Problems in the pumpkin patch? Pumpkin plant diseases can put paid to the months of hard work you have put into growing them, but do not despair!

If caught early enough many of these diseases can be spotted and treated with minimal hassle. We'll also take a look at which diseases can be prevented as we go along.

Bacterial Wilt

Bacterial wilt is one of the most common diseases a pumpkin plant can suffer from:Pumpkin patch(100371)Credit:

How to Spot: Wilting and browning on leaves of the plant. Best spotted in the day - it can look less wilted at night. It's easy to confuse with wilting from lack of water, so perform a small test to determine the cause - cut one leaf from the plant, about an inch from the vine. If the sap that comes out of the leaf is yellow and stringy, then your pumpkin plant definitely has bacterial wilt.

How to Treat: Unfortunately there is no known remedy for the problem other than removing the diseased plant immediately, to prevent it spreading to other plants in your pumpkin patch. Do not compost.

Prevention: It's best to try and prevent the disease as there's no cure once it's caught hold. Regular spraying of a fungicide will help, as will watering only the vines and roots not the leaves, as excess moisture promotes disease.

Cucumber Mosaic Virus

Cucumber mosaic virus isn't exclusive to cucumbers, pumpkin plants can also be victims, and it's a definite disease to look out for when growing butternut squash and melon too. There are also other cucurbit mosaic viruses that can affect pumpkins, but signs and treatment are the same.Cucumber Mosaic Virus

How to Spot: Mosaic style pattern on leaves (pictured).

How to Treat: There is no cure for the virus other than disposal so it won't affect any other plants. You should also thoroughly clean and disinfect any tools, work surfaces and hands to prevent the virus spreading.

Prevention: Cucumber beetles and squash beetles are the main culprits for spreading viruses to pumpkins so try to keep them at bay. Also try to plant earlier in the season, rather than later as these tend to be less disease prone.

Powdery Mildew

Powdery mildew on a leafCredit: mildew on pumpkins is one of the most common pumpkin plant diseases to look out for.

How to Spot: Powdery white mildew appears on plant leaves.

How to Treat: Fungicides can be used to control the disease, even before symptoms reveal themselves. As it thrives in hot and humid weather, you should definitely spray your patch during these times. It can spread quickly, so fast action is recommended. There is also an easy organic treatment for white fungus (another name for powdery mildew), that you can make yourself.

Sclerotinia Rot

Sclerotinia fungus affects tomatoes, beans, carrots as well as the cucurbit family.

How to Spot: White mold appears on fruit and plant vines, black lumps (watermelon seed size) appear among the mold.

How to Treat: The use of a fungicide on young plants may be effective.

Prevention: Damage to future pumpkin crops can be minimized by using the patch for a different crop type (that is resistant to this rot) for a few seasons.

Other Pumpkin Diseases

There are, of course, other diseases that can infect pumpkin plants, but these are less common:

  • Phytophthora Blight (fungal) - white colored soft rot appears on pumpkin fruit.
  • Microdochium Blight (fungal) - white, green or tan color lesions appear on leaves and pumpkin fruit.
  • Fusarium Crown & Fruit Rot (fungal) - first sign is yellowing of plant, followed by plant wilt, collapse and decay within 2-4 weeks. Grey and white mold on fruit may also appear.
  • Black Rot (fungal) - irregular tan lesions, often exude orange/brown gummy substance. Black fungal spots on fruit.
  • Bacterial Fruit Spot (bacterial) - tan scabs appearing in clusters on the fruit. In the main, fungal diseases can be treated with fungicides if they are caught early enough but prevention is best. Humid conditions and bad air flow, make fungal and bacterial disease spread, so water at night, avoid watering leaves, and ensure your plant has room to breathe - i.e. there aren't other plants crowding it.

There is little, to no treatment, for viral and bacterial diseases once they have taken hold, so try to clear the area, and disinfect all tools that have come into contact with the diseased plant to prevent it spreading too. The most important rule is not to compost diseased plants or the cycle will continue; you can at least protect future crops if nothing else.

Now you know what pumpkin plant diseases to prevent, look out for, and treat, you will have a pumpkin patch from which to choose only the best specimens to make pies and the best looking jack-o-lanterns for frugal Halloween decorating.