Cannabis growers are often faced with a problem called powdery mildew. This fungus attacks cannabis crops and makes it difficult to cultivate.
Powdery mildew spores are spread through the air and cause plant disease. This impacts cannabis production and even respiratory infections in humans if inhaled.
We will provide tips on how to prevent and remove powdery mildew colonies. So they don’t take over your cannabis garden.
What is Powdery Mildew on Cannabis?
Powdery mildew is a fungal disease and is a common, chronic problem on many kinds of plants.
The powdery mildew spores can be spread by wind, animals and by people. It can also be spread by infected plants.
The fungus that causes powdery mildew on cannabis is called Podosphaera-Lecanii.
There are a whole host of fungi that can cause Powdery Mildew.
Some of the more common ones are:
Erysiphe cichoracearum, Sphaerotheca fuliginea, Podosphaera xanthii and Podosphaera leucotricha.
Powdery mildew fungi has been around for thousands of years.
With the increase in cannabis production it is now becoming a common issue.
What Does Powdery Mildew on Cannabis Look Like?
Powdery mildew on cannabis is a fungus that has mold spores.
It appears as a white to off-white powdery layer of growth on the leaves and branches.
It is most often found on both the top and underside of the fan leaves and will appear as a white coating on the leaves.
Powdery mildew on weed looks a lot like dandruff.
The white fungal growth appears on the leaves as a fine coating, and can be seen with the naked eye.
What are the visible symptoms of White Powdery Mildew
Here are some of the signs of powdery mildew spores:
- White Spots
- Appears in clumps of white
- Looks like white flour on leaves
- Can be yellow or gray powder
- Slow plant growth
How Do Cannabis plants get powdery mildew?
Powdery mildew is caused in various ways and is easily spread.
The powdery mildew fungus grows best in moist conditions and higher humidity weather.
Temperatures between 70-80 degrees Fahrenheit are ideal for powdery mildew production.
Along with a high relative humidity at night and a low relative humidity during day.
Powdery mildew also prefers places that are lacking in air circulation.
That have a high humidity and aren’t exposed to much sunlight.
For many growers powdery mildew is common with greenhouse growers and outdoor grows.
Growing indoors is also an issue. The spores usually comes from outside factors such as:
- clones
- people
- pets
- or indoor house plants.
What causes White Powdery Mildew on cannabis plants?
Before we can look into preventing powdery mildew, let’s look a little deeper at the cause of the problem.
Clones and young cannabis plants can have powdery mildew hidden.
When growers spray the cuttings before selling.
You will not notice until two weeks later when the spray wears off!
High Humidity can play a huge factor in developing powdery mildew.
Anything over 60 percent humidity can significantly increase your chances of getting mildew.
OverCrowded Plants when plants are confined in tight spaces.
Like (sea of green) they cannot breathe and increase the humidity level in the grow room.
Air Flow with the lack of fans in the grow room or grow tent. With no air there is a chance of high humidity.
Rain and Dew issues when growing outdoors.
Water can linger on your infected plants leaves or buds when flowering.
Watering plants at night or lights out can also be a problem.
By not letting enough of the water evaporate with standing water.
Thus causing high humidity especially when using a grow tent growing in soil.
Not defoliating your plants. Allowing the buildup of excessive foliage in the undergrowth area of the plant.
Fans can be an issue if there is mildew detected. Because the spores and can be blown around by the oscillating fans in the grow room.
Best to turn these off until the outbreak is under control if you can.
How to Treat Powdery Mildew
There are many ways to get rid of powdery mildew on weed plants.
Some ways are the use of natural or home products. Or fungicides and foliage sprays to UV lights and special air filters.
The first steps to take are to remove the affected leaves on the infected plant that has the fungus.
You may also want to isolate and remove the whole infected plant. To make sure it will not affect the rest of the marijuana plants growing.
This is an extreme measure but one to consider.
Picture courtesy of Outer Elements Photography (Instagram)
How to Eliminate White Powdery Mildew
Trying to completely eliminate powdery mildew is very hard. Once it reaches inside the cannabis plant it becomes systemic.
The powdery mildew spores are nearly impossible to remove.
It is best to catch it in the early stages, and use some of the methods such as fungicides or other means to kill the fungus.
Or use preventative maintenance
Here are some ways to remove mildew on weed from your cannabis crop.
Natural Remedies
These solutions can be found around the house and are safe for leaves and branches.
