Why Are My Cucumber Leaves Dropping?

The crunch and refreshing taste of cucumber are loved by all. It’s a summer staple in many home gardens. It’s the star of salads and a great filler for side dishes. If you have been getting your cucumbers from your garden, you know important it is to maintain the crop to protect it from pests and bacteria.

Cucumber leaves are susceptible to drooping and dying, which is why they shouldn’t be planted too early in the season. The ideal time for cucumbers to grow big and less watery is two weeks after winter. The moment the chill disappears, start counting the days. If your soil temperature is lower than 21ºC, the plant won’t grow.

Cucumber leaves are quite delicate, which is why you need to inspect them every now and then to make sure they don’t succumb to any problems. It often happens that even though the cucumber leaves are dying, the fruits are still intact.

A common problem with growing cucumber plants is that sometimes, you have to hand-pollinate them. Although bees are the primary pollinators of cucumbers, they might get attracted to other plants in the garden. The good news is that you can easily do this by picking up the pollen with a cotton swab from a male cucumber plant and depositing it in the female cucumber plant’s ovaries.

The point of telling you this is that without pollination, you get deformed cucumbers, which dry up fast. The flowers slowly start to die as well, inviting insects to feast on the buffet, causing the plant to wilt and eventually die.

Let’s take a look at some of the top reasons why cucumber leaves wilt and die:

Bacterial Wilt

Erwinia tracheiphila is a bacteria that causes cucumber leaves to wilt. This bacteria is found in Diabrotica and Acalymma, which are known as cucumber beetles. They feed on cucumber leaves and create small wounds that invite other insects. Bacteria is transferred from the beetle’s dung into the plant through the wound, infecting it and transferring it to other cucumber plants.

It only takes a single beetle to infect the plant and infect the entire crop. Spotting the beetles might be difficult, but a few signs will let you know that your cucumber plant is dying. These signs include leaves wilting, dry stems, and loss of color. The reason why the leaves wilt is because the bacteria inhibit water from reaching the roots or traveling through the plant.

Solution

Sadly, there’s no treatment for bacterial wilt. Though, you can take a few preventative measures. Let’s say that you have a dozen cucumber plants in your garden. During your routine inspection, you spot one of the plant’s leaves wilting. You then spot the beetles feeding on the stem. The first thing you need to do is rip the plant out and dispose of it far away.

Inspect the other plants thoroughly and install a pest net. This will prevent the beetles from accessing your plants. You can also use pesticides to stop the beetles from attacking your plant.

Cucumber beetles usually attack a plant that is weak. So, to keep your plan safe, take a few precautionary measures.

  • Do not plant your cucumbers near plants that beetles like, such as goldenrod and corn
  • Once beetles have infected your plant, remove your cucumbers and plant them somewhere else

Squash Vine Borers Infestation

This is a type of infestation that usually affects squash and melon. However, in some cases, it also transfers to nearby cucumber plants. The larvae are cream-colored and large, and they chew on the plant’s stem. Once they get inside, they continue eating until they have reached the leaves and fruit. After feeding on the cucumbers, the larva turns into a flying insect that has black wings. There’s no coming back from this infestation because the larva leaves a husk of the cucumber plant, which is devoid of everything that makes it.

Squash Bug Pests

This insect forms a large gathering on the cucumber stem and leaves. This cluster slowly consumes the plant and prevents nutrients and water from reaching the roots. Due to this, the plant fails to thrive, eventually wilting and dying. An effective way to control this pest is to spray the surrounding soil with an insect killer.

Phytophthora Blight (Crown Rot)

Crown rot is a result of a fungus that completely changes the appearance of cucumber plants. According to a study by Cornell University, it causes damp, brown spots on the stems, leaves and fruits. As the rot spreads, it turns into white mold.

This growth indicates the plant is rotting. The fungus eats the plant’s every part, causing it to wilt. You can get rid of this problem by spraying the plant with a fungicide. However, if your plant is too far gone, it’s possible that you might not be able to save it.

If you think your plant has a chance of surviving, you can use a DIY remedy of Neem oil, baking soda and water. Mix these ingredients and pour the solution into a spray bottle. Wet the moldy growth with this solution and then pluck the infected leaves.

Overwatering

Overwatering is a problem with every plant. Just because your plant seems dry does not mean that it needs to be watered! According to a study by the University of Minnesota, cucumbers will turn brown and wilt if the soil temperature is 16 °C.

A cucumber plant needs a special type of soil that promotes drainage and does not have a high amount of clay. The soil needs to be rich in moisture but not too much, or it will block the roots from absorbing the necessary nutrients needed to keep the plant healthy.

The soil must be moist but not muddy. You can test its texture by inserting your finger into the soil till the second knuckle, around 2 inches deep. If the soil feels dry, water your plant immediately. Track the soil moisture to develop a watering routine.

Cucumbers love the sun. However, direct sunlight can dry them out. Typically, cucumbers should be watered every week through a soaker hose or drip irrigation. If you feel that the plants are drying up quickly, spread mulch around them to trap the moisture.

