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.
- What is powdery mildew
- What is Powdery Mildew?
- Signs of Powdery Mildew on Cannabis
- How to Eliminate Powdery Mildew During Flowering
- Powdery Mildew Plant Symptoms
- FAQ about Powdery Mildew on Cannabis
- Frequently Asked Questions
- What can you do to effectively treat powdery mildew on plants?
- How can you recognize powdery mildew symptoms?
- What methods can help prevent powdery mildew from spreading?
- How can you manage powdery mildew without harming plants or the environment?
- What is the life cycle of powdery mildew and how does it spread?
- Can you save parts of plants infected with powdery mildew?
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.
Powdery mildew is a common problem that affects cannabis plants, caused by various types of fungi. These fungi manifest as white or gray powdery-like growths on the foliage of your plants. As a cannabis grower, it’s crucial for you to identify and understand the signs of powdery mildew, as well as the steps you can take to prevent or treat this issue during your plant’s flowering stage.
Your plants may show symptoms such as discoloration, leaf deformities, and overall deterioration of health due to the presence of powdery mildew. It’s essential to be aware of the potential risks associated with this fungal infection and learn the most effective methods to eliminate it from your plants. In doing so, you’ll be better prepared to maintain a healthy environment for your cannabis plants, both indoor and outdoor, while minimizing the chances of losing your valuable crop to this persistent fungus.
What is Powdery Mildew?
Powdery mildew is a common fungal disease that affects a wide variety of plant species. It appears on the surface of leaves, stems, and flowers as a powdery, white or gray growth. This fungus reproduces through spores, which can easily be spread by the wind, air ventilation systems, pets, or humans. Once the environmental conditions become ideal, these spores can germinate and lead to a full-blown fungal infection.
Although not all plants suffer severely from powdery mildew, it can still have significant impacts on their health and productivity. When left untreated, the disease can slow down photosynthesis and potentially ruin a harvest. It is essential to regularly check your plants for any signs of this fungal growth, as catching the problem early on will help you combat it more effectively.
To safeguard your plants from powdery mildew, consider using a product such as Bergman’s Plant Protector. This plant protection system has several benefits:
- Shields your plants from diseases and harmful pests
- Includes three 20 ml bottles, enough for up to 20 plants
- Compatible with soil, hydroponic, and other grow mediums
By taking preventive measures and staying vigilant, you can better protect your plants from the devastating effects of powdery mildew and ensure a healthy, productive growth.
Signs of Powdery Mildew on Cannabis
When it comes to identifying powdery mildew on cannabis, look for fuzzy, circular patches resembling flour on your plant’s leaves. Leaves may also appear spotted, mottled, and wilted. This infection rapidly spreads to nearby foliage and can cause extensive damage.
The stark white appearance of powdery mildew is easily recognizable against the green leaves. Timely and proper treatment is essential for removing it. However, dealing with powdery mildew spores can be challenging since they’re difficult to see and spread through the air.
To prevent mildew formation, ensure adequate ventilation, proper temperature, and humidity levels in your growing area. Avoid overcrowding, which can facilitate the spread of mildew between leaves. High humidity levels (above 55%) and poor air ventilation further increase the risk of powdery mildew.
Young plants are often the first target of powdery mildew, which can then spread across the entire plant, affecting stems, buds, and leaves. Infected buds will have a damp smell, and white powdery mold might be visible as well.
If left untreated, the fungus will cause the plant to turn yellow and eventually brown, ultimately leading to the plant’s death. To avoid losing your plants to powdery mildew, inspect them regularly and monitor for any unexpected changes.
In addition to cannabis, powdery mildew can affect various plants, such as roses, cucumbers, zinnias, pumpkins, trees, melons, beans, lilacs, vegetables, tomatoes, peppers, peas, phlox, and monarda.
Remember to maintain a diligent and preventive approach to cultivate healthy and high-quality marijuana plants.
How to Eliminate Powdery Mildew During Flowering
Preventing Powdery Mildew Infection
One of the best strategies for dealing with powdery mildew is to take measures to prevent it from occurring in the first place. When planting or transplanting your plants, ensure they have sufficient space between them. Close planting can increase the likelihood of powdery mildew developing.
Watering your plants at a time when they will receive at least five hours of light afterward, either natural or artificial, can help prevent powdery mildew. Indoor growers might also consider using UVC lights to protect plants from any lingering spores. Experienced growers may prune leaves that receive no direct light due to shading, reducing ideal spots for powdery mildew growth while conserving plant energy.
Addressing Powdery Mildew Spores
If powdery mildew does appear, various treatments can help eliminate it. Homemade remedies include mixing one-half teaspoon of baking soda with a quart of water and applying the solution to affected plants.