Baking soda: one teaspoon per gallon of water
Spray solution on your leaves and buds. Check the next day, then spray twice on second day,wait one day if still around repeat
Apple Cider Vinegar: 2-3 teaspoons per gallon of water
Spray solution on your infected leaves. Check the next day, then spray twice on second day,wait one day if still around repeat
Milk mix 1 part milk to 3 – 5 parts water
Spray solution on your leaves and buds. Check the next day, then spray twice on second day,wait one day if still around repeat
I have not tried the milk natural remedy. But I have heard from other growers this method works well in the first stages.
One grower has reported he tried a milk solution and was successful.
Mix 400 ml milk to 600 ml water.
Leave the solution in a container in the Sun for about an hour. Then spray your plants
(Check out the comments for the science behind it.)
Hydrogen Peroxide for mildew: Use 1 tablespoon per gallon
Spray solution on your leaves and buds. Check the next day, then spray twice on the second day,wait one day if still around, repeat.
If you have moldy bud use hydrogen peroxide water bath to wash it off.
Potassium bicarbonate which is like baking soda but is much stronger. It will kill the powdery mildew spores very quickly.
Once the outbreak is beyond manageable with natural remedies. Then it means you must immediately move on to tested organic, safe foliar sprays to save your garden.
Natural Organic Products
Neem Oil a natural and organic oil that comes from a neem tree in India.
It’s great for removing powdery mildew.
Neem oil also has additional benefits of being an insecticide. You can also use it to kill insects in your cannabis crop.
Four teaspoons per gallon of water.
Green Cure Fungicide is for organic production and is made up of a Potassium bicarbonate that stops and prevents powdery mildew.
It’s also beneficial for all other fungus infection on your plants.
Green Cure has been tested in over 200 universities and is registered with the EPA
Safergro Mildew Cure is natural fungicide that is safe for organic food production and long lasting to control and prevent powdery mildew.
Banish the name says it all. This will literally banish any powdery mildew on your plants.
What’s really cool about his stuff is it works at the root of the fungicide.
Banish also creates a layer over the infected leaf . To prevent mildew colonies from germinating on contact with other leaves or plants.
This fungicide goes through a micronization process meaning it’s oils are shrunk down to 1 micron.
So Banish can really get at the mildew in its simplest form. You can use this funcide for treatment or even prevention.
Safe for all fruits and vegetables and also cannabis. Banish is made of all natural material it will also bio degrade from your plants and leaves over time as well.
Note : Banish is only available in the United States currently !
Check out the short video on it,
UV Light
UV Clean Light is a new technology to treat plants with UV light. The lights can be used as a preventative measure.
They are also used in treatment for powdery mildew and botrytis from plants.
You can also clean your grow room walls with this light.
The downside is they are really expensive , especially for the home grower.
UV clean light can definitely be used in a commercial or licensed produced grow operation.
How to Kill Powdery Mildew on Cannabis During Flowering
It is very hard to remove powdery mildew when your plants are flowering.
If you catch it early enough you can apply some type of fungicide or natural sprays in the first couple weeks.
Such as Banish, hydrogen peroxide, green cleaner, apple cider vinegar.
You would want to apply this before any major trichome development starts.
Or you could remove all leaves infected and even the buds to save the rest of your cannabis crop.
If there is powdery mildew after the first couple of weeks , it’s very hard to remove.
You could also check out this post on how to bud wash it off after harvest.
How to Prevent Powdery Mildew on Cannabis
There are many ways to prevent getting a powdery mildew infection with your plants.
- Control the temperature and humidity when growing indoors.
- Growing outdoors makes sure the leaves on the plant are not wet for extended periods of time.
- Defoliate your plant from getting to bushy
- Spray with a product for protection
- Ensure proper air flow
- Space plants apart so they are not touching each other in the grow area
- Eliminate standing water
How Long Does It Take for a Plant to Recover from Powdery Mildew?
Depending on the outbreak of powdery mildew and when you notice it.
With proper treatment and elimination of fan leaves or plants. It can take anywhere from one or two weeks.
Final Thoughts
A good rule of thumb is to stop the powdery mildew before it happens.
The main thing is to make sure your cannabis garden has a favorable environment.
With proper temperatures and humidity levels. Air flow and spacing between plants.
That is the key to preventing powdery mildew on cannabis.
Have you had powdery mildew infestation on your marijuana plants?
Did you use any of these solutions?
Let me know in the comments.
Keep on growing.
