How to Organically Control Powdery Mildew

By on June 30, 2011

In this video, Tricia shares her tips on controlling powdery mildew, organically!

  Comments (13)


As an organic grower on the west coast of the Pacific coast of Mexico, powdery miildew is a constant problem regardless of the season due to the average temp 80 degrees and humidity from the jungles. Those of us planting out of the U.S. do not have access to your recommended products,  However, we use 1 part raw milk to 9 parts water, sprayed every 6-8 days not only gets rid of the white mildew, it also prevents further development.  We spray for a 4 week term, twice a year.

Posted by Krystal Frost on Jul. 01, 2011 at 12:22:40 PM

I spray an organic oil on my apple trees in the dormant season as well as summer to protect against powerdy mildew.
Although I purchase some from you, I was wondering if purchasing gallons of either vegetable, corn, canola, or soybean oil purchased locally would do the same as the Stylet or other OMRI listed oils I currently purchase?

Posted by Rich Ever on Jul. 05, 2011 at 7:00:11 PM

Krystal, Thanks for sharing your tip!

Posted by on Jul. 07, 2011 at 11:19:15 AM

Rich, Stylet contains parafinnic oil, Saf T Side has petroleum oil, and Organocide is a combination of fish and sesame oil. It’s important to use the horticultural oil products only for their labeled purposes.

Posted by on Jul. 07, 2011 at 11:47:49 AM


I’m sure the best for you to your friends   for more detail

Posted by uncokouida on Dec. 29, 2011 at 12:25:26 PM


Since fungicides are detrimental to mycorrhizae, it seems counter-productive to apply compost tea and then spray something that kills the very organisms you are trying to build up in your soil.

Posted by Kit V on Jul. 29, 2015 at 12:43:52 PM


WD40 is said to be made from fish oil.  Might it work as a fungicide?

Posted by smithson on Jul. 30, 2015 at 1:28:09 PM


I have powdery mildew on my goji berry plant.  I am not sure what I should use on it.  The whole plant is covered in it.

Posted by Kimberly C on Jun. 03, 2016 at 5:18:34 PM


I have used potassium bicarbonate effectively on my cherry trees and squash plants. It can be purchased at wine and beer making stores. Mix 1 tablespoon per gallon and spray on the plants.

Posted by Harold on Jul. 21, 2016 at 5:55:30 AM


How do you get rid of knats(small flys)?  Does it come from the soil and what can I do to prevent this in the future? Use a different organic soil or oils?
thank you for your response.

Posted by Emiko on Jul. 22, 2016 at 5:15:48 PM


Emiko, if these are fungus gnats, then they reproduce in the soil. There are many ways to get rid of them. You can do a search on our website for fungus gnats for help in finding products for controlling them.

Posted by Suzanne on Jul. 25, 2016 at 12:30:26 PM


WD-40 is petroleum based. I wouldn’t use it in a garden, or on something that people may come in contact with.

Posted by gene on Aug. 23, 2016 at 8:26:18 AM


WD-40 is petroleum based. I wouldn’t use it in a garden or in especially.situations where it may be ingested

Posted by gene maxim on Aug. 23, 2016 at 8:29:56 AM

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