Why Are My Cucumbers Curling?

When we picture an abundance of cucumbers harvested from our garden, we expect to see perfectly straight fruit with deep green skin bursting with a watery center.

Sometimes things don’t go to plan in the garden, and we encounter some unusual mishaps along the way.

This cucumber season, I noticed something a little off with my fruits, and that was they weren’t quite straight like you buy from the supermarket – they were curling.

I left a few on the vine to see if they would miraculously straighten out over time, but no… they didn’t!

This has led me to do a bit of scratching around on the net to see what I have done or what the cause is. I found a few reasons why cucumbers curl and have the pleasure of sharing them with you in this article.

Why Are My Cucumbers Curling?

Cucumber curling is also known as Crooking and is more common than you might think.

Reasons for your cucumbers curling can be because of poor pollination, unsuitable growing conditions, lack of nutrients, physical obstructions, indirect sunlight, and pest infestations. 

Poorly Pollinated Flowers Cause Curly Cucumbers

Poorly pollinated flowers are the leading cause for cucumbers to curl when they are growing. Cucumbers use bees, flies, and other insects to pollinate their flowers.

When a limited part of the flower’s ovaries is pollinated, it causes one side of the small cucumber to grow at an angle. When the cucumber continues to grow, one side becomes longer than the other, causing them to curl.

To ensure proper pollination of your cucumber flowers, you can give them a helping hand.

During the flowering period, take a visit to your cucumber patch each morning. Gently brush the inside of the flower with a paintbrush to make sure the pollen is reaching the sigma evenly so the ovaries receive an adequate amount of pollen.

Curly Cucumbers from Unsuitable Growing Conditions

During the fruiting period, Cucumbers require particular growing conditions, and due to any fluctuations in temperature, humidity, and sunlight, they can produce curly cucumbers.

When growing cucumbers outdoors, ensure the soil is at a temperature above 60°F (16°C). The best-growing zones for cucumbers are zones 4-12.

You can add a layer of mulch to keep the soil warm and retain moisture. Some gardeners like to grow cucumbers in a greenhouse or polytunnel and still experience curling cucumbers; this is normally a result of high humidity and poor ventilation.

If you are growing cucumbers in a greenhouse or polytunnel, make sure you open a vent in the afternoon to give it some airflow and reduce the risks of pests and fungal infections.

Lack of Nutrition Creates Curly Cucumbers

Cucumbers require a regular feeding plan to produce good fruit, and if they are not receiving the right amount of nutrients from the beginning, it can cause the cucumbers to curl later on.

When planting cucumbers, ensure they have a good dose of balanced fertilizer 13-13-13 NPK (nitrogen-phosphorus-potassium).

The ideal amount should be 6 ounces (177.5 ml) at the start and then as the vines continue to grow, add the same dose every two to three weeks.

Make sure when buying the right fertilizer you choose an organic brand or have a go at making your own from a mix of wood ash, rotted animal manure, and organic materials.

That way, you are reducing the number of harmful chemicals in your garden and kitchen.

Missing a week or two of no fertilizing causes the fruit to grow unevenly inside, which results in curling.

Physical Obstructions Cause Cucumbers to Curl

As cucumbers are a vining plant, they can easily take over a lot of ground space in the garden. When it comes to fruiting time, the cucumbers will be on the ground, where they encounter various physical obstructions such as vines, leaves, and flowers.

The fruit will continue to grow around the obstructions, resulting in deformed, curled fruit.

When growing cucumbers, try to grow them vertically up a trellis or a chain link fence; that way, when they are fruiting, they will hang down and have the opportunity to grow straight.

If the young cucumbers don’t have the right amount of space around them to fruit, they will start to curl and won’t straighten out.

Indirect Sunlight Contribute to Curling Cucumbers

Cucumbers love 6-8 hours of sunlight per day, and if the fruit is in shaded sunlight, this can cause the cucumbers to grow unevenly and curl. The sunlight must be distributed across the fruit to ensure it will grow evenly.

When planting your cucumbers, grow them up a trellis or vertically and ensure the fruit is not overcrowded by foliage.

Choose a position that receives at least 6 hours of sunlight daily and is not shaded by other tall growing plants in the garden.

Curling Cucumbers as a Result of Pests

Infestations of pests such as whiteflies, thrips, mealy bugs, aphids, or scales will affect the cucumbers’ shape. These pests are known to suck the sap from the cucumbers, causing wounds in your fruit and affecting the shape’s development.

The best way to control pest infestation is to regularly check for any of the pests for early detection. You can use insecticidal or neem oil foliar spray each week until you see the numbers reduce.

Try to stick with organic pest control when growing cucumbers and other vegetables, as you don’t want to be ingesting any nasty chemicals when it comes to harvest time.

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Wrapping Up

Cucumbers are a great crop to grow and can produce a lot of fruit from one plant. Although we recognize cucumbers to be perfectly straight, they are still edible when they are curly, so there is no need to waste the slightly deformed ones.

Make sure to regularly harvest your cucumbers when ready, as this will allow them to set new flowers and continue attracting pollinators.

Growing your own vegetables shows you that, in nature, not everything is perfect. Although some people envisage the picture-perfect fruit and vegetables from their garden, it can be far from reality.

Taking some of the steps discussed in this article ensures that you are doing as much as possible to ensure your cucumbers have the best chance of looking good at the table!