Powdery mildew on marijuana plants

Powdery mildew, also known as white powdery mildew, comes from lots of different fungi. Powdery mildew looks like white or gray powdery growths on the leaves of your cannabis plants.

It appears on grow areas indoors and outdoors and is foreshadowed by small bumps on the topsides of leaves. Typical species of fungi that go after hops will also go after your marijuana plants.

What is powdery mildew

Powdery mildew spores can be transported to your plants on the wind, through air ventilation systems, from pets, and any other living thing that moves (including yourself). Until the surrounding environment is ideal, the spores from mildew will stay dormant, biding their time.

What is powdery mildew cannabis
Powdery mildew on cannabis leaf

This is why powdery mildew on cannabis can be so tricky – you never know when it is lurking and waiting for the perfect time to strike. Powdery mildew is one of those conditions that is better to prevent from the get-go.

The main problem arises with powdery mildew when it is able to grow until it severely slows down photosynthesis and, therefore, ruins your harvest. It, therefore, needs to be taken care of as soon as you are able to identify it.

Powdery mildew is not as uncommon as some other conditions, so it is something that you need to keep an eye out for and to learn the effects of powdery mildew on humans.

If you want to make sure to get rid of powdery mildew, buy something like Bergman’s Plant Protector.

Marijuana plant protector

Bergman’s Plant Protector

  • Protect your plants from diseases and harmful pests.
  • Consists of three 20 ml bottles
  • Enough plant protection system supplies for up to 20 plants
  • Suitable for soil, hydroponic and all other grow mediums

Signs of powdery mildew on cannabis

You will know you have powdery mildew on cannabis when you notice fuzzy, flour-like circular patches on your marijuana plants’ leaves. You might see leaves that look spotted, mottled, and wilting. The powdery mildew infection will quickly spread to surrounding leaves and will “eat” everything in its path.

Powdery mildew is quite recognizable, given its stark white in contrast with the green leaves, and it can be removed if you use proper treatment in a timely manner. The problem with powdery mildew is the spores – often you can’t even see them as they are spreading throughout the air, making them extremely difficult to avoid and combat.

Powdery mildew on cannabis plants 360 view
Powdery mildew on cannabis plants 360 view

You can prevent mildew by having proper ventilation and the right temperature and humidity. If you still end up with mildew, you have to treat your plants.

Signs of powdery mildew weed
Signs of powdery mildew weed

Powdery mildew is the most likely to occur when humidity levels are high (above 55%) when there is not much air ventilation happening in your grow area. It also occurs when there is overcrowding of your marijuana plants at the grow site or in the grow room. Leaves touching other leaves are more likely to spread powdery mildew to each other, making it even harder to eradicate when your setup looks like that.

Powdery mildew generally goes for the youngest plants first, spreading across the entire plant and ruining the stems, buds, and leaves of your plant. You will notice a damp sort of smell coming from your buds – this is how you will know which buds have been affected by the powdery mildew as well as when you see a white powdery mold.

Once the fungus has invaded a bud, it cannot be taken away. If the powdery fungus continues its course of action, it will eventually make your marijuana plant turn yellow, which will become brown, and then the plant will simply die.

Also read: Leaf septoria on marijuana plants

It is crucial that you never let your plants reach this point. Make sure you are constantly inspecting your plants and always keeping a close eye out for any unexpected changes in your plants.

Not sure if your marijuana plants suffer from a powdery mildew infection? Check the article Marijuana diseases for a list with pictures of all possible marijuana diseases

Download my FREE marijuana grow bible and start growing high quality marijuana strains.

How to get rid of powdery mildew during flowering

There are some tricks to get rid of this irritating nuisance. But the best way will always be…

Avoiding a powdery mildew infection

If it’s possible, you should take certain steps to avoid an invasion of powdery mildew anyway. When you initially plant or transplant your cannabis plants into their mature location, make sure they have plenty of extra room. If they are planted closely together, the likelihood of powdery mildew popping up is significantly higher.

When you water your marijuana plants, you should make sure that you are doing it at a time of day when they will receive five hours or more of light after that. This can be artificial or natural light, depending on your growing situation.

