Monday, August 16, 2010

Pumpkin and squash mildew kills plants.

Powdery mildew, a common problem of roses, turfgrass and many other plants, also is a problem for squash and pumpkin especially when we experience the cool, humid conditions of fall.

This fungal disease destroys the photosynthetic ability of the leaves reducing the quality, size and yield of the fruit. 

The first syptoms you will see are white spots on the leaves.  These spots increase and eventually cover the leaf. This disease reduces the sugars and starches necessary for the development and sizing of the fruit.

Controlling this disease is quite easy if you use the correct product or combination of materials.  Some people use SunLite oil in combination with baking soda as a spray.  A better product to use is potassium bicarbonate.  Baking soda can damage plant cells; potassium bicarbonate is much softer in its activity.  Neem oil is also reported to be an effective control of powdery mildew.  Your local nursery or garden center should have one of these products on their shelves.

These products are best applied in the evening as they remain in the liquid state for a longer period of time.  If a rain occurs shortly after you make the application you will most likely need to reapply the product.  You will still see spots on the leaves even after you treat for this disease, but as long as the spots don't enlarge or more spots don't develop, the infection has been stopped.  Follow the label to ensure you apply these at the proper dilution and frequency.


  1. This always happens my cucumber plants and courgettes. Thanks for the tips.

  2. One effective way to combat mildew problems is by the use of desiccants like Silica Gel. These are the same small sachets you find in packaging of various products like electronics, garments, etc.

    Silica Gel works by absorbing the moisture in its surrounding area. For most mildew challenges, it does the job pretty well. Small sachets cost less than a dollar. It truly is a cost effective way of protection from moisture.

    There is a lot more information on our website at

  3. i wouldn't want to use poison on mine mine gets that stuff every year i think in June or July is when i notice it on the plants but where is it coming from maybe it comes from the rotten leaves i have around the flower plants>

    >i cut a leaf off & looked at it under the microscope i have and it looks like just white mold and the plants haven't been making any flowers for a few years now they make the flower head but wont open up dish-soap doesn't help the flower plants that i have it doesn't kill the mold.

    1. Have you ever heard of a period or a comma? How about capitalization? Good grief!

  4. what other ways do you know of killing this shit

  5. Just the info I was looking for, thanks for the tips!