Cucumbers grown in the greenhouse should be grown vertically up a trellis, string, cane or other support structure.
When you train your cucumbers into growing up support, you will have no doubt wondered what you should do with side shoots. Should you pinch them out? Well, let me answer that for you.
Should I Prune Cucumbers?
To maximise your cucumber harvest, you should prune out some of the side shoots. If you allow many side shoots, you will have tons of leafy growth but not many cucumbers.
Why do we pinch out cucumbers?
The simple reason why it is recommended to pinch out cucumbers is to encourage a large crop.
If you let side shoots grow out, the plant will put lots and lots of energy into growing sideways.
While these sideways growths will produce fruit, they will mainly consist of lots and lots of large leaves. Growing these side shoots and leaves takes energy away from fruit production.
There is a limit to the amount of growth a single cucumber plant can support.
By leaving side shoots to grow then, more of this growth goes into leaves and stems rather than fruit production.
How to pinch out cucumbers
You want to prune any growth that is not on the main stem. In the photo below, you can see a side shoot that has been allowed to grow.
You want to cut this off at the stem with a pair of sharp secateurs or a pruning knife.
Leave a little side growth
This is another method you can use if you want to encourage a little side growth.
If you don’t have that much height to grow your cucumbers, then a little side growth will be beneficial.
A cucumber can quickly reach 6ft in height, and if you don’t have the height to allow it to grow up to or past this, then a little side growth is no bad thing.
The easiest way to allow a little bit of bushier growth is to let the side shoot grow for a little while and look for a female flower to appear.
A female flower has a baby cucumber behind the flower, so they are really easy to spot.
Once the flower has appeared, you can cut the stem after the female flower.
I usually leave another leaf on and then make the cut, as you don’t want to cut too near to the fruit and risk damaging it.
I have edited the photo below to show you where I would make the cut if I wanted a little sideways growth.
This allows the plant to bush out a little while remaining productive.
Topping Cucumber Plants
Topping is simply means removing the growing tip of the main vine stem. This process helps to redirect the plant’s energy towards developing the cucumbers already on the plant and also bushing out.
The energy is redirected towards the remaining cucumbers by topping the plant, resulting in larger and more fruit.
Topping also helps to promote the growth of lateral branches. The lateral branches grow from the nodes on the main stem, producing more cucumbers, increasing the plant’s yield.
It is important to note that topping should only be done once the plant has reached a certain height. Topping too early can reduce the plant’s productivity.
Topping also affects the plant’s growth hormones and dominance. When the growing tip is removed, the plant’s apical dominance is reduced, allowing the lateral branches to grow more vigorously. This process helps to balance the plant’s growth and promote its productivity.
What this means is that once you top it, you are really going to notice those side shoots growing. This is perfect if you have lots of room for lateral growth, but if you don’t then its going to take more work to stay on top of.
Alternatives to topping
A couple of options are open to you if you don’t have much lateral growing room and don’t want to top your cucumber plants.
First, you can allow them to continue growing up, but train them along your roof.
This is a simple option and allows you to continue growing the plant in much the same way as you always have.
Another option is to lower the plant. I often do this with my tomatoes to extend their growing season, and the same thing can be done with cucumbers.
This is usually done with tomatoes/cucumbers that are growing up string.
You release the tension at the top of the string and allow the bottom of the stem to grow horizontally along the floor before then growing vertically.
This essentially gives you another 2 or 3ft of growing space, without having to do anything.
The Process of Topping Cucumber Plants
To top a cucumber plant, follow these steps:
- Identify the plant’s growing tip, which will be located at the top of the main stem.
- Using a sharp pair of pruning shears, make a clean cut just above the second or third leaf node below the growing tip.
- Dispose of the removed plant material to prevent the spread of disease.
Topping should only be done on healthy plants, as stressed or diseased plants may not respond well to topping.
Potential Risks and How to Mitigate Them
Topping cucumber plants can be a useful technique to manage the growth of the plant, but it also comes with some potential risks.
Risk 1: Disease
When the plant is cut, it creates an open wound that can attract pathogens and pests. This can lead to the spread of diseases, such as powdery mildew, which can affect the overall health of the plant.
To mitigate this risk, it is important to make sure that the cutting tools are clean and disinfected before use.
Additionally, it is recommended to top the plants in the morning when the weather is dry to reduce the risk of moisture getting into the wound.
Risk 2: Branches
Topping can also cause the plant to produce more lateral branches, which can lead to overcrowding and reduced airflow.
This can create an environment that is conducive to disease and pest infestations. To mitigate this risk, it is important to monitor the plant closely after topping and remove any lateral branches growing too close together or blocking airflow.
Risk 3: Pests
Topping can also attract pests, such as cucumber beetles, which can cause damage to the plant. To mitigate this risk, it is important to monitor the plant closely for signs of pest infestations and take appropriate measures to control them.
This can include using insecticidal soap or neem oil, introducing beneficial insects, or using physical barriers, such as row covers.
Frequently Asked Questions
How often should I prune my cucumber plants?
Cucumber plants should be pruned regularly throughout the growing season. It’s important to keep an eye on the growth of the plant and prune as needed.
This can involve removing extra leaves, stems, or shoots that are not necessary for the plant’s overall health.
What are the benefits of pruning cucumber plants?
Pruning cucumber plants can help to improve airflow and reduce the risk of diseases like powdery mildew.
It can also help increase the plant’s yield by directing more energy towards producing fruit. Additionally, pruning can make it easier to trellis the plant and save space in a small garden.
At what point in the growing season should I start pruning my cucumber plants?
It’s recommended to start pruning cucumber plants when they reach about 12 inches in height.
This will help to ensure that the plant is healthy and producing fruit throughout the growing season. Pruning should be done regularly throughout the season to keep the plant in good shape.
How do I know when it’s time to remove my cucumber plants?
Cucumber plants typically have a lifespan of about 60-70 days. If the plant is no longer producing fruit or is showing signs of disease or damage, it may be time to remove it. Additionally, the plant should be removed if it has reached the end of its growing season.
What is the purpose of trimming a cucumber plant?
Trimming a cucumber plant can help to direct its energy towards producing fruit and improving overall health. It can also help to prevent the plant from becoming too large and unwieldy, making it easier to manage in a small garden.
Does topping cucumber plants affect yield?
Topping cucumber plants can actually help to increase yield by directing more energy towards producing fruit. However, it’s important to top the plant at the right time and in the right way to avoid damaging it.