You can also try using a UVC light if you are an indoor marijuana grower, which will keep any missed powdery mildew spores from going for your valuable plants. Some growers who have a few years’ experience under their belts might prune some of the fan leaves that don’t receive any direct light due to shading.

UV lights showing powdery mildew
UV lights

This makes it so there are less ideal spots for powdery mildew to land and begin growing. It also has the added benefit of your plant conserving its energy and using it more efficiently for other leaves and growths.

If you don’t want to see any issues arise in your grows, I might have a wonderful solution for you! I have created a balanced nutrient package, specifically engineered for growing marijuana plants! This will ensure that with your next grow you will have the best chance to get an amazing harvest!

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Treating powdery mildew spores:

If it’s possible, you should take certain steps to avoid an invasion of powdery mildew anyway. When you initially plant or transplant your plants into their mature location, make sure they have plenty of extra room. If they are planted closely together, the likelihood of powdery mildew popping up is significantly higher.

It can also be used preventatively before any powdery mildew arises at all. Another option is to do the same thing with one-half teaspoon of baking soda mixed with a quart of water.

Ingredients to create your own Powdery Mildew spray
Ingredients to create your own Powdery Mildew spray

Other options for destroying or preventing the powdery mildew include oil sprays such as neem oil, sesame oil, or fish oil. These sprays can also work well for other fungal diseases. A final option at your disposal is a milk spray made from 40% milk and 60% water.

This works so well because the milk has protein in it which reacts to the sun and naturally forms an antiseptic. This antiseptic is what kills the mildew. You can use a milk spray preventatively by spraying it on your plants every ten days, but only when the sun (or artificial light) is shining brightly. This is a common method for all gardeners to use on their plants.

Milk & Water spray to threat Powdery Mildew
Milk & Water spray to threat Powdery Mildew

In order to take care of a plant that has been infected with powdery mildew, you should utilize a plastic bag to remove the leaves that have been affected. Seal the bag and then put it into a disposal container that has a tight lid.

The reason for using the plastic bag is to prevent the spores from being sprung into the air and infecting other plants nearby. After removal of the infected areas, treat your plant with fungicide on the stems that held the removed leaves.

‘Plants are infected for weeks before they show the first symptoms.’

Jorge Cervantes

Other methods
There are a few alternative methods that you can use to heal your plants, including oil sprays such as cinnamon oil, garlic oil, coriander oil, clove oil, jojoba oil, or cottonseed oil sprays. A commercial product like Mold Control will always to the job. If you want to make sure to get rid of powdery mildew, buy something like Bergman’s Plant Protector.

There are also copper-based applications that you can purchase at any garden center. You can also try one tablespoon of hydrogen peroxide mixed in with water, which destroys the fungus by oxidizing its cell walls. Yet another solution is one teaspoon of limonene that is combined with one quart of water, offering fungicidal properties without actually killing the fungus altogether.

Finally, there are sulfur burners to control and contain the fungus. When using sulfur burners, make sure that you keep away from it when the treatment is taking place – in people, sulfur burners can cause respiratory inflammation. After the treatment, be sure to wipe off every window and wall completely so that you know any residue from the sulfur burner has been removed.

Want to hit the reset button and simply start over if your marijuana plants got infected by powdery mildew and were left untreated? I have created an all-in-one package including nutrients and plant protector which will give your plants the highest chance on survival!

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Powdery mildew plant symptoms

Leaf color, aka white powdery mildew

  • Pale colors
  • White patches on leaves

Leaf symptoms

  • Upper leaves and newer growths are affected
  • Lower leaves and older growths are affected
  • Visible white powdery patches on the leaves
  • Spots
  • Mottled, mosaic on leaves
  • Wilting and drooping of leaves

Plant symptoms

  • Mold

If you are looking for an extremely simple way to get rid of the powdery mildew, you should give the tap water – paper towel method a try. Simply get the paper towels wet and gently wipe your infected leaves with them, therefore removing the mildew that is already there. When doing this, make sure you don’t bump your leaves too much, as that could cause spores to enter the air and spread.

remove Powdery mildew with paper towel
Remove powdery mildew with a paper towel

You can also incorporate at least two fans into your marijuana grow room setup to improve the conditions and lessen the chances of powdery mildew development. You should have one fan directing air through the leaves of your plants and the other fan facing out from your grow room. This is so the “used” warm air is dispelled from the room and replaced with fresh air.

