Ask Ed: Grow Tip – Removing Powdery Mildew

Suffering from powdery mildew? That’s that white, powdery growth on top of the leaves—it almost looks like flour—it can kill your plants. Here is the simplest way of getting rid of it:

– Go to your local garden shop, or nursery, and buy a bottle of potassium bicarbonate

– Mix an ounce of potassium bicarbonate in a gallon of water and 1.5 cups (12 oz, 340 grams) of milk—I prefer non fat, because it is less oily—but whole milk works as well.

– Spray on your plants or dip them in it. It kills the living fungus and the potassium bicarbonate creates an alkaline environment that hinders germination of spores.



  1. Anonymous on

    I am lactose intolerant. I can’t stand soy milk, but I do love Rice Milk. Off topic I know, but not only vegans like this stuff.

  2. Anonymous on

    Soy, almond, cannabis seed, rice milk & other non-conscious milk-forms all substitue animal milk perfectly: actually, they’re better (more morally obtained AND healthier).

  3. Anonymous on

    I take it from the ‘ha ha ha ha’ that it was meant as a joke.

    Plant don’t have central nervous systems, they are not conscious & thus can not feel pain. Everyone should be vegan.

    -soy milk substitues animal milk perfectly.

  4. haha on

    anon/may 19

    You are kind of a douchebag. I think others will agree with me. ^^

    His method explains how to rid the plant of the said affliction without removing any parts of the plant; so as to not cause harm to the patient, so to speak.

  5. Anonymous on

    C’mon buy some K-bicarbonate! Are you an idiot or just rich. First of all the only way to remove powdery mildew is to full it off by hand. By snapping the abcession layer causing auxin flow through the plant. Ok laymen terms just remove the infected leaves branches or flowers. It spreads by touch so be-aware. If your plant has enough lumens coming through your canopy and you do not water at night and there is plenty of air flow you will not get the mildew. But if you do just remove it dont spend your money just use your brains! Too many pot know it alls creates an economy just for problems their advice creates! just remember to have plenty of air flow and mildew will never be a problem. Research the topic through reliable means such as college educated botonists. Not some guys that claim to be the best and create a lot more problems and monocultured plants. Growing is very simple research how to grow and nutes your plants through reliable non drug related articles. Remember if they tell you to go out and spend money and it is in a pot magazine chances are it is bad advice. Peace through knowledge and anti-gov’t

  6. gloria on

    potassium bicarbonate, where do i get it?
    i keep being told to use it, but, not only me, but, my nursery man doesn’t know. i look it up and i can order 500 lbs of it.
    its really a problem for me.

  7. Anonymous on

    can you use this method while the plants are budding is it safe?

  8. ThinkingRationally on

    Aren’t you worried about murdering your plant when you harvest? Plants can feel pain too…. ha ha ha ha

  9. Anonymous on

    I am wondering if this is safe to use during flowering. I am about 3 weeks into flowering and see a hint of what looks like a powdery mildew infestation. I figure if I can nip it early I might save the crop.

  10. Craig on

    I don’t want to contribute to the suffering of animals. Being a Vegan I was wondering if one could use soy milk instead.