Pumpkin season is just around the corner, but even our spooky favorite is susceptible to disease. This is why it is important to keep an eye on your plants throughout the season. If you notice an issue you might still have time to correct pumpkin problems.

Powdery Mildew

If I would guess, I would say powdery mildew is probably the number one issue that many pumpkin growers face. As the name implies it looks like somebody sprinkled baby powder on the upper side of the leaves making it very easy to spot.

This fungus prefers hot temperatures, and often infects plants in the middle to late season. Depending on the severity of the infection the pumpkin growth may not be effected. But in extreme cases it can deformed the fruit. The best way to combat this common issue is to grow powdery mildew resistant plants. If you have a favorite that is not resistant, you can be vigilant with a fungicide to try to stop it or slow it down in the early stages.

Downy Mildew

While powdery mildew prefers warm conditions, downy mildew thrives when it is cool and wet. It also initially affects the upper parts of the leaves, but instead of the powdery appearance, there are yellowish lesions. Because downy mildew typically infects plants later in the season when the late summer rains arrive in many areas, one recommendation is to plant varieties that ripen early. 

Pumpkin Disease Control

Identifying Anthracnose 

Yet another fungal disease, anthracnose is a serious issue for pumpkins and other cucurbits. It’s found in both infected seed, as well as in the soil, and can show up early in the season. It thrives in hot, humid weather, but this doesn’t predicate it from appearing in less desirable conditions. If it doesn’t wipe out the transplants at an early stage by affecting the cotyledon, you might notice it on mature leaves. It initially takes on the appearance of downy mildew, but the lesions rapidly enlarge engulfing the leaf. Sometimes fruit dies on the vine, or you might notice an infection with dark spots that quickly sink and destroy the pumpkin.

The best way to combat the serious disease is to grow resistant varieties. Always rotate the crop at least every couple of years, although every year is ideal. And if you do have infected vines or fruit, burn or dispose of them away from the garden.

Planting Pumpkins: Timing and Variety Suggestions

Phytophthora Blight 

Growing up in Ohio, pumpkins were a big deal at the farm. I did not realize that recently Phytophthora blight is one of the greatest problems for growers. Once again this is another fungal disease. The worst part about it is the pathogen remains in the soil forever. You’ll most likely spot this on mature fruit that has a white, somewhat cotton-like looking, area on it. If this occurs, immediately bag and dispose of the fruit and the plants. Broad-spectrum fungicides do seem to be effective to some degree with this infection, but you have to be proactive. Unfortunately, once you notice an infection on the fruit itself, it’s too late to do anything. Remove and destroy everything. If you’ve had this issue in prior years, treat the plants throughout the season.

The challenges with this disease, besides remaining in the soil, are there are no resistant varieties, plus it infects other crops such as tomatoes, eggplants and peppers. I have to wonder if potatoes would be equally susceptible. Because of this you cannot plant these varieties in an area that suffered an infection in the previous year. And you might want to rethink the strategy for future years because of the prevalence of spores that remain in the soil. As you can see, this is a tough infection to fight. To stay on top of it, plant completely different crops where you had pumpkins or other cucurbits.

Many of us are at the point where we are ready to pick up pumpkins, or at least, it won’t be long. Even though it’s late in the season, keep an eye on those plants to make sure you have the perfect jack-o’-lantern for this year and for those Halloweens to come.