Powdery mildew destroyed your grow? Get new seeds from my seed bank

Remember that plants with strong genetics have less chance of getting sick and are less vulnerable to pests and diseases. So make sure to buy cannabis seeds from a trusted seed bank.

Know how to perfectly time your harvest so you can maximize your yield. Download our free mini harvesting guide

FAQ about powdery mildew cannabis

What are the powdery mildew health risks on cannabis?

If left untreated, powdery mildew will slow down your plant’s photosynthesis. You should take care of it as soon as you identify it so that it doesn’t ruin your harvest.

How to eliminate powdery mildew spores from buds?

Unfortunately, it’s not possible to remove powdery mildew from buds. Once it invades a bud, it will continue its course of action. Your marijuana plant will eventually turn yellow, then brown before it dies.

What are some examples of how to treat powdery mildew on cannabis?

People use oil sprays such as neem oil, garlic oil, and sesame oil, to mention a few. You can also purchase copper-based applications, sulfur burners, or buy products like Mold Control and Bergman’s Plant Protector.

If you’re looking to make your own spray or powdery mildew treatment, you can mix 40% milk and 60% water. Alternatively, you can create a solution using one tablespoon of hydrogen peroxide mixed in with water.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible.

Happy growing!


Download our free Ganja Livity lifestyle guide to learn more about rolling perfect joints!

Avatar for Robert Bergman

Robert Bergman


Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile

113 comments on “Powdery mildew on marijuana plants”

  1. One thing in here I did not see, powdery mildew won’t just turn the leaves yellow, it will kill the plant. it happened to me with one of mine and since I am relatively new to growing i had no idea that was what was wrong. i really thought the white powder were trichomes, boy was i wrong. i am glad i read this article. this current grow will not have this happen.

  2. Hey Bob, been a customer of yours for cpl yrs now. Ilgm is absolutely great. I have a question I was just reading and I have a powdery mildew on my plants and they’re just around the corner from harvest couple couple of of my pulled already they must have got stressed out and they butted right out to the Max I got some really big buds that’s some really big buds long story short I got a couple hanging and I’m noticing which wasn’t there before I’ve got white stuff on my buds and it wasn’t there before but I have white powdery s*** I know my other girls so the milk and water is the trick or a little bit of approxide and water will that get me around the corner to harvest season do you think I am probably 4 weeks ago From pulling my girls and I don’t wanna lose them because because I’m gonna have 10 to 15 pounds So I’m very nervous right now what shall I do

  3. Yep have This problem. Yep has slowed plant growth. Just sprayed with milk/water. Hoping it works. Other two plant near to bad one have no signs at all and growing great. So just hoping to save this one with a little milk and water. But only every 10 days. Wondering if can use Hydrogen Peroxide between those 10 days. But I’ll wait to see how things look tomorrow morning at watering time.

    • Hi there,

      Thanks for your comment! Sorry to hear this. Lets hope the mixture works to stop the powdery mildew!
      Keep us posted and let us know if you have any questions of course!

      Kind regards,

    • Powdery mildew can cause allergic reactions and potentially even airway infections. So make sure any buds you are going to use are free of powdery mildew. As long its just other areas of the plant that are affected, you could still use the buds. Its of course advised to treat any powdery mildew of course though, as it will affect your plants, and may spread to your buds.

  4. Have powdery mildew on some of my already harvested buds & one that is ready for harvesting.
    Bought an organic fungicide called Banish – is anyone familiar with it ?
    If I use on buds, will it hurt me to smoke them ?
    How about the onebI have not yet harvested ??