Alternatives for tackling powdery mildew include oil sprays like neem oil, sesame oil, or fish oil. A milk spray mixed in a 40% milk to 60% water ratio can also be effective due to the sun-reactive proteins in milk that form a natural antiseptic. Apply the milk spray every ten days when the plants are exposed to bright sunlight.
For infected plants, carefully remove affected leaves using a plastic bag to prevent spores from spreading. Seal the bag and dispose of it in a lidded container. Treat the remaining plant stems with a fungicide.
Other methods
Cinnamon oil, garlic oil, coriander oil, clove oil, jojoba oil, and cottonseed oil sprays can be used as alternative healing methods for your plants. Copper-based applications from any garden center may also be helpful. Another option is mixing one tablespoon of hydrogen peroxide with water, which destroys the fungus through oxidation. Limonene mixed with water provides fungicidal properties without killing the fungus entirely.
Sulfur burners can be employed to control and contain the fungus, but avoid the area during treatment to prevent respiratory inflammation. Afterward, clean all windows and walls to remove sulfur residue.
Powdery Mildew Plant Symptoms
White Powdery Mildew on Leaves
- Pale colors
- White patches on leaves
Symptoms on Leaves
- Affected upper leaves and newer growths
- Impacted lower leaves and older growths
- Visible white powdery patches on the leaves
- Spots
- Mottled, mosaic on leaves
- Wilting and drooping of leaves
Symptoms on the Entire Plant
- Mold growth on various parts of the plant
To remove powdery mildew from infected leaves, you can try gently wiping them with a damp paper towel, taking care not to disturb the leaves too much to prevent spreading spores. To prevent future mildew growth, consider incorporating at least two fans into your growing environment: one to direct air through the plant leaves and another to expel warm air from the growing area, replacing it with fresh air.
Remember, plants with strong genetics are less likely to become sick and more resistant to pests and diseases, so choose high-quality seeds from a reliable source to ensure your plants’ health.
FAQ about Powdery Mildew on Cannabis
- Health risks: Powdery mildew interferes with your cannabis plant’s photosynthesis process, which can ultimately compromise your harvest. It’s essential to address it as soon as you notice it.
- Elimination from buds: Unfortunately, you cannot remove powdery mildew from buds once it has invaded. The plant will likely turn yellow, then brown, and eventually die.
- Treatments: Some common treatments for powdery mildew include oil sprays like neem, garlic, and sesame oil. Other options are copper-based applications and products such as Mold Control and Bergman’s Plant Protector. Additionally, sulfur burners can be useful.
- DIY treatments: To create a homemade spray, mix 40% milk with 60% water, or dissolve one tablespoon of hydrogen peroxide in water.
To prevent powdery mildew, consider the following factors:
- Climate and temperature: Favorable conditions for powdery mildew include high humidity and low light. Maintain a dry climate and sufficient sunlight to prevent its development.
- Watering: Avoid overhead watering, which increases the likelihood of powdery mildew.
- Compost and nutrients: Keep your plants healthy by providing proper nutrients through compost and appropriate fertilization.
- Resistant varieties: Opt for resistant cultivars if you face recurring powdery mildew issues in your growing area.
- Plant debris: Regularly clean up plant debris, as it can host powdery mildew spores and spread the disease.
Remember, maintaining healthy plants and providing the right care during the growing season will help in preventing powdery mildew on cannabis.
Frequently Asked Questions
What can you do to effectively treat powdery mildew on plants?
- Remove affected leaves and dispose of them properly
- Apply a fungicide that targets powdery mildew
- Use biological control agents such as certain fungi or bacteria
- Increase air circulation around plants and avoid overcrowding
- Limit excess moisture by avoiding overhead watering
How can you recognize powdery mildew symptoms?
- White or grayish powdery spots appearing on leaves, stems, or flowers
- Distorted or stunted growth of leaves and shoots
- Yellowing of leaves, followed by browning and leaf drop
- Infected flower buds may fail to open or bloom properly
What methods can help prevent powdery mildew from spreading?
- Regular inspection and removal of affected plant parts
- Create a less favorable environment for powdery mildew by maintaining good air circulation and minimizing excess moisture
- Plant varieties that are resistant to powdery mildew, if available
- Apply preventative treatments like fungicides or biological control agents early in the growing season
How can you manage powdery mildew without harming plants or the environment?
- Use environmentally friendly substances such as horticultural oils or baking soda mixed with water
- Introduce beneficial insects or microorganisms that can help control powdery mildew
- Implement cultural practices like proper spacing, watering, and pruning to promote plant health and avoid creating conditions favorable for powdery mildew
What is the life cycle of powdery mildew and how does it spread?
- Powdery mildew begins as tiny spores that land on plant surfaces and germinate under favorable conditions
- The fungus grows on the surface of the plant, forming a visible powdery coating
- The fungus produces more spores, which can spread to other plants via wind, water, or by contact
- The cycle continues as the new spores germinate and infect more plants
Can you save parts of plants infected with powdery mildew?
