Pumpkins are edible fruits that are grown for food or recreation. The leaves of this North American native are round, large, and lobed with three or more veins.
Pumpkin leaves wilt by turning yellow and drooping. If the leaves on your Pumpkin are also wilting, continue reading to find out the possible causes and solutions.
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Why Are My Pumpkin Leaves Wilting?
Pumpkin leaves mostly wilt after an insect infection by vine borers or squash bugs. But diseases can also cause wilting. The most common disease on Pumpkins is bacterial wilt that blocks the vascular system of the plant. Other diseases that lead to wilted leaves include fusarium fungus and phytophthora blight. The leaves also wilt and have a droopy appearance due to a lack of moisture on hot days.
1. Insects
The following insects are responsible for wilting leaves on Pumpkins.
Vine Borers
The larvae for these insects love feeding at the base of the stem. It results in yellow or wilted leaves. These insects will roam around your plants at the end of June. To prevent them from laying eggs, watch out for your plants during this time of the year.
I would suggest setting up yellow trap pans that are filled with water because the adult borers are attracted to yellow. They will fly towards the trap and drown/trap in the water.
You will find green or orange matter at the base of plants infected with vine borers.
You should dig up all the plants destroyed by the vine borers. If this happens after initial planting, you can try planting another batch of Pumpkin plants.
Squash Bugs (Anasa Tristis)
These are terrible bugs that enjoy munching on Pumpkins. They have wrinkled caterpillar-like bodies with clear wings.
Once they are done feeding, your plant leaves will wilt and turn yellow. The adults can overwinter in corners of the leaves, and they start laying eggs on the foliage of the Pumpkin plant in spring.
One common symptom of their presence on your plant is a sawdust-like matter near the wilted stems or leaves. The adult bugs are 5/8 inches long, and the nymphs are ½ inches long. The squash bugs feed actively from May to September.
These multiply fast, so you will find the eggs, nymphs, and adults on your plant. They feed on the plant by sucking the juices, which interrupts the flow of nutrients and moisture.
To check your plant for insects, you should inspect the base of the plant for insect poop (frass) or tiny holes. If you cut a vine that has white holes, you will find more squash borers inside the stem.
2. Diseases
Bacterial Wilt
This wilting is caused by a bacterium called Erwinia tracheiphila. It spreads via cucumber beetle. It blocks the water intake by invading the vascular system of your Pumpkin plant.
The symptoms of bacterial wilt are often confused with heat or water stress. Initially, the wilted leaves recover at night. But the Pumpkins infected with bacterial wilts will eventually die.
This wilting begins with one leaf but soon, the whole plant wilts. Bacterial wilt can be confirmed by cutting a wilted stem at ground level that is still attached to your original plant. Inspect the cut end. If white sticky goo comes, your plant is infected.
Once your Pumpkin plant is infected with this wilt, it cannot be cured. You will have to remove all the sick Pumpkins from your garden to prevent the disease from spreading. This disease spreads fast, and it can kill young Pumpkins within few weeks.
Fusarium Fungus
This fungus lives in the soil and can spread even by the wind. This fungus causes crown rot, and the initial symptoms are yellow foliage, wilting, and necrosis. This disease has no chemical control, and it can even overwinter in the soil.
Phytophthora Blight
This fungal disease can also overwinter. This disease will spread in wet and cool weather. Crop rotation is a wise solution for this disease, but you can also use a fungicide. Please remember that fungicides should be used only according to the label instructions.
You can prevent phytophthora blight by using soil that drains well.
3. Lack of water
Pumpkin plants have large leaves that shade the soil to reduce the evaporation of water from the soil. This does not mean you should water your plant less because lack of water can lead to wilted leaves on a Pumpkin plant.
Often times Pumpkin leaves wilt during the heat of the day. This is temporary wilting, and the leaves will go to their normal appearance once the weather improves. But if you notice wilted leaves early morning, your plant is facing water stress.
Wilting can also occur due to high temperature or sunlight because the plant is losing water faster. This also indicates a poorly developed secondary root system of the plant. I would suggest shading your plant on hot days to reduce the rate of water evaporation.
Fixing Wilting Pumpkin Leaves
Get Rid of the Insects
If your plant is young, I would suggest placing row covers to protect them from insect attacks. This is important because young Pumpkins are more vulnerable to insect damage.
The cucumber beetles can be controlled using rotenone or sabadilla, two of the oldest natural insecticides.
If your plant is wilting during the early days of the growing season, you can use the help of a fungicide to kill the squash bugs. A simple solution is to remove all the nymphs and adults using soapy water.
To avoid insects in the future, you should keep a close eye on the Pumpkin plant. You should also maintain good plant hygiene by removing weeds and debris near the base of the plant.
Remember, a healthy plant can fight insects or bugs better, so maintain the soil, water, and nutrients requirements of your plant.
Maintain Proper Watering
Lack of water is a major concern for Pumpkins in hot summer. Usually, they need about 1 to 1.5 inches (2.5 to 4cm) of water every week. If the weather is continuously hot, you will have to increase the frequency of watering.
The proper way to water a Pumpkin plant is to water at the base, slowly and deeply. You should not water using overhead watering.
Mist your Plant
Pumpkin plants struggle in hot temperatures and high sunlight because the transpiration rate is higher.
This is not due to a lack of water. Instead, the plants cannot soak the moisture fast enough to compensate for the loss of water due to high transpiration.
You can lower the water loss in stomata and the transpiration rate by misting your Pumpkin plants. This lowers the temperature around your plant and increases humidity. Which eventually improves the water uptake of your plant.
You can also mulch the soil surface to reduce evaporation.
Some growers start overwatering their plants to compensate for the lost water, but that will only damage your Pumpkin plants.
Frequently Asked Questions About Wilting Pumpkin Leaves
Can sunlight cause wilted leaves on Pumpkin plants?
Although these plants prefer full sun, if your Pumpkin plants are continuously exposed to bright, hot afternoon sun, the leaves will start wilting. These leaves wilt during the daytime (in the hot sun) and perk up at night. But if the leaves are wilting before peak hours, i.e., before 11 am, your plant simply needs more water.
Should I trim the wilted leaves on my Pumpkin plant?
If your plant is not showing any sign of recovery, I would recommend trimming the wilted leaves using sterilized gardening tools.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.