Due to spreading vines and large leaves, crops in the squash family take up a lot of space in the garden. The impressive size of a pumpkin plant means it’s easy to spot if it starts to wilt. While it can be alarming to see a previously healthy plant turn into a drooping mess, a proper diagnosis of the cause of wilting will help you get your crop back to a healthy state.
Wilting can be caused by temperature, water, disease or pest problems. So, the solution depends on the cause. I’ll cover the details of each cause, the severity of the problem, and what you can do to help your plants.
Why is Pumpkin Plant Wilting? 5 Possible reasons
A variety of factors can cause pumpkin leaves to dry out, so it’s important to determine which one is to blame. Here are some common causes of winter squash wilting, as well as ways to fix each problem.
Hot Temperatures
Sometimes, it’s too hot! Many cucurbits (squash family crops) wilt in the heat of a summer day, and then rise when the evening cools. It is very common for pumpkin vines to temporarily wilt in the afternoon. During increased heat waves, this condition is common and temporary.
Before being panic, check if the plants are wilting in the evening or morning. If they back up after the temperature cools, you don’t need to worry. But sometimes, leaves that wilt during the day and fall off at night are a sign of squash vine borers. Once you’ve ruled out extreme heat as the culprit, explore the potential water and disease problems described below.
Very Little Water
Like all plants, pumpkins depend on water for hundreds of different reasons. It transports nutrients throughout the plant, cools the plant on hot days, maintains cell rigidity, allows photosynthesis, and more.
When cells are dehydrated, their cell membranes begin to shrink from the outer cell walls. This phenomenon results in cells shrinking, causing wilting of leaves and stems. When plants have access to more water, their cells harden, and the leaves return to their invisible form. This means that if the leaves are limp, all you have to do is add more moisture and watch the plants perk back up.
Because plants use water to cool themselves through evapotranspiration, they need more water in hot weather than in cool weather. Therefore, you need to irrigate more in the summer than in the fall and spring. During hot weather, pumpkins can wilt during the day, even if the soil is moist. This is because they are losing water faster than they can take it up. As long as they have access to moisture, they will back up overnight.
The ideal irrigation schedule for pumpkins depends on factors including temperature, humidity, plant size, and soil type. In general, you should expect to irrigate every one to five days. If you see wilted and dry dirt, this is likely a sign of drought stress.
I prefer to use drip irrigation for my cucumbers. This method helps keep plants dry and prevent disease by delivering water directly to the root zone. Plus, you can easily set a drip irrigation system on a timer to automate your watering process.
Very High Water
While too little water is the obvious cause of wilting, too much water can also cause leaves to droop. This is because saturated soil can lead to a group of fungal diseases called root rot. This fungus transforms hard roots into soft, mushy structures that cannot absorb water. Therefore, plants cannot access the moisture they need, even if there is enough moisture in the soil.
If you notice that your pumpkin is wilting even though the soil is consistently moist, you may be overwatering. Remember that cucumber is like soil that is moist but not wet. If they are growing in compacted soil with a high clay content, they are more prone to root rot. This is because the moisture stays in the root zone instead of drying out.
If you suspect your plant has root rot, reduce the frequency of watering. A good rule of thumb is to water your plants only when the top two inches of soil feels dry. You can prevent overwatering by amending your beds before planting. If your soil is compact, aerate it with a wide fork or digging fork. Both of these tools will increase air pockets in the soil and allow water to drain. I also recommend adding organic matter to the soil to improve drainage and aeration. A microbial-rich compost not only increases soil organic matter, but also contains beneficial microbes that improve soil health.
Squash Vine Borers
One of the most common pests of cucurbits, squash vine borers can be damaging to all types of squash. Adult moths lay their eggs near the base of cucurbit plants in summer. After the eggs hatch, the larvae burrow into the base of the squash stem and begin feeding. Eating them restricts the movement of water within the vascular system, causing wilting.
If you detect the larvae early and remove them, you may be able to save your plants. However, if left alone, these pests will eventually kill the crop. The first sign of squash vine borer damage is squash leaves that wilt during the day and fall off at night. If you see this happening, check the base of the stem for a small hole surrounded by sawdust-like material. These symptoms indicate that there is a borer inside the stem.
Bacterial Wilt
As its name suggests, bacterial wilt is a type of bacteria that causes plant leaves to drop. Several types of bacteria cause this type of damage, but Eronia tracheophila infects cucumbers, including cucumbers, melons, zucchini, and pumpkins. Cucumbers and melons are more susceptible than squash, but it is not unheard of to get sick.
After pumpkins are infected, their leaves begin to wilt. Symptoms may initially appear on a small part of the plant, but will eventually spread throughout the plant. Unfortunately, there is no cure for bacterial wilt.Since there is no cure for this disease, prevention is your best strategy. Because cucumber beetles are killed by bacteria, the disease only affects plants when the beetles feed on the plants. This means that controlling the beetles is the best way to prevent infestation.
