Problems With Acorn Squash Diseases?

Fortunately, acorn squash diseases are usually not a problem. In fact, many hybrid varieties of acorn squash have been bred to be disease resistant. However, acorn squash plant problems do occur. In most cases, these problems in your squash patch are insect related.

Most acorn squash "diseases" are caused by three main insects:

  • Squash Bugs
  • Cucumber Beetles
  • Vine Borers

Squash bugs are a common pest, and can cause acorn squash diseases. They are usually gray or brown in color, although some are almost black. Squash bugs are usually about the size of a dime and travel in packs. They will suck the juices from the plant and will actually attack the squash itself, although they usually lay their eggs on the underside of the leaves.



Acorn Squash Seedling

It's easier to prevent a squash bug problem than cure it. Many of the same products that prevent vine borers and cucumber beetles will also prevent squash bug infestations. You can begin spraying soon after the seedlings emerge. By the time the blossoms appear and the plants begin to set fruit, you should have the problem under control. Most of these insecticides are available at most garden centers and should be applied according to the manufacturer's instructions. If you are trying to grow organically, there are soap sprays and other organic sprays available at most garden shops. Be sure to also keep your garden free of weeds and other plant debris. You can also cover the stems of the plants with cardboard tubes to discourage pests.



The most common acorn squash problems are caused by cucumber beetles. The striped cucumber beetle has black and yellow spots on its back. The spotted cucumber beetle has a yellow back with black spots. They love to chew on young acorn squash leaves and stems. Cucumber beetles also carry wilt diseases from plant to plant. Fortunately, these pests can be controlled with common insecticides including sprays and dust. Diazinon and Malathion are common chemicals that will kill cucumber beetles. Apply products that contain these pesticides according to the manufacturer's instructions. Most can be applied soon after the seedlings emerge and throughout the growing season. Organic products including soap sprays are also available at most garden centers.

Baby Acorn Squash

Vine borers are a common garden pest and can do some serious damage. They will attack any summer or winter squash plant, along with cucumbers and pumpkins. They will bore into the main stems at the base of your acorn squash plants, sucking out the juices and eating the plants themselves. Once inside the stems, they will continue eating away at your plants from the inside out. Many times this damage is not noticed until significant and irreversible damage has already been done. The squash growth will suddenly slow and the plant will wilt, shrivel and die. Many backyard vegetable gardeners see the plant wilting and assume that the problem is lack of water. If the plants continue to wilt after a thorough soaking, you're definitely battling vine borers. You will also notice something that resembles a small pile of sawdust at the base of your plants. There are several products on the market that will prevent vine borer infestation. It's important to apply these products before your acorn squash plants become infested. Read the labels on products that contain Diazinon to make sure that the spray is effective against squash vine borers. Follow the manufacturers directions. Most of these insecticides can be applied soon after the seedlings first emerge. Once the plants stay consistently wilted, you've probably lost the battle. At this point, it's best to pull the plants out of the garden and start over by planting more seeds.



If you've ruled out insect problems, you may actually be facing problems with acorn squash diseases. Some diseases that affect squash plants are wilt disease, powdery mildew, downy mildew and scab disease. These are usually identified by a powder like substance on the leaves or stems. There may also be visible black spots or splotches on the leaves themselves. Most acorn squash diseases can be avoided by choosing disease resistance varieties. They can also be controlled with soap sprays or fungicides that are usually available at most garden centers.

Remember, when dealing with most garden pests and diseases, "an ounce of prevention is worth a pound of cure". We hope these tips will help you to avoid most acorn squash diseases.

Click on the following links to learn more about growing acorn squash.

Acorn Squash On Vine

Click here to learn about planting acorn squash

Click here for information about watering and fertilizing acorn squash plants

Click here to learn about harvesting acorn squash

Click here for some of our favorite acorn squash recipes

Click here to move from our Acorn Squash Diseases page to our Growing Acorn Squash main page

Click here to return to our Home page