5 Reasons for Cucumber Leaves Curling [Fixing Guide]

Cucumbers are a joy to grow. Every gardener wants a corner of his garden for growing refreshing cucumbers to enjoy on a hot day.

Although cucumbers are very easy to take care of, some issues may need your attention.

Curling up of leaves is a common problem of cucumbers. So if you see your cucumber leaves suddenly starting to curl up, you need to take some immediate action.

But before taking any steps you need to know why the leaves are curling up. Because the wrong kind of treatment can hurt your plants.

Curling up of the leaves is one of the earliest signs of stress of the cucumber plant. It can happen due to Water Stress, Nutrient Deficiency, Environmental Stress, Aphid attack, and some Diseases.

So without any delay, let’s get straight to the point-

Reasons and Solution For Cucumber Leaves Curling Up

1. Water Stress Of Cucumber

Water stress can result in the curling up of cucumber leaves. Especially for young cucumber plants. Because young plants do not have a very developed root system. When the plants don’t get enough water, they quickly start to curl up. 

But overwatering also can be the cause of leaf curl. So, it is better to check the soil moisture with a moisture meter(our pick: Atree 3-in-1 Soil Tester Kits with Moisture, Light, and PH Test for Garden) before treating it.

Don’t have a moisture meter? Dip your finger into the soil and check if it is moist or dry.

Control Measure

Water your cucumber vines 3-4 times a week depending on the environmental conditions. You don’t need to water if there’s frequent rain. You can also do some light watering if the soil seems too dry.

Sometimes the soil gets compacted and as a result, water cannot reach the root zone. In this case, loosen the soil with a spade without hurting the roots.

You can also improve the soil drainage by adding sand, vermiculite, or perlite (our pick: Miracle-Gro Perlite)

Add organic mulch such as straw, bark chips, wood chips, dry leaves, compost, etc. These will help to keep the moisture in dry conditions. 

2. Nutrient Deficiency of Cucumber

The deficiency of Nitrogen, Potassium, Magnesium, Calcium, Sulfur, and Zinc can curl the leaves inwards and make the leaves look wrinkled.

This problem can be very common if the land is not well prepared with fertilizers. Cucumbers are heavy feeders of nutrients. So it’s very important to provide the right amount of nutrients into the soil for better cucumber production.

But only by seeing the shriveled up leaves, you cannot determine what is the nutrient deficiency of the soil.

You have to test the soil in a lab. But you can also do a quick pH test to get an idea of the deficiency. For example, acidic soil can indicate calcium and magnesium deficiency. 

Control Measure

Cucumbers usually require more nutrients than other tropical vine plants, especially Nitrogen. 

Apply a well-balanced vegetable fertilizer that contains all the macro and micronutrients for cucumber including magnesium, iron, and calcium. (our pick: Miracle-Gro Water Soluble Plant Food Vegetables & Herbs)

But if you pick fertilizer that doesn’t contain magnesium, iron, and calcium, what will happen? 

Don’t worry, along with fertilizer, you can add a tablespoon of Epsom salt(our pick: Epsoak Epsom Salt) and a tablespoon of chelated iron (our pick: Southern Ag 01952 Chelated Liquid Iron), and a tablespoon of bone meal to provide magnesium, iron, and calcium respectively.

Add well-prepared compost and manure or balanced fertilizer to your garden before planting cucumbers to avoid future deficiency problems.

3. Environmental Stress of Cucumber

Cucumbers are sun-loving vines but too much sunlight can cause the cucumber leaves to curl up and turn brown

Even too much heat can do the same thing too. Excessive heat leads to evaporation and causes the leaves to curl up to conserve water. 

Another reason why the leaves curl up is heavy pruning.

Sometimes cucumbers need pruning for better cucumber growth. Heavy pruning can result in curled-up leaves reacting to pruning shock.

Control Measure

Cucumbers need 6 to 7 hours of sunlight every day. If it’s getting too much heat and sunlight, relocate the plant to an area where there is less sun exposure. If you are growing in the greenhouse then consider changing the artificial lighting schedule. 

Don’t over-prune the plant more than necessary. Prune once in 2 or 3 weeks only if the vines are becoming too bushy. 

4. Aphid Attack Of Cucumber

Some pest attacks can result in the curling up of leaves including aphids, thrips, and whiteflies. 

But aphids are the most common and troublesome pests in the case of cucumber leaf curling. Aphids generally stay on the leaves and vines. They make tiny little holes in the plant and that curl up the edges of the leaves.

Aphids may be white, black, or pink in color. Check the lower side of the leaves. Since they are very tiny you may not be able to see the bugs sometimes. But you will notice a sticky substance called honeydew. 

