It’s also important to water your cucumber plants at the same time every day, so that the moisture levels stay as even as possible.
3. Lack Of Nutrients
Without the right nutrients, the plants won’t be able to produce fruits. So make sure you feed them once they have started to flower.
A high potsh feed is the best to encourage them to produce fruit.
- Easy to apply simply mix with water in a watering can according to instructions
- For tomatoes and flowering pot plants
- With seaweed extract for maximum growth and better crops
Feeding them with liquid feed once a week as they start flowering will ensure that they have the nutrients they need to grow tasty cucumbers.
What Disases Can Befall Cucumber Plants In The UK?
There aren’t too many diseses that can affect cucumbers in the UK. The most common are:
- Powdery mildew – this fugal disease favours hot weather and mostly affects older plants that come to the end of their cropping period – you’ll see white mould that looks like flour on the leaves
- Downey mildew – this fungal disease will occur in cold, wet weather and cause white/yellowish patches on the leaves (less of a problem when you grow cucumbers in a greenhouse)
- Cucumber mosaic virus – this viral disease is transmitted through aphids and whitefly – the first signs of an infection are yellow patches that look like a mosaic
The best way to stop these diseases from ruining your crop is to prevent them from affecting your plants in the first place. And here are measures you can take to protect your cucumber plants from diseases:
- Water you cucumber plants regular to keep the soil moist but not wet – distressed plants are more likely to be affected by diseases
- Ensure there is good air circulation by spacing your plants out
- Water from below to keep the foliage dry
- Weed the bed regularly to avoid diseases spreading from weeds to your plants
- Practice crop rotation to prevent disease buildup in the soil
- Use companion planting to protect your cucumbers from aphids and whitefly
- Encourgage beneficial insects to your garden to keep pests under control
- Opt for disiease resistent varieties
If a disease strikes, it’s vital to act fast. If you spot any sign of diease:
- Remove the affected leaf/leaves and dispose of them, but not in the compost bin
- Keep an eye on affected plants for more signs
- Severly affected plants won’t produce a good crop, so remove them and dispose of them to stop the disease from spreading to your other veggie plants
What Pests Affect Cucumber Plants?
Growing cucumbers in the UK involves keeping them save from pests. Generally speaking, most pests won’t do much harm and should therefore be tolerated as much as possible. They are part of your garden’s ecosystem and a vital part of the food chain.
Only a heavy infestation could cause real harm. These are the pests that might nibble on your cucumber plants:
- Slugs and snails – they’re only a threat to seedlings and young plants, larger plants can tolerate being nibbled at by these slimy customers
- Aphids – these sap sucking bugs won’t do harm unless you have an infestation
- Whitefly – they are mostly a problem in greenhouses and also suck the sap of plants but won’t do much harm
- Red spider mite – another suck sapping insect that might nibble at cucumber plants in greenhouses and polytunnels
We don’t recommend using pesticides for pest control because we need biodiversity in our gardens for a healthy ecosystem that is necessary to grow healthy plants. There are many other ways to keep pests under control without using harmful chemcials:
- Companion planting can help to repel pests from your veggie plants – aphids and whitefly don’t like the smell of basil, slugs are not keen on the scent of rosemary or thyme, red spider mite aren’t a fan of garlic or onion fragrance
- Let nature control your pests by making your garden a haven for predatory insects such as ladybirds, lacewings and hovereflies – attracting beneficial insects can help keep a balance
- Prevent them from getting to your plants – physical barriers such as insect mesh, or copper rings will keep pests away from your plants
- Pick them off by hand if you aren’t sqeamish – works with aphids and slugs and snails
Now that you have the answers to commonly asked questions about how to grow cucumbers in the UK, why not give it ago. Happy Growing!