Reference:
https://extension.psu.edu/powdery-mildew
https://plantpath.ifas.ufl.edu/u-scout/cucurbit/powdery-mildew.html
http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Conidia.html
Great post. Thanks for sharing this information with us. Can we use UV technology for treating powdery mildew?
i had powdery mildew a few yeaes ago and i used most of the cures you listed but the final most successful was SAFRE spray from the grow store… it has sulfer in it which prevented any spread, but it does leave a residue and cant be used in buds
Hi Rachel,
Thank you for reading the post.
To answer your question , Yes you can use the special UV light to treat the mildew , but they are rather expensive for the home grower. I have put some info in post on UV light . check it out.
Thanks so much for sharing your information. I didn’t know what to if I ever had the issue. I’ve been lucky so far.
Thanks Parker.
LED grow lights claim to have UV does this feature prevent the mildew issue
Hi E,
Unfortunately you can still get mildew when using LED grow lights even if they have UV. The amount UV light they produce would not be enough to prevent it.
Never had pm, but recently switched from 1000w hps’s to Kind LED X-750’s, and my 1st run, I waaay overdid the UV/IR even though it’s controlled with its own knob, and killed my fans early on, so there is such thing as too much, for sure
Having much better results this time, tried to go into detail, but comment section here is stingy with space
Everything I’ve read has helped of all I use baking soda 3-4 spoons full – couple drops dawn – 1/2 cup apple vinger in gal water
How quick does it work?
I’ve been using led lights for over a year. They work great but I still get pm. Used neems for a couple years and I still have it. I spray all the time. Used a sulfur burner last night. It’s still there. Going to use it again in a couple days.
I bought some clones from a reputable source and four days later powdery mildew showed up. I’m trying the SM-90 since I already had it. I caught it early on at least so I hope it does the trick. I wish I had seen this article first, however, as I should have removed the infected leaves before spraying it around… live and learn!
Hi Holly ,
It’s tricky when you get new clones sometimes because the PM is usually been quick treated and hidden only to appear days later again. I hope your clones make it.
hi ive been using organic apple cider vinegar in a one gallon spray bottle on my inside grow, although it seems to be helping with the spread of the mildew it seems like its a battle with the same areas lower on the plants. ive decided to try some green cure do i apply this stuff with the lights on?
Hi Simmie
Green Cure is best to use when lights are off, and let dry . So right before lights out you can apply it.
Hope you get rid of the powdery mildew
Parker.
I currently have a mildew problem on my plants. It’s not powdery like the photos I’ve seen but rather more fuzzy. I’ve noticed it on the tips of fan leaves, which I’ve been removing. Today I noticed more of it on the upper part of the stem, I’m currently in flowering and haven’t sprayed anything as I’ve been worried about ruining the trichomes.
In what I’ve read within this thread thus far; is to remove all fan leaves that are affected and then spray? Would it remove the mildew on the stock as well without affecting the flowers?
It may remove it from the stock, if you can spray without touching the buds. may be tricky . Not sure the stage of flower your at, you may be able to wash off at harvest.
Hi like to know can you get powdery mildew out of the tissue of the plant. So you don’t have to worry about it coming out of the plant and have to keep treating the plant is there a way
Hi Daniel,
I am not aware of a way to remove powdery mildew from the tissue itself, maybe with the further advancement of cannabis research it will be around the corner. Unless someone else knows anything let us know in the comments.
Yes, you can remove all pest and mildew, including diseases, using maristem propagation aka tissue culture done in a lab
Actually, I believe doing tissue culture on your cannabis cultivars will get rid of all the diseases of, on and inside of the plant.
Or so Ive heard in interviews with heavy hitters in the industry like Kevin Jodrey mention it.
I havent looked into it personally , dunno if it is practical for the home grower to do/get tissue culture samples done up?
Tho I suppose if you have that sweetheart of a strain and it gets pathogens and diseases over time, and you have the means to ( I have no idea what tissue culture would cost?) then yea go that route.
Hi all, just to add on the milk solution, I have had complete success in curing advanced powdery mildew with milk… the way to use it is as follows dilute 400ml milk to 600ml water allow solution to stand in an open container in the sun for about an hour than spray entire plant, the science behind this is that milk when exposed to direct sun and air builds up natural antifungal and antibacterial enzymes that kill the powdery mildew on contact.
Thanks for the info Daniel that’s really good to know. I will try the milk solution it if I ever get powdery mildew again.
