There are two kinds of cucumbers; one needs a trellis or something to climb. The other does not. Bush cucumbers grow in that shape and these are happy without a trellis. If however, you have a vine cucumber then a trellis or climbing frame of some sort is essential.
Read on to learn which trellis is good for cucumbers, how to train your cucumber on a trellis and what types of trellis might suit your pot or garden.
Do cucumbers need a trellis?
As the cucumber plant grows, its large leaves need support and its little tendrils try to catch on to anything close by, to enable this plant to grow towards the light. Sunshine is the cucumber’s best friend and so it climbs higher and higher to reach it.
Cucumbers are annual plants, which mean you need to grow new plants each year from seed. Gorgeous bright yellow flowers form on the stems of both bush and vine cucumbers, which are then fertilized by bees and pollinators (or you with a paintbrush! see below…) to become cucumbers.
A trellis supports the growing fruit and also allows good ventilation, which helps to avoid some of the common problems that affect cucumbers. Read on to see how your trellis will help you to produce tasty fruit.
Which types of trellis will support my cucumber?
Three types of trellis will support cucumber plants: in a pot, in a greenhouse and in the soil.
1. Growing cucumbers indoors
The cucumber in a pot needs a lot of nourishment so ensure that your trellis is in place before you plant in your cucumber. This is because you might damage the roots if you stick in trellis, canes or supports after planting.
Some of the best trellis for cucumbers include:
- Bamboo canes and string. Place 2-3 canes in the pot and tie string around these about a foot from the base. Leave the strings so that when the cucumber grows, you can secure the stem with these. As the plant grows, wind the tiny tendrils that form around the bamboo or the string. Try to buy a natural string (not plastic types) if you can – cucumbers prefer natural products in my experience. When a cucumber is forming, you can make a string support to rest it on.
- Pruned branches from other garden plants. Select the branches and cut off any odd twigs. Then place these in your pot and tie them in with string as described above. These make quirky trellis that delights the eye with yellow flowers poking through the branches. You can use the branches as support for the growing cucumbers. Sometimes you can fool visitors into thinking you’re growing special plants because the support is so obviously not a cucumber!
- Specially purchased obelisks. In most garden centres you can buy obelisks and other supports which your cucumber will happily climb. The only word of caution here is that frequently, your cucumber has its eyes on the sky and the obelisk may not be tall enough. So choose the tallest you can buy.
- Other tall plants close by. Cucumbers are remarkable at finding any support on which they can climb, so if you have a sunflower next to the pot, you may find that your cucumber spreads to attach its little tendrils to the stem or leaves.
2. Growing cucumbers in a greenhouse
In a greenhouse, your cucumber has found an ideal spot. Providing that you give it enough nutrition through the soil, this plant gets an early start inside so that your plants can be climbing just after the risk of frost has passed.
Plant your seeds sideways in the soil and water well. I usually add 2 or 3 sticks for them to climb but also to remember where I planted them! They like a sunny location.
Some greenhouses come with tables or supports. If this is the case you can plant your seeds so that they can climb the support available. I like to take out all the tables because cucumbers will fill your entire greenhouse by the end of the summer and just add a bamboo or pruned branch as the first support for my plant.
Watering indoor cucumbers is essential and the best method is to set up an automatic watering system twice a day to do this for you. If you are using a watering can try to avoid getting moisture on the leaves. They don’t like it much. Cucumbers need a lot of water – see more below.
Some greenhouse pests include red spider mites, aphids and mealybugs. Keep reading to learn how to deal with these below.
3. Is your cucumber plant growing outside?
Remember that cucumbers aren’t frost hardy so only plant your cucumber in the ground after all risk of frost has passed. You can speed up the process by sowing your seeds indoors. Place the pot on a sunny windowsill and transplant them outside after the warm weather arrives.
Outdoor cucumbers are usually smaller in size than greenhouse cucumbers and they like to sprawl all over the ground, if not supported on a trellis. The benefit of growing cucumbers vertically by trellis is that it allows a lot more air to circulate among the leaves and the developing fruit, so this makes the plant less likely to become diseased or get eaten by slugs and snails.
