Powdery mildew.

I have powdery mildew on my sweetpeas and there are a lot of other plants nearby . I treated it with a fungicidal spray but then read of an alternative method using baking soda . Has anyone tried this and if so does it work ? I like the idea as I don't like using sprays etc . I also read that p. mildew hates water so would like to hear your comments or any other ideas on how to get rid of it.

Thanks , Jean.


  • ItalophileItalophile Posts: 1,647

    Jean, a baking soda-based spray is commonly used against powdery mildew. Give it a try.

  • LilylouiseLilylouise Posts: 1,014

    Jean - I used a milk and water spray on my Cues in the greenhouse and it did help image

    Pam x

  • Jean GenieJean Genie Posts: 1,724

    Thanks for your help - I shall try both methods .


  • How much baking soda do you use?

  • Apparently (I have no personal experience of this) you use 1 tablespoon of baking soda and half a teaspoon of washing up liquid to a gallon of water.

    You should water the plants a day  or so ahead of spraying them with this and use caution (test a bit) as it can sometimes burn the leaves. Avoid doing it in bright sunlight. Apply to top and bottom of leaf.

    you can also add 1 tablespoon of horticultural oil, which smothers the fungus.

    I found this on About.com (Gardening).

  • Pottie PamPottie Pam Posts: 887

    I've been spraying a clematis that was showing signs of powdery mildew. I've used milk and water and it really seems to be working.

  • how much milk do you use as I have mildew on my viola. Can you use cream??

    these plants are outside in deeproot trainers 


  • I used about a tenth of milk to water but the clematis did succomb in the end. Perhaps I didn't start the treatment early enough. I think cream would be okay. I think it's the lactic acid in milk  that affects the mildew.

    I've planted some viola this year but haven't for a few years as in the past they've been affected by some sort of virus that causes black spots on the leaves and they eventually died

  • I'm going to water my plants first and them tomorrow spray them 


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