Does the milk solution need to heat up in the sun or is the light the only thing that matters? I’m wondering because it’s like 40 degrees outside and the solution will be cold even though it’s in the sun. Thanks!
Sean
I would try and heat it up indoors close to a window
How can you tell if powdery mildew that you’ve treated (safers defender) is gone? Should all the white have disappeared from every infected leaf?
The white may not all disappear but no new growth should be happening
How warm does the milk have to get
I would say warmer than room temperature
How often do you spray with milk and for how long
Thank you, now all we need is sun.
I have been using a peroxide and water mix for a few years with good results on powdery mildew and gray mold as long as it is a mild case. For gray mold ( bud rot) removal of infected buds and a liberal covering of the surrounding area did not stop the rot but slowed the spread enough to make it to harvest with minimal yield loss. As for the powdery mildew it seems to stop it in its tracks.
That’s Awesome Chad, Thanks for the comment if I get it again I will for sure check this out.
So I have had good success at eradicating powdery mildew that was determined early in the situation. Not a bad case just the insipiant stages of the disease by spraying with a solution of water and apple cider vinegar. Approximately 2 teaspoons of the vinegar to every litre of water. This will work on other plants thayvhlget the mildew as well. You need to treat well once and then repeat twice afterwards on the following days in order to actually kill the hook of the miceliam subcutaneous in the lead tissues. Regular suffocants will not kill the hook of the spores.
Thanks for sharing Paul , I always have bottle of apple cider kicking around. Will try it out next time , ( hoping there is not a next time! )
Hi Paul, can this be done 4/5 weeks into flower?
Excellent article, thanks!
My plants look great but I just noticed PM on some of them. They are growing outdoors and are in early bloom phase. It has been very hot here, so I have been watering everyday using drip irrigation.
Considering all these factors, which remedy would be best? Should I cut back on the watering?
Also thinking about prevention, as my garden is large and there is no way I can spray everything else…fortunately I haven’t seen it on other plants and trees…yet.
Any suggestions?
Thanks!
Hi Norma,
I would isolate the plants with PM and treat with banish. Or remove them completely. If you have a lot of humidity try spreading them apart if they are close together.
Also are you getting run off on your plants? If so and watering every day is fine , if no run off wait about half a day more or a day longer to water.
It’s tricky growing outdoors sometimes, Especially when it’s really hot, and you cannot control the environment.
What time of day should plants be sprayed for mildew?
The best tie to spray is in the morning or when lights are on or before the light goes off.
I run an outdoor farm in Humboldt, CA and we have been battling PM every year for the past 5 years. It never gets too bad but it definitely is a problem and is nearly impossible to eradicate once it sets in. We start our plants from seed and we feed compost tea weekly while using drip irrigation for watering every day around 4am. I am doing everything in my power this year to stop the PM from setting in. My preventative measures are; Spraying neem every 7-10 days starting in July and plan on stopping at week 6 of flower (end of September) to avoid harvesting neem covered buds, removing bottom branches and leaves that seem to be much more susceptible to PM also to support good air flow, and once a month I use wettable sulphur to spray the straw that we use to mulch our beds and cover our drip lines. I usually see the first signs of PM sometime in September depending on the weather that year. Do you have any suggestions of methods that could be used on top of what I have implemented already? I feel like PM is all about stopping it before it becomes an issue but its tricky.
Your right it is all about stopping it before it becomes a major issue , especially when you are growing outdoors. You seem to do everything on point. I am not familiar with growing outdoors and dealing with the different types of weather. I have big respect for you. The only thing I here good things about is the green cure and banish. Maybe cut the neem earlier on in flower.
The problem is in the straw that you have been using, I heard a friend had the same recurring mildew problem some years ago while guerrilla farming when things were illegal, he eliminated the straw and that eliminated the mildew problem. The problem arises when the bales are baled under high humidity conditions, it gives rise to mould growth.
If my plant was affected by Powdery mildew, will it be safe to smoke?
If you had it in veg stage and kept it at bay and is not on your buds then yes. If your buds are infected then I would not consume it in any way.
On this webpage you claim powdery mildew is harmful if ingested. Where did you get this information and could you share it please? Does it produce mycotoxins? Has it been shown to cause lung infections?
