Hello Annie,

My cucumber plants look like they have some kind of white growth on some of the leaves.  Is this what they call powdery mildew and what can I do?

Thanks for any help,

Antoinette G. 

Hi Antoinette!

Thanks for the question.  I will try to help if I can.

It surely sounds to me that it's powdery mildew affecting your plants.  

Powdery mildew causes a white powdery growth on the leaves and stems of your cucumber plants.  As the disease progresses,  the infected parts will turn yellow, shrivel and lose their foliage.  

This disease is more prevalent in humid weather with frequent dew and temperatures between 70 and 90 degree

Stating in your email that you've seen white spots on only the some of the leaves,  it appears to me that the disease is in it's early stages.   You may be able to save them by using a fungicide treatment purchased at your local garden center, or you can may make one yourself, by using a couple of teaspoons of baking soda per gallon of water.   Apply the home-made solution with a watering can,  during the day.  

If this doesn't help,  you will then have pull out and destroy the cucumber plants.   You may have enough time in your region to replant some new seeds,  but do so in a different location.

When planting cucumbers make sure you have enough of the proper spacing, air circulation, correct watering and alot of sun, which helps to alleviate  disease problems.

Also, vining cucumbers varieties do perform better when growing on trellises than they do growing across the ground.  They get better air circulation and this leads to fewer disease and insect problems, and more production.

In the future,  you may want to try to plant disease resistant cucumber varieties such as Burpless Tasty Green F1, Slice King F1, Media F1, Salad Bush or Marketmore 76.   Marketmore 76 variety is what I grow in my garden.

Hope that helps!

Keep on gardening!

Annie~