  5. You are a Legend Robert!!
    My main go to resource for any grow information I need
    I wish you shipped to south Africa
    I am making a long wish list for when you do
    Thank you

  6. Thanks. Great advice, however you mention using 1 teaspoon of hydrogen peroxide to treat mold? You don’t ever mention in your article how much water to mix with your 1 teaspoon of hydrogen peroxide? A gallon? Liter? Quart? Still have never gotten a straight answer?

  7. Robert, would you be interested in a fertilizer that buffers the water pH to 5.7-6.0? I have one it is a 20:10:16 blend with a buffer system. I am a soil and water chemist with extensive formulary experience.

  8. I used apple cider vinegar, tested some and there’s a bitter aftertaste. My plantzez are still potted so how can I treat them now to get rid of that taste? Spray the living buds with water?

  9. I am a 1st time outdoor grower and had pretty good luck until 4 days ago when I noticed very fain’t white blotches on some lower leaves.
    I freaked out and went to the local grow store and bought Organocide 3+1.
    I havent seen anymore white blotches but the smell of the fish oil they use is very concerning.
    Should I have not sprayed it on my plants 10 days before harvest?

  10. My plant is in the final two weeks of flowering and I’m noticing powdery mildew on the leaves. Is it safe to cut the leaves off….will it affect the buds? Looking for advice.

  11. WPM just hit new outside growers. We noticed a few spots on some of the larger fan leaves. We cut all fan leaves except small ones near buds and brought them in. We’ve watched it closely and after a few days we noticed a couple small spots show up on a couple of the remaining leaves, which we have also cut off. Is there something I can spray that is safe for buds to make sure it doesn’t spread further and ruin the plant? The hairs are curling and starting to turn brown and they are looking beautiful. I really don’t want those buds getting infected. 🙁 Any help is appreciated.

  12. I used the solution that was suggested in this article, the Powdery Mildew Spray of 1 Gallon H20, 1 tbsp Baking Soda, 1 tbsp Liquid Soap, 2 tbsp veg oil. A day after I had done this the plants looked fine but then three days further after treatment one of my girls has started to show some serious problems. All of the leaves are starting to dry up and curl even near the top. What happened and any suggestions on what to do? I am in week 5 of flowering.

  13. I had a bad infestation of the powder mildew. Tried other methods to get it under control with no real results. Saw ur comments on using milk and water. Saw immediate results overnight! Amazing !!

  14. On the white mold, I have had a small bit of it. I tried baking soda, but was not sure if it is to be applied with in the ground watering or to be applied by spray bottle? Some of the other applications on this appear to be unclear, as well, which I may try if the baking soda doesn’t work.

  15. Hi so we have recently noticed some of this powdery mildew on the leave . My plants are a week or less from harvest. An unfortunately I think we have noticed this to late. Is there anything we can do to get rid of it. Since I believe it is in the bud. I don’t think it is a good idea to smoke it by the comments above. But has anyone tried Used the product In ice water hash method so the product don’t go to waste?

  16. This article has been very Helpful, to this first time grower, in Oklahoma! I’ve noticed a white powdery substance on the outside of my hydroponic buckets….when I touch it the texture is grainy, like sand. Almost like mineral build up. I clean the outside of the pot with aCV soaked plant based paper towel. Is this white mold? Or something different? However, I do not see a white powdery substance on the leaves. I’ve learned alot today from this comment section. THANKYOU!! I will be proactive and spay weekly with acv!!!

  17. Hello there
    I would like use milk&water for my plants. Indoor i have to spray them when lights are off or could i spray when they on? Thank you

  18. Is it better to spray your plants with hydrogen perixide solution to kill powder mildue in the day light hours or can i spray them on there sleep cycle