Thanks
Hi Sam, Looks like the link I had from Harvard changed . I have now updated it. Thanks for pointing it out. It has been known to cause respiratory issues. Here is some more info. https://www.health.harvard.edu/newsletter_article/By_the_way_doctor_Do_mold_spores_cause_lung_cancer
Can you most hydroperoxide treatment on buds?
i would not recommend it on buds.
Can u use the milk solution on. The buds
I never have, I would not do it to far into flower. May need to wash buds before drying.
I found PM in my indoor site .they are on week 7 flowers stage.i couldn’t see the buds get infecting.i only see some leafs from the lower area .last few days I’m using the hydroperpxide.but I’m not sure is it really working .because everyday I still see some new sport .now I just bought the UV light to try it .hope can help the sistiation .and my friends told me when harvest that moment dip the whole plant in to the hydroperpxide with water .after hang it to dry.so what do you feel about this suggestion ? They said they did it before and never effect the buds and farvor .thank you .
I have never washed my buds before hanging. to get rid of PM. Not sure how your trichomes development on the buds will handle the hydrogen peroxide.
Yes you can sterilize your marijuana at harvest time using water and a little bit of h202. Here is a video from Bid Daddy Jorge Cervantes on washing off powder mildew. I did this once with a Skywalker OG and it worked wonders. However, I only had a little bit of powder mildew and kept it in check for 20 or so days. Cam home one day with my exhaust fan not working and a little PM. Fought and kept it in check for 20 days then I clipped the girls and washed them. You pretty much fill up a container with water and add a few tablespoons of H202. Chop down buds, rinse like Jorge, stick in front of fans to dry for a few hours, then hangdry for 5 days.
Thanks Jesse
I have some stubborn powder mold all over my plant. I have been spraying with Neem oil but it doesn’t seem to have stop the spread and I’m seeing some on the buds. Can i use h202 to wash at harvest the buds, or are is it too late at this point to rescue? Harvest dat is approximately 3 weeks from today.
POWDERY MILDEW.
I had to go away for a couple of weeks, left girls in care of an unreliable baby sitter, when I returned mildew was out of control, lost them all.
Small outdoor organic grow in 15-25 gal fabric pots. Want to rectify problem and restore soil. Any suggestions ?.
Considering
> adding Mycos
> planting fall herbs/flowers
> ????
Thanks.
I would spray with a preventive as well , just not in flower.
I have successfully washed my outdoor with a 4 five gallon buckets.
First 5G bucket ad about 60ml of h202 into a warm water mix. Gently agitate for one minute. This breaks down and releases dead leaf mass, kills any pests and sterile’s the pm
Second 5G bucket about 40ml of pure lemon juice into again warm water mix gently agitating once more. This lifts dirt and any unwanted crap like pm off of your plant.
3 and 4 are both pure water. Again gently agitated in a double rinse One 5G bucket at room temp and one cool but not cold!
I will always wash my outdoor after seeing what came out of it.
1st time dealing with PM…Hoping its not completely advanced yet…Going to try the apple cider water mixture…would it hurt to also add baking soda?
I would not add the baking soda
What if your bud is harvested and while drying u notice the pm even gray pm is there anything that can help at that point
I would definitely remove the ones with mold then air dry the reset for a bit , then put back in jars if using and see if more mold appears. If so . sorry out of luck.
Also invest in a pocket microscope to check out the buds to see if you see any mold spores.
To be on the safe side most would recommend , to just throw out and take the loss and start again.
I am a first time grower. Someone dumped 120 small clones off one me. 80 are still alive. First it was the aphids. Then the PM. I thought I had the aphids licked by handpicking and lady bugs. But they keep on coming.
For the PM, I was instructed to ONLY use H2O2. And aggressive pruning. The PM went away, but it keeps coming back with a vengeance! Its pretty advanced. What would be most effective?
H.Hayes , I would invest in some Banish , It last a while and works well. Especially if you want to save 80 clones!
Can any body tell me the best way to get rid of pm. Ive bought some Canadian xpress pmt. and when ive opend the cap. it looks and smells like water. The pm on my plants Must be in first stages there as thete is only a couple of little white spots on the tips of the leaves.
When is the best time to apply the baking soda mixture during 18/6? When lights go on or when the lights go off?
I would go with lights off
I got clones for the first time and all had PM. It wasn’t noticeable for at least a month, but they were all infested. I hit them with green cure a few times and thought they were fine. It came back at 4 weeks of flowering, I treated again with green cure which burned all my pistils. My plants rebounded but now at week 8 it’s returning. I’m spot spraying, but it keeps creeping in. Of three plants one seems to be fine, one is getting it leaves only and the third is on the leaves and touching done buds. I sprayed again (just affected areas). I naturally want to get through to harvest without scrapping anymore than I have to, but also want my tent vacated so I can scrub it. Any advice? Should I be using GC this late?