Aphids secreted honeydew coats the leaf and hamper photosynthesis. And this leads to yellowing and curling of leaves.

Control Measure

Simply rinse the aphids off with a water hose giving a gentle or strong speed of spray. 

If rinsing the aphids off doesn’t work then you have to use a good pesticide. Remember to always use a safe pesticide. Because some pesticides contain harmful chemicals that can affect the quality of your cucumbers. You can try Monterey LG6150 Garden Insect Spray.

Here are some helpful and effective homemade insecticide recipes you can try –

#Recipe 1- Horticultural Oil Recipe

Ingredients

  • 1 tablespoon of liquid soap 
  • 1 cup of any oil like soybean oil or olive oil or vegetable oil. 

Steps

  • Mix these ingredients very well and store the mixture in a bottle.
  • Add a tablespoon of this mixture with every cup of water and pour it into the sprayer.

#Recipe 2- Neem Oil Recipe

Ingredients

  • 1 tablespoon of neem oil 
  • Half a gallon of water 

Steps

  • Mix the ingredients and spray in the plants every week.

#Recipe 3- Basil Tea Recipe

Ingredients

  • 1 Cup of fresh basil
  • 1 teaspoon of liquid soap
  •  4 cups of water

Steps

  • Bring the water to a boil and then remove it from heat
  • Add the basil leaves and cover the pot.
  • Wait until the water cools down and then strain the leaves
  • Mix the liquid soap and put the mixture into the sprayer
  • It’s very effective against aphids.

#Recipe 4- Tomato Leaf Spray Recipe

Ingredients

  •  1 cup of tomato 
  • 2 cups of water

Steps

  • Chop the tomato leaves and let them stay overnight in a cup of water. 
  • Then strain out all the leaves and add another cup of water to dilute the solution. 
  • Spray on the leaves twice a week. Tomato leaves have some natural compounds that are toxic to insects but completely safe for plants and humans.

Note: In the case of all homemade recipes, always use the mixture in a small area of the plant first. Wait out to see how it reacts. If the leaves burn or wilt then you can skip spraying the mixture. Or you can dilute the solution to make a milder mixture and try in a small portion again. 

5. Diseases of Cucumbers

Some fungal and viral diseases can make the seedlings curl underneath. 

The cucumber mosaic virus can cause the leaves to roll upward and turn yellow with a wrinkled appearance. Very old and very young infected plants are most susceptible and often die of this virus.

Downy mildew is a fungal disease that can also curl up the leaves. Downy mildew prefers a temperature of 20-30° C in wet and humid conditions for its rapid infection. 

Control Measure

Aphids and other insect pests play a vital role in spreading this cucumber mosaic virus disease. so it is very important to take steps to control pest problems. 

To downy mildew, remove all the curled cucumber leaves. After that, apply a fungicide that does not contain any toxic chemicals(our pick: Bonide Copper  Fungicide)

Also, I’ve added some practical home-made recipes that you can try for downy mildew and other fungal diseases-

# Recipe 1- Baking Soda Spray Recipe

Ingredients

  • Baking Soda 1 teaspoon
  • Few drops of liquid soap
  • 1 liter of water

Steps

  • Mix the ingredients well and spray thoroughly on both sides of the leaves.

#Recipe 2- Vinegar Spray Recipe

Ingredients

  • 1 tablespoon of apple cider vinegar 
  • 2 liters of water
  • Few drops of liquid soap

Steps

  • Mix the ingredients very well and spray on the infected leaves twice a week.

# Recipe 3- Epsom Salt Spray Recipe

Ingredients

  • Half a tablespoon of Epsom salt 
  • 1 liter of water

Steps

  • Mix very well.
  • You can spray this solution every week.

# Recipe 4-Milk Spray Recipe

Ingredients

  • 200 ml of sour milk 
  • 200 ml of water 

Steps

  • Mix very well
  • Use it as an instant mixture 
  • Spray it twice a week until the problem stops.

Preventive Measure

Try planting resistant varieties like “Liberty Hybrid,” “Saladin” and “County Fair 83” that are available in the market. And Before planting treats the seeds with a good seed treating solution.

Downy mildew spreads very fast through water movement. To discourage fungal growth, water the plants from the base. Avoid wetting the leaves. 

Keep 20 cm of a gap between each plant for better airflow. Because dense planting can encourage fungal growth.

Conclusion

In this article, I have tried to include all the information about the cucumber leaves curling up with their practical treatments. I hope you find this article helpful.

Maintain a watering schedule, feed the right amount of fertilizers, and take quick steps for diseases and aphid attacks.

Don’t forget to share your experience with the curled-up leaves in the comments below and let us know how you treated them. Your experience can help others.

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