  19. Milk doesn’t work. Bicarbonate products can work, but can be hard on foliage if used to frequently. Vinegar is hard on leaves too. You’ll find recipes for using it as an herbicide all over the internet. It is not an effective herbicide though, even undiluted, and burns the shit out of your nostrils. Essential oils and horticultural oils will knock down PM. Don’t spray these more than once a week or use at all if you’ve recently used sulfur or plan on using sulfur. Preventing PM is your best option. Under ideal conditions it only takes a couple of days for a spore to germinate and infect a plant. Sulfur burner work great in preventing the disease if used daily, only it is illegal and you might get asthma from it like I did. There is a potassium sorbate product that binds the potassium sorbate to carrageenan (All Phase). It is cheap enough to where you can spray it every two to three days. That works as well as sulfur, but you have to spray it. You could probably have a fogger on a timer and Apply it that way. Indoor conditions are generally more favorable for PM. Outdoors you Generally have highest pressure in spring. I don’t plant until mid-June to get by the worst of the disease pressure. Plants still end up over six feet by the time of fall harvest.

  20. I seem to have powdery mildo on only one plant in my garden. It was a different strain, and added weeks after the rest of my plants. Can I treat this single plant . And let it keep going? Or should I just remove it, as my other plants don’t look to be infected. And they are all budding nicely

  21. Car, I Suggest You Go Here: Support.Ilovegrowingmarijuana.Com Our Members And Staff Can Help Give You Informed Advice. We Have A Lot Of Topics That You Can Research.

  22. Thank You for all if the Informattion on powdery mildew. Im growing with someone else in a greenhouse and she doesn’t have the humidity under control at all. And though she just planted her Plants 2 weeks ago they are Showing signs of powdery mildew already. So I Just removed my Plants from Inside the greenhouse i dont
    Want anytbing to do with that stuff…lol! Thanks again

  23. I wouldn’t spray milk on your buds. Milk is too perfect of a medium for molds to thrive in. There are some safe and effective products out there that can eliminate your PM and keep your other pathogens at bay. Look for products with potassium sorbate. Potassium sorbate is the most commonly used food preservative used in the world, so you know it works on a wide variety of bacteria and fungi and it is safe for you to eat and smoke. A couple of products that have it are Dr. Zymes Eliminator and All Phase. It is best to prevent powdery mildew than to wait until you have it. The UC IPM website has good information for dealing with pM that is backed by science.

  24. Hello there i am in Last two weeks of my plants and i got this problem with powdery mildew and its spearding around fast what is quick action for it to fix it without harming my buds plz help and plz let me how much its harmfull for my buds in this stage . Thanks

    • Charlie, I suggest you go to our forum for the fastest support and ability to discuss your situation and what may have caused you issue. Go here: support.ilovegrowingmarijuana.com. See you there 🙂

    • Benny, that would be what I call “touch and go”… When spraying anything on buds late in flower it is possible to create mold or a rot issue. Best I can say is; It is not worth anything with powdery mildew all over it, so try it and take notes to share.

  25. Just completed a outdoor grow with-mixed results, trending toward failure – Bud Rot due to a span of heavy rains, high heat and humidity, resulted in loss of half of plants. Salvaged what I could; noticed the bud is fluffy, not compact (I figure due to high heat, day and night). Next grow will be stealth, indoor

  26. First of all thanks for helping us out, I’m in my 6th week of indoor grow and now this pops up! Will my foliar spraying the leaves and buds with the vinegar solution take away from my final product this far along? I only have 2-3 weeks left or would I be better to just wipe the leaves down with the vinegar solution? Thanks, ahead of time!

  27. hi guys first time growing in a small hoop house .10 x 16 with only 6 plants.2 fans on the plants. just notice what i think is powdery mildew. how often do i spray with the ACV ? my girls are about 30 inches tall with just a couple of the lower leaves infected . how long will it take to see results

  28. This is no different than what is seen on grapes and wheat. Powdery mildew is most prevalent on lower leaves but can cause blighting of the upper leaves, heads and awns of susceptible cultivars. Within a few days after they appear, the white powdery pustules produce large quantities of small asexually produced conidia (also called oidia) in long chains, which are easily dislodged by wind or rain. These spores are single-celled, oval (8 to 35 µm) and colorless. As lesions age, the mycelium becomes more dense and turns grey (Wiese, 1987). Dark round cleistothecia (135 to 280 µm in diameter) develop in the fungal mass as the pustules get older. Ascospores develop in the cleistothecia and serve as the long-term survival structures. Cleistothecia may be empty if examined when plants are harvested because ascospores often do not mature for several months.

