Is this powdery mildew or just frosty weed?

Capt. Trips

Well-Known Member
The title pretty much says it all. I think these are probably about two weeks or so from being done, but I'm not sure if this white stuff is PM or just crystal. I've had PM problems throughout the grow, but it's mostly been on the big fan leaves. This is only showing up on the little sugar leaves. Under a microscope it looks like ice crystals rather than trichomes. I have some GreenCure but I don't want to spray if I don't have to.

So what do you think - is this powdery mildew, and should I spray with the GreenCure? Or is it just frosty weed? I have a bad feeling it's PM, but I want more opinions.

Thanks in advance.

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Alienwidow

Well-Known Member
Holy smokes trips, your supposed to add water to the nutrients before you pour it into the plant. Slow down on the food next run. And spray baking soda mixed with water. One teaspoon to a sprayer bottle of water. It will lower the ph on the leaf making the pm unable to grow. I would be doing right now to all of your plants right now. Except on the flowers, just leaves. Also if you have a fan blowing on the effected plant (s) then the fan will spread the pm to the other plants.take off the leaves with large spots and the buds with it on can be picked through and turned into bho once the pm spots are removed from the flowers.
 

Capt. Trips

Well-Known Member
Holy smokes trips, your supposed to add water to the nutrients before you pour it into the plant. Slow down on the food next run. And spray baking soda mixed with water. One teaspoon to a sprayer bottle of water. It will lower the ph on the leaf making the pm unable to grow. I would be doing right now to all of your plants right now. Except on the flowers, just leaves. Also if you have a fan blowing on the effected plant (s) then the fan will spread the pm to the other plants.take off the leaves with large spots and the buds with it on can be picked through and turned into bho once the pm spots are removed from the flowers.
I actually haven't been feeding heavily at all. I've fed well below the suggested amount, and the temperature stays around 23c with the lights on. They've been flowering almost eight and a half weeks, so whatever the issue is, I'm hoping they can ride it out just a little longer.
 

ttystikk

Well-Known Member
Instead of sodium bicarbonate, use potassium bicarbonate- it does the same thing, only now you're adding a nutrient directly to the leaf.

Silica works well, but needs a surfactant/wetting agent, explained below.

Use a wetting agent- that stuff he showed off in the video had corn oil, other things work as well- I happen to like Safer brand Insecticidal soap, it's just as safe and it's an excellent control for a broad range of pests- and even if you don't have any bugs, consider it a literal ounce of prevention.

In the last week of bloom, a ten percent solution of milk- yes, moo juice- is effective and inexpensive. Using it will turn bud hairs red, hence only using it late. It does not have great persistence, so using it early won't help you.

Eagle-20 is a very powerful fungicide. I don't use it but if you do, make certain you never spray within 70 days of harvest. Overuse can lead to resistance, a problem the other methods don't have.

PM is not caused by high humidity; it's caused by highly variable RH, which is why it's wise to keep your RH within a fairly narrow range.

There ya have it: What the pros do- and there's plenty of us in Colorado.

Good luck and happy gardening!
 

Capt. Trips

Well-Known Member
Instead of sodium bicarbonate, use potassium bicarbonate- it does the same thing, only now you're adding a nutrient directly to the leaf.

Silica works well, but needs a surfactant/wetting agent, explained below.

Use a wetting agent- that stuff he showed off in the video had corn oil, other things work as well- I happen to like Safer brand Insecticidal soap, it's just as safe and it's an excellent control for a broad range of pests- and even if you don't have any bugs, consider it a literal ounce of prevention.

In the last week of bloom, a ten percent solution of milk- yes, moo juice- is effective and inexpensive. Using it will turn bud hairs red, hence only using it late. It does not have great persistence, so using it early won't help you.

Eagle-20 is a very powerful fungicide. I don't use it but if you do, make certain you never spray within 70 days of harvest. Overuse can lead to resistance, a problem the other methods don't have.

PM is not caused by high humidity; it's caused by highly variable RH, which is why it's wise to keep your RH within a fairly narrow range.

There ya have it: What the pros do- and there's plenty of us in Colorado.

Good luck and happy gardening!
GreenCure is potassium bicarbonate. I gave them a good spray last night, so I'm hoping that will keep it under control until they're finished. I've used milk a few times and it's kept it away for a week or two at a time, but I wanted to try the GreenCure this time. Now I'm looking forward to this run being done so I can start a new one with much more knowledge than I had for this one.
 

ttystikk

Well-Known Member
GreenCure is potassium bicarbonate. I gave them a good spray last night, so I'm hoping that will keep it under control until they're finished. I've used milk a few times and it's kept it away for a week or two at a time, but I wanted to try the GreenCure this time. Now I'm looking forward to this run being done so I can start a new one with much more knowledge than I had for this one.
Quit hoping you can not spray every week- they are very good for the plants and you can add foliar nutrients to the mix as well, like kelp.

Get in the habit of spraying weekly- you and your plants will appreciate it.
 

Capt. Trips

Well-Known Member
Quit hoping you can not spray every week- they are very good for the plants and you can add foliar nutrients to the mix as well, like kelp.

Get in the habit of spraying weekly- you and your plants will appreciate it.
I'm definitely going to listen to your advice and do routine sprays on my next run. Especially now that I've seen first hand how much of a pain in the ass powdery mildew can be. I feel like my next attempt will be much more successful than this one, but I'm still happy with my first try at indoor, even though it should have been much better. Thanks for the advice. It's very much appreciated.
 

toomp

Well-Known Member
I'm definitely going to listen to your advice and do routine sprays on my next run. Especially now that I've seen first hand how much of a pain in the ass powdery mildew can be. I feel like my next attempt will be much more successful than this one, but I'm still happy with my first try at indoor, even though it should have been much better. Thanks for the advice. It's very much appreciated.
Fox farm foliar remove powdery mildew gives boost to buds not listed but main ingredient may be peroxide. Check it out works grest
 

Deusracing

Well-Known Member
Instead of sodium bicarbonate, use potassium bicarbonate- it does the same thing, only now you're adding a nutrient directly to the leaf.

Silica works well, but needs a surfactant/wetting agent, explained below.

Use a wetting agent- that stuff he showed off in the video had corn oil, other things work as well- I happen to like Safer brand Insecticidal soap, it's just as safe and it's an excellent control for a broad range of pests- and even if you don't have any bugs, consider it a literal ounce of prevention.

In the last week of bloom, a ten percent solution of milk- yes, moo juice- is effective and inexpensive. Using it will turn bud hairs red, hence only using it late. It does not have great persistence, so using it early won't help you.

Eagle-20 is a very powerful fungicide. I don't use it but if you do, make certain you never spray within 70 days of harvest. Overuse can lead to resistance, a problem the other methods don't have.

PM is not caused by high humidity; it's caused by highly variable RH, which is why it's wise to keep your RH within a fairly narrow range.

There ya have it: What the pros do- and there's plenty of us in Colorado.

Good luck and happy gardening!
We killed ours with 3% hydrogen peroxide after harvest. Dunk soak and rinse till u see no more float to the top shake off and hang
 
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