That really sucks you have had to deal with the powdery mildew your whole grow. Your right best to clean and scrub as soon as harvest is over. I am not sure about using green cleaner so late in the flower. It will effect you bud potency if you are spraying buds as well. Best to try and finish the one .
Hi there
are you saying just to be clear that i shoujd get rid of the buds on any plant that has poydery mildew that it is definetly harful to your health even if i sprayed it with apple cider vinegar 2 weeks before harvest
sorry this is painful
ron, it is up to you in the end. I would check the buds with a microscope that you sprayed apple cider on and see if the mildew is still present
Actually, I believe doing tissue culture on your cannabis cultivars will get rid of all the diseases of, on and inside of the plant.
Or so Ive heard in interviews with heavy hitters in the industry like Kevin Jodrey mention it.
I havent looked into it personally , dunno if it is practical for the home grower to do/get tissue culture samples done up?
Tho I suppose if you have that sweetheart of a strain and it gets pathogens and diseases over time, and you have the means to ( I have no idea what tissue culture would cost?) then yea go that route.
thank you, good article. but . for us the home growers there are difficulties we face:
1.drying in a tent or a growing chamber, occupy space for 2 weeks.
2. the smell is hard when drying
3. mold- after all the hard work, if the mold appears, you can throw your harvest to the garbage.
4.drying in the perfect pace . not to fast and not to slow.
all these problems are over since i started using wedryer – a drying machine.
filter odor, prevent mold, free up the growing chamber,dry in about 5 days, and the quality of the drying is the best i had in my life.
i started using it 2 cycles ago and the quality is great, and because I start growing the day I trim, I do 1 more cycle a year. its about 100 USD and i change filter every 3 months.
the best drying machine for the home grower .
I been having pm for about last 5 harvest in its comes in 5th week of flowering so can’t do really much I did everything used all still come back Iam looking so something to give the plan with water so far i thing it’s inside the plan
Same with mine. I’m gonna do a bud wash as it’s not to bad mainly on the leaves to be trimmed.
Hello. I have been using a uvb light with a 275 california light works in the tent. A oscilating fan low and can filter and fan circulating from top to bottom of tent with a snorkle. Vpd has been successful with 72 deg and 74 rh. Does a uvb bulb help at all preventing mold?
No cliff I do not believe it does.
What if you live in a humid climate what can you do to prevent
You can use a preventative such as banish during the time of high humidity it will also remove mildew if forming.
If your plants always have powdery mildew how would you treat them when flowering
Treat them carefully and when harvest you could wash you buds in water and h2o2 , I never tried this method not sure on success rate.
We are 7weeks into budding do you need to remove bad leaves before spraying can you spray buds?
Yes before spraying…
Where can I buy Banish in Canada?
I have contacted the owners and they said they do not sell in Canada currently.
Try Safer
I am currently dealing with PM on some cuttings I took from a friends outdoor grow. I just mixed a 1/4 Tsp of Baking Soda in a 32 ounce spray bottle and plan to pray twice daily for the next three days.
On plants that are well into vegetative growth 2-3 foot tall, I have always done sulfur burns. If my plants were infected I would do three burns each with a day in between. If the plants are NOT infected I do a single inoculation burn to treat the plants. Inoculation burns are goof for five generations of cloning, I inoculate every 3rd generation just to stay well ahead of the threat.
Be careful though with with your burner as you can burn the plants and make them sick or even kill them dead if the burner is set too close to the pot. New burners will need more space between the pot and burner, after several uses it is likely the pot will need to be adjusted slightly closer to the burner. Set it up outdoors on a calm windless day to test the burner, a mild smoke is plenty. One Tbsp of Sulfur Pellets is good for several burns, if burnt on a single burn it will make your plants very sick if not kill them.
Late stage of flower I would guess 2 more weeks outdoor harvest. Started noticing pm on leaves been removing when I see it Nothing I notice on buds if pm was close to bud on leaf I pulled the bud and leaves. Anything I can do till harvest
Just stay diligent and watch for moisture in the mornings. You could try a preventive on the leaves, but may be tricky when spraying. Good Luck
Another Win for the Milk.