    I would venture to say that there is little to no particulate recirculation filtration in these rooms. Considering the spores are 8-35 um, a MERV 13A or 14A particulate would eliminate this problem completely.

    • May have been obvious, but I should have clarified that a recirculated air filter solution is for indoor growing only.

  29. 1doug,

    Yes, UVC lights are known to a lot of growers, especialyl growers that are always adapting to newer ideas and products.

  30. We had limited success with sprays and home remedies at best. Nothing seems to really work so great.
    We found a place to buy a couple of UVC lights and tried it on a small section of our grow. It worked better than expected, and plan to purchase more, but was wondering if anyone has ever heard of these ?

  31. ACTINOVATE !!! It’s all I use for mold, and fungus issues ! Root drench every 10 days, foliar spray once a week. It will control existing mold, but prevents it completely if used before flowering ever starts. Pricey, but nothing but the best for my girls !!

  32. IN MY OPINION THE MILK AND WATER DOESNT WORK iv did this last year and it went away for a couple days but came right back quick…but the slufer burners work awsome and so does the organic apple cider vinegar and water

    • Milk curtails the growth of the spores, and must be reapplied every few days as you proved here. You cannot just treat an issue once and hope that is all you need to do. This type issue requires diligence. I like the Sulfur burners myself as mentioned, also.

  33. I’ve been growing for over 35 years. It’s basically farming and you learn something new each and every year. The tips you have here are sensible and easily understood. Nobody knows it all and your guide sure helps…thanx.

  34. I have never gone pot for myself or commercially but have serviced many growers.
    With the issue of air born mold spores/and or mycotoxins I have developed an air scrubber with the ability to turn 660 cfm of purified air. Oxidizing any anaerobic organism along with the mycotoxins. Each unit large or small has this same ability. Many folks have purchased theses units not for growing but in the “cleaning the air” from pot smoke.
    For growing you can also spray a colloidal solution or tio2 on any surface and the chemistry will also oxidize any organic odor or mold spore.

  35. Hi, we have had a lot of success with the DragonJuice PM2 from Completely Organic. It’s an organic, non-gmo, toxic plant extract blend and PM fall off immediately and no toxicity to plant or quality of bud. In fact, gets rid of mold right in front of your eyes with immediate spray. Controls mold in 2 days. Plants healthier, higher brix and THC. Great tasting bud! Dragonjuice.org

  36. I have been using a product called CU H2O this is been working real well for me better than anything else that I’ve tried it is a natural product and that’s what I like about it.6 month now greater looking plants happy

    • I left a post here a couple months back about powdery mildew and I found a product called CU H2O I have been using this as a preventative and for the first time in 6 years ago and I have had no issues with powdery mildew at all very happy I also used it on my outdoor Garden this year with tomatoes and squash and it worked excellent

  37. […] You can recognize powdery mildew by its white color. It will cover the foliage of the plant and inhibit the photosynthesis process. If your plants suffer from powdery mildew, there are a number of safe naturally based sprays you can use (including milk and apple cider vinegar) to help deal with the problem. Mold control also treat powdery mildew. Read more about Powdery mildew on marijuana plants […]

  38. Great site! I don’t really smoke the stuff but have enjoyed growing it a few times. I live in a small coastal town so fog has always been my enemy, and the dreaded nasty caterpillars!! UGG Since we no longer have an ozone layer to protect us, our summers have been much warmer. 3 girls did Fantastic! I picked bugs, never sprayed even though there are (Safe Caterpillar Killers I have read about. One plant finished beautifully but my last 2 Fab girls broke out with mildew even with ideal hot outdoor conditions. First I used a wet paper towel and wiped off what I could and pinched off where it was easy with latex gloves being careful not to spread spores. Then I used this sites recommended 2 tsp of Apple Cider Vinegar in a quart spray bottle. I sprayed only affected areas 2 hours before the sun went down last night. This morning 2 hours before the sun started blaring I sprayed the leaves and buds (only 1-2 weeks to finish line) and presto, magic, it is all gone! Timing was good. I don’t think you should spray right before dark as bud rot may occur but this simple organic vinegar and water did the job! Good luck and thanks for this info, it was perfecto!