Choose a sunny location where direct sunlight will nourish the plant for as many hours a day as possible. Cucumbers love the sun!
Prepare the ground well and dig out any perennial weeds such as bindweed or dandelions. Then dig in some well-rotted manure if you have any or add shop-bought or homemade compost. Cucumbers are hungry plants and need a lot of nutrition so give them lots of energy from the beginning.
Next, think about supporting your cucumbers as they grow, Pallets can make great supports for cucumbers but snails and slugs can hide easily inside the planks so inspect these carefully and remove any intruders.
An existing fence is a great alternative to pallets, bamboo or sticks but you may need to add a few nails so that you can tie in the stem, flowers and developing fruit as your plant stretches its way upwards.
How to make cucumbers climb a trellis?
To trellis cucumbers, you need to get some string in place to gently support the stem as soon as the seedling leaves of the plant appear, and when your seedling has at least 6 leaves, then tie them in carefully to the support. Do not tie very tightly because the plant stem will continue to expand and this will feel like a tight belt after a big dinner! Tie it loosely, allowing for growth. Let the stem continue to grow and use the string simply as a guideline for the plant.
If you have several plants in a row, you can tie some string horizontally joining all the plants and then your plants will happily spread sideways, attaching to the closest string they find. This method also uses up any leftover string that comes on parcels or DIY projects.
The string support is really useful when small fruit starts to develop. Now you can add extra string to support the actual cucumber as it grows. Allow the fruit to rest on the string and as it grows, you can tie in another sting if required.
How do I pollinate a female cucumber flower?
Sometimes the cucumber plant refuses to fruit. If this is the case for your plant, take a good look at the flowers.
Most modern varieties are all-female but the original plants used to have both male and female flowers, and for pollination to occur, the pollen from the male must touch that of the female.
The female flowers seem to have a little rounded fruit already behind the flower whereas the male flower has a longer creamy extension in the centre. You need to paint the male flower with a brush to remove some pollen, and then paint the female with this pollen, and hey presto! A cucumber should result.
Do remember to remove the male flowers after you pollinate or your cucumbers may be bitter and not as tasty as you hoped.
Why do I have so few cucumbers?
As the very first fruits appear, pick them quite small. This will encourage your plants to keep growing. Otherwise, they may try to go to seed really early, putting all their strength in the first 2-3 fruits.
Should I fertilize my cucumber plants?
Definitely! Your plants need regular feeding at least once a week when they are fruiting or you will be disappointed by the size of your crop. You can use:
- Tomato feed diluted with water
- Home-made feed e.g. nettles, dandelions or comfrey leaves soaked in water for 3-5 days, then added to your watering can is excellent for cucumbers.
How should I water my plants?
Cucumbers need a lot of water but remember not to water the leaves or the fruit directly. The water should go around the base of the plant, not on the leaves.
Rot can occur on cucumber fruit and leaves if they are watered frequently, so in a greenhouse, I advise setting up a watering system aimed at the roots if possible.
Why does my cucumber have grey mould?
Botrytis occurs in very humid conditions. Has there been a lot of rain or is your greenhouse door always closed?
- Cut off any infected fruit, taking care to wipe the secateurs clean after each cut to avoid spreading disease. Burn or dispose of infected vegetation. Do not add them to your compost or you may spread disease.
- Try to increase ventilation around your plant by cutting off withered leaves and tying up stems.
- Do not water the leaves or the fruit but aim your watering can at the soil and roots.
Why does my cucumber have curled up, discoloured or mottled leaves?
This is caused by greenfly and is called the cucumber mosaic virus.
- First, cut off the infected leaves. Destroy or burn them. Disinfect the cutters after each cut!
- If you use chemicals to control them, you can use permethrin.
- The only other alternative is to try wiping the leaves down with a damp cloth but this may spread the disease even further to healthy leaves.
Why do my cucumbers taste bitter?
Check if your plant is in a draught or has there been a cold spell? If the temperature changes suddenly the result is often a bitter taste to the fruit.
Another possibility is pollination – remember that male flowers should be removed after your pollinate. Some very odd shaped cucumbers which taste bitter can be the result if you forget to do this!