Diseases

The cucumber mosaic virus is a disease that is spread by cucumbers. The initial signs of this virus are yellow streaks that appear on the leaves and cucumbers. These streaks cause the fruit to grow small and misshapen.

In order to stop this virus from infecting your cucumbers, you need to keep the plant hydrated and ensure it is not receiving too much nitrogen from its fertilizer. This will cause the leaves to grow big, which will then tip the balance of the plant.

Prevent Cucumber Mosaic Virus 

  • Keep the soil moist and well-drained by packing the roots with compost tea or manure for nutrients
  • Sprinkle a solution of Neem oil and water on the leaves before the fruit blossoms. This works as a great insect repellent. It also prevents fungus growth on cucumbers
  • Plant your cucumbers 16 inches apart, so each one receives its fair share of sunlight, water and plenty of space to grow

Cucumbers hate soggy soil. Hence, you should always plant them in moist soil. Instead of using commercial fertilizers, try DIY remedies to give your plant the nutrients it needs to grow tall and strong.

Cold Weather

Cold is not a friend of cucumbers. The lower the temperature falls, the more the leaves will start to wilt. This happens because cold weather prevents the plant from absorbing water. If the ground is frozen, the roots won’t be able to deliver the nutrients. Moreover, the wet and cold soil causes fungus to develop at the roots, which weakens your plant. If the temperature goes below 10 °C, inspect your plants at the base for fungal growth.

Fungal growth is inevitable because the weather cannot be controlled. However, you can take measures to mitigate its effects. If the weather forecast says the next few days are going to be colder, pack your plant with mulch. This will insulate the soil, prevent water from freezing and keep the roots warm.

In winter, water your cucumber plants with room temperature water. This will knock off some of the chill and keep the soil all toasty.

Drought and Heat

We have already talked about why cucumbers love warm weather. It creates the perfect environment for them to grow. However, sometimes the warmth can be too much, which can cause them to wilt. A great way to find out if your plant is getting too much sun is to water them.

If you notice a change in their structure after a couple of hours, move them to a shaded place until the weather settles. Sunlight is at its peak during the afternoon. At this time, the soil will dry out quicker, so keep watering the plants after every two hours.

Seedlings Dying

The droopy leaves on the verge of dropping are caused by overwatering. Give your cucumber plant a little break so its roots can dry. Do the finger test before watering your plants again.

Overwater also leads to algae and fungus that cause cucumber leaves to die. The key to correcting this problem is planting your cucumbers in the right environment. If you are unable to grow your cucumbers in the garden, look for a shaded area that shields the plant from direct sunlight and allows the soil to retain moisture.

Soil pH

In order to survive, cucumber seedlings require a pH level of 6. This allows the plant to grow tall with bright leaves.

Adjust pH Levels

Wilted cucumber leaves might also be a result of a low pH level. You can rectify this problem by giving your plant potassium-rich fertilizer. Cover the roots with it so that they can absorb all the nutrients and deliver them throughout the plant.

Adjust the Environment

When cucumbers grow in a dry and hot location, the soil turns warm and evaporates all the water. In such a scenario, move your plant to a cooler area. As mentioned earlier, cucumbers are quite sensitive. When they don’t receive an adequate amount of water, the leaves turn yellow and drop to the ground.

So, make sure that your plant stays as cool as possible. If your plant’s condition stays the same for a week, give it a small dose of potassium-rich fertilizer.

When planting new cucumbers, put the seeds into the potting mix and place the pots on your windowsill. Make sure the soil is moist but not soggy.

Cucumber Care

Cucumber plants require a little more care because they have a sensitive structure. Here are a few tips to keep them healthy:

  • Water your cucumber plants twice a week using a hydroponic system’s reservoir
  • Water the plants in the morning so you don’t have to worry about them staying for too long in the soil
  • Spray your plants mid-day in summer
  • If you see wilted leaves, a common cause could be overwatering. When the roots don’t get time to recover, they are unable to send the nutrients to the leaves, making them look droopy
  • Cucumber plants are heavy feeders. An occasional round of fertilization with a combination of high potassium and low nitrogen after every few weeks will keep them healthy
  • Trim the diseased parts of the plant to prevent the virus from spreading. Use a sterilized knife to cut the leaves. When cutting the steam, keep going until you reach a clean surface and then plant the cucumbers in fresh soil

Final Thoughts

Now that you know why your cucumber leaves are wilting and dropping, you can take the necessary measure to nurse the plants back to health. Keep in mind that there’s no cure for bacteria tilt. So, if you spot any wounds on your plant’s stem, rip it out and throw it far away to prevent contamination.

Depending on what’s causing your cucumber leaves to drop, you might need to change your maintenance routine and change soil often to keep the plants healthy. So, follow the steps mentioned above, and you will be enjoying g your homegrown cucumbers in no time. If you want to know more about cucumber plants and how to take care of them, visit the Mo Plants website. They offer growth and maintenance guides for all types of plants.