  39. I used some garlic water early on and hit the PM right away at first tiny sign on my outdoor. Now…they are budding beautifully, and I noticed one tiny spot today. Is it ok to use the ACV or Garlic water while it’s budding w/o affecting the buds?

    Thank you!

    • This is one of those judgement calls. You are the best one to make this decision. You are there, and used this solution already. As with anything added, especially home type remedies; One must exercise good judgement and caution.

      Feel free to join our support forum. We have many growers from around the world will to help you grow successfully.

    • Can I ask why?

      I would be wary of spraying vinegar water on my plants because, that is acidic, and could harm the plant if not done with the utmost of care.

      Please join our ILGM Support Forum for more opinions and expert advice. 🙂

      • ACV and Milk combo. 2tbls ACV and 1/4 cup of milk to one gallon tap water in Co. Basement grow. Sprayed with 5 hours of light as recommended for use with milk. I had bad PM covering 70% of 4week budings. I was afraid to treat so I let it go until I had no option. 3days after treatment all PM gone and buds unaffected, maybe even healthier than my last grow. Now I use it as a preventative measure on my veg and before cloning. Don’t tell my husband though he thinks he knows it All, jking, lol.

      • It had no affect on the taste either I am in week 6 flower totally devastated it’s my 1st grow hoping I can wipe and clean

      • Hi Housewife Grower. Did this work? When you say 5 hours. Is that after the lights have been on for 5 hours or when they have 5 hours to go before they turn off? Thanks in advance!

  40. […] You can recognize powdery mildew by its white color. It will cover the foliage of the plant and inhibit the photosynthesis process. If your plants suffer from powdery mildew, there are a number of safe naturally based sprays you can use (including milk and apple cider vinegar) to help deal with the problem. Mold control also treat powdery mildew. Read more about Powdery mildew on marijuana plants […]

  41. One thing that worked for me in a greenhouse with squash plants is one tablespoon of baking soda in a gallon of water. For more extensive treatment try using potassium bicarbonate as potassium is a plant nutrient and does not have sodium in it. Sodium bicarbonate works because most fungi do not like an alkaline environment and the bicarbonate is just alkaline enough to inhibit the fungus.
    Wish you luck.
    Bill Graves
    Agricultural and Horticultural Consultant
    Homestead, Fl

    • I too use this method of Baking Soda to combat Powdery Mildew, mold. Baking Soda is highly alkaline. Mildew cannot thrive in such an alkaline environment.

      A friend of mine in the Carolina’s likes to spray diluted milk to combat mildew; I tis gentler than Baking Soda; IN his opinion.

  42. to always give myself the best chances of not getting powdery mildew I clean my whole grow room with this stuff called Grow Clean. had PM once before this stuff!! introduced grow clean and bam! never saw it again

  43. powdery mildew specifically does not contain or release harmful mycotoxins found in most mold/fungi species. In short, although disgusting to the palate and may cause a vomit reaction If smoked, powdery mildew unlike other molds, is safe. Don’t take my word for it tho, at very least google what I said and confirm it. Prevention is the best cure. never vend pm covered meds., ever.

  44. What is the scientific name for the Powdery Mildew I have someone that had an attack from the mold needs to know. Thank you ƒg

  45. Can I smoke buds that had power mildew. I’ve taken off fan leaves and sprayed plant with clear water,I’m flushing the plant to harvest them. Thanks Jett

    • You could get very sick from smoking mold in your buds. It doesn’t go away with drying, it is compressed tight inside your buds. People with respitory issues or even a healthy person can be affected. When you smoke moldy buds, you’re ingesting it, not good my friends.

    • On the white mold, I have had a small bit of it. I tried baking soda, but was not sure if it is to be applied with in the ground watering or to be applied by spray bottle? Some of the other applications on this appear to be unclear, as well, which I may try if the baking soda doesn’t work.