- It is possible to salvage plants if the infection is caught early and treated promptly
- Remove affected leaves or other plant parts to prevent further spread
- Monitor the plant’s health and apply treatments as needed until the infection is under control
- Maintain good cultural practices to help the plant recover and prevent future infections
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.
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.
I recently purchased wedding cake and master kush they grew very well got 9 feet tall but white powder mildew caused me to throw away 7/ 9′ tall plants loaded with buds? I grow out side in western new York I can’t control hummidy what can I do? Can you treat the infected plants loaded with buds I sure don’t want to smoke it!
If you’re able to treat it effectively you can save your yield. For heavily affected plants use fungicides: use products labeled for use on cannabis and effective against powdery mildew. Organic options like potassium bicarbonate, or sulfur can be effective. Follow the manufacturer’s instructions carefully.
If it’s relatively mild you can wash the affected buds with a mixture of water and baking soda (1 tablespoon per gallon) to reduce powdery mildew colonies.
I’m real close to harvesting my Afghani auto and it might have powdery mildew. What can I do and will it be safe to smoke if it isn’t all gone? Other than the white powder on leaves it looks healthy
Hi Pat,
Remove all affected areas as thoroughly as you can. You can consider treating the plant with a baking soda or milk solution. You don’t want any of the PM on your buds though, trash any affected buds. And washing the buds with either a milk or baking soda solution is definitely not ideal. So cut your losses and salvage what you can if the buds are affected.
Do I need to rinse leaves off after spraying baking soda/water?
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
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?
I’m in day 50 of flower. I’m spraying milk/water to fight powdery mildew . Will that harm the THC in my buds?
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.
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?
Thank you for showing me tips in removing white powder mildew on plants.
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?
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.
Is there a certain type of dish soap you have to use?
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.
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.
Why r my leaves turning yellow?good site lots of info
How do you know after you spray if the mold is dead. Does it leave a residue?
Will spraying plants with water baking soda hurt buds?
Can you spray when bud are present.
Thanks for the all the info on growing
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 !!
Do u rinse off the apple cider vinegar once u have sprayed your plants
I can’t get Bible to download
Hi there,
If you can’t get it to download please don’t hesitate to get in contact with us at [email protected]!
Stacy
ILGM
Tried to download ur grow bible wouldn’t let me. Page been removed it said
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.
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?
Have boy and girl planted close together. I grow for Seed
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!!!
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
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
Love all the useful tips! Thanks for keeping it real!
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.
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
Can I Treat white powdery mildew with peroxide when in flowering stage?
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.
How often should you spray the leaves that have powdery mildew
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
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.
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: ilgmforum.com. See you there 🙂
Not wise to smoke pores..
Even if dried..
I wouldnt .
Can i spray the milk&water mixture on my buds??
4th week into flowering
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.
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
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!
Thats my issue aswell .im in my 4th week flowering..mildew isnt bad..few spotts
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
michael,
ACV?
I suggest following the directions when using any product.
How often do you spray, using apple finger and water?
In general indoors or in greenhouse we treat plants once every week or 2 to be proactive
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.
1doug,
Yes, UVC lights are known to a lot of growers, especialyl growers that are always adapting to newer ideas and products.
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 ?
After apple cider spray do the plants need to be washed and how long til they can be harvested.
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 !!
Thanks Jim 😀 I will have to check and see how safe this product is to use.
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.
Thanks everybody
[…] grown outdoors, however, it has the ability to stretch a bit more. Because it can be sensitive to powdery mildew, it is recommended to keep the humidity low when growing Green Crack. Ideally, when grown outdoors, […]
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.
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.
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
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
Hi ,where did you purchase this product?
[…] Quisqualis These are naturally occurring hyperparasites of powdery mildew. They form colonies on the infection, reducing growth and may eventually kill powdery mildew on […]
[…] 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 […]
[…] might have cracks that mold could travel through. Any damage caused by caterpillars, snails, worms, mildew, or other pests can also create a “tunnel” of sorts for gray mold to get inside your […]
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!
Thanks for sharing Newbie grower!
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.
How often can i spray my plants with the Vinegar water/
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.
Thanks for sharing Housewife Grower
What is ACV?
Apple Cider Vinegar
apple cider vinager
Awsome info,hope it will do the same on out door grow
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
how often do you treat with this method?
Hi VF,
We discuss several methods in this article, to which method exactly are you referring?
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!
[…] 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 […]
[…] Powdery mildew […]
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
Thanks for the tip Bill.
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.
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
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.
Thanks for sharing!!
Im using jakes all purpose spray hope it works all organic
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
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.
I just want to say…Thank you for this Info, and your help 🙂
iam trying applecider vinegar on my babys. white powdery mold starting on leaves. I really hope this works.
I just seen three leaves affected after humid rain and sprayed with apple cider
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.