Squash Troubleshooting

squash troubleshooting garden

Winter squash suffer from several common problems. If left untreated, these problems can affect the quality of your winter squash. The following is a list of the most common problems associated with winter squash and how to deal with them:

  • Gummy Stem Blight (Black Rot): This is a fungal disease that can affect the stems and leaves of your winter squash. It can also spread to the fruits.Solution: Use a soaker hose or drip irrigation and give your plants plenty of space.
  • Downy mildew: This disease attacks most of the plants among the cucurbits. It is caused by the fungus Pseudoperonospora cubensis. If temperatures are cooler and conditions are moist in your region, your squash plants may be at risk. Early signs are yellowing spots on the leaves that may turn brown and fuzzy with time. As the disease progresses, the patches will turn black.Solution: Give your squash plenty of room to breathe so that air can circulate. Use a compost tea if you expect long periods of cold, wet weather. Ask you nursery about disease-resistant varieties of winter squash.
  • Powdery Mildew: Look for a white mold on the leaves of your squash plants. This disease is caused by several different kinds of fungi and will eventually kill the foliage and can affect squash fruit. Powdery mildew occurs in warm rather than cold conditions and high moisture levels will make the problem worse.Solution: Keep your squash foliage dry. Drip irrigation can help. Compost teas also help to treat this problem. Another organic solution is to apply a mixture of baking soda and water to the foliage (less than an ounce of baking soda per gallon of water). Remove garden debris after you harvest all garden plants.
  • Cucumber beetles: Cucumber beetles affect many plants of the cucurbits. They can attack at any point in the growing season. Look for these pests on the fruits and on the vines.Solution: To treat your winter squash organically, use thick organic mulch, which can keep these pests from laying their eggs. Plastic mulches can also deter their presence. It’s also important to remove garden debris during and after the growing season.
  • Squash bugs: Squash bugs are a common problem for cucurbits. The can be a problem throughout the growing season and they canaffect both fruits and foliage.Solution: Companion planting is an effective solution to squash bugs. Mint, catnip, nasturtiums, and marigolds are excellent companion plants that help repel squash bugs. You can also remove squash bugs by hand. Another unusual option is to encourage the presence of the parasitic wasp Ooencyrtus (spp.) in your garden.
  • Other common problems: Winter squash are also threatened by the squash vine borer, the pickleworm, and the seed corn maggot.Solution: There are a variety of options to treat these pests. See this site for more organic pest control methods.

{ 9 comments… read them below or add one }

Marina April 14, 2010 at 12:32 am

My squash is just starting to bloom and I notice the first three of squash that the flowers have fallen off are starting to shrivel up. What’s up?


Bruce May 27, 2010 at 2:32 am

@Marina, I have the same problem. The squash fruit stops growing, kind of shrivels and then detaches from the stem. I’d appreciate a troubleshooter advising me what I’m doing wrong.


DaggerD July 8, 2011 at 5:24 am

They didn’t get pollinated. If you don’t have insects that will pollinate your squash, they are really easy to do by hand. Just pick a male blossom (the one with a stamen) and take the leaves off. Rub the pollen laden stamen on the stigma (female version of the stamen-connected to the small fruit). When they get pollinated they grow, if not, they shrivel and fall off.


Michelle May 25, 2010 at 1:42 am

I have powdery mildew onspeghetti squash. I just treated the plants with the baking soda/water solution. How often do i do this? Should I stop watering for a few days? Should I see improvement in a few days?

Thank you!


Skip June 9, 2010 at 11:46 pm

My yellow summer squash is producing nicely. Some of the squash are nice and smooth and some are quite knobby. The latter tend to be pithy inside and sometimes even hollow. Why is the same plant producing two different squash?


Cheryl August 16, 2010 at 8:27 pm

I am having the same kind of issues Marina and Bruce! The flowers on my squash turn black and then the squash shrivels up. I had someone tell me to leave the squash on the plant to let it keep growing, but it is getting worse! Help!


Loretta July 27, 2011 at 7:39 pm

My yellow squash have grown to about 8″but are as hard as rocks, like acorn squash. They are perfect in look, no spotting, what’s wrong?


Sheila August 4, 2011 at 1:32 pm

Acorn squash – table ace

Hi. I’ve planted table ace acorn squash from seed. The plant is doing well and has lots of squash. The problem is that they are large, oblong, yellow and deflated. There are about 6 squash like this. On the end of one of the vines is a normal green table ace squash. What would cause this deformation? They are about 10 inches long looking like a partially inflated punching balloon. Should I continue to let them grow? They were planted in May from seed. This is my first year gardening.



winter squash September 5, 2011 at 7:53 am

my plants have been growing well now for 3 months lots of blooms but no fruit have set is this normal


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