I was wondering if there is any need to rinse with water after the day or two of treatment and perform a quick fan dry? Also with the vitamins and minerals in milk, although not meant for nutrition on plants, what’s the consensus on benefits to foliage and bud material?
my babies are ready and today i was gonna start trimming. noticed the wpm. i dont have much time. its ready to go. whats the best way quick
You could try the wash method, it may work
I found a few spots on my plants just going into flowering, I tried the baking soda method but was slightly confused what happened when I checked them the next day after spraying the previous night….there are more white spots but not the fuzzy type of fungus…Im assuming baking soda residue?
Was about to harvest today and noticed pm struck hard on my 4 plants. I have been growing outdoors and I check on them weekly. I tried removing most of the infected leaves and washed a few with wet paper towel, I then used the mix of a gallon of water with 1 tb spoon soda and dish soap and veggie oil.
Spray on one day and twice the next and inspect the third.
I have been bringing them in at night with a fan blowing on them since they are in pots.
What I’m worried about most is if I should smoke or make shatter from it.
I don’t have a hand microscope if I’m not sure I got it all should I bath them like stated above and then dry?
If the solution works well do I need to do anything to awash the plants before harvest since I sprayed them with that mix or would they be okay to dry with that.
Thx in advance
the water bath should remove most if not all of the spray, by what jorge is explaining
If I have white on some buds is this definite mildew or is it the crystals turning white. Also if you do a hydrogen peroxide soak will all the white dissapear or does it just kill the mildew
It may remove the residue as well I have not tried the metod yet as I have not gotten Powdery mildew for a long time. Best to try it on a small bud and find out .
Curious how the burner worked? I Purchased one last week. This PM is a Pain!! I can spray with peroxide and water, leaves that get wet are white the next day.
After several grows with a no-pest strip, I never had PM until I grew without one. I suspects that the no-pest strip kills the PM as well.
Im currently in week 5 of flowering and I’m getting WPM, I check my plants everyday and it just popped up today, i removed every leaf I could find with it on it but I’m worried that it’s not all gone, can I spray my buds with neem oil this far into budding??
Tough call on the neem, maybe try banish? might be easier on your buds. That sucks man to get it this far in. Hope it works out for you.
I had same problem, used milk solution 3 part water 1 part milk, saturated all leaves and buds and was shocked , the next day, it disappeared. Did a second treatment, and sprayed the other plants. Hope it’s not a fluke, but so far, so good.
Hey, so I’m an outdoor grower and couple weeks into flower and found wpm never really had this problem into bud but I’ve tried the milk solution and it has worked pretty good but only on the spots that have full sun so it’s still coming back. But I’m also worried about having that sour milk taste appear when I smoke the stuff so I’ve done some looking around and was wondering about just ph water to 8.5 then spray does this work? And is it affective in the sun or is it a dust or dawn type? Thanks
I am glad the milk method is working for you, On the spray with water it’s a great question and I am not sure on if it will work, you can try if you like, i would probably do it during day time when sun is out.
Use skim milk
Doesn’t get funky smell
I found pwm on my plants and used the neem method. I removed most of the infected leaves. Made a solution of three teaspoons to a gallon and sprayed them. I’m three plus weeks into flower. Thank you guys for all the wisdom. Second year grower.
3 spoon fills of what?
Hello,
I have a PM Problem and would be thankful for any ideas or help.
I’ve been using a mix of baking soda, Zertol, Doc. Banners soap to get rid of PM but it doesn’t seam to be helping.
So I went to Neem and soap but it doesn’t seam to be helping.
I am thinking of Banish due to the PM really starting to spread.
I am not working in a home grow and the methods I am using are not working.
We clean fans (in a different location) and also make sure all tools are disinfected, no rooms are being watered at night or before the lights turn out, we make sure we are not going into different rooms when we are in 1 main room. We also deleaf without fans on when we see the PM. I leave the fans off for a short time to not spread the spores but nothing seams to help. We also have the humidity pretty even, even with watering so I’m just confused as to how this is spreading.
I do try to spray every 2 weeks with the Zertol mix and when switching to Neem oil, I am waiting 3 weeks in-between to spray.
Any ideas or help would be great.
I would give Banish try see how it goes. You have done a lot to prevent it. PM is a tricky beast.
If you are getting clones from outside your operation could be bringing it in. Looks like you have tried a fair bit of treatments. I would give Banish a try , what have you got to lose. It has helped other growers out there.