White Powder on Leaves & Stem

[gmase22]

I found this white powdery substance on my leaves and stems on a few plants in my garden. I remember I had a similar problem when I used to live out in the woods. I'm assuming I carried it to the new house with my fan ( it could use a good cleaning). Any advice as to exactly what this is and how I should treat it would be great. I remember before using a water and baking soda spray but I don't remember what happened. Thanks in advance for your help.

 

[doughboy79]

hey bro, that's that white powdery mold, it sucks, its kinda like herpes, once they get it its there for life but it can be treated,the thing i did was neem oil them before dark, this will kinda break up the mold and make it liquid, then i rubbed the leaves gently and kind of rubbed off the now moldy neem oil. if you have other plants in the garden the best bet is to pull the infected and get rid of them before it spreads.spoken from experience you can still harvest them with the mold if you neem thoroughly a few weeks before harvest but some people complain about taste.....my practices might make some older more experienced grow gurus roll their eyes but i'm still learning too so if anyone has anything to add or correct please do

 

[Paladin]

I've read that misting with a hydrogen peroxide solution would help ..... but I don't recall what percentage of peroxide to use.....Try finding older threads on powdery mildew in the forums ....there may be answers there for you.

 

[BubbaKush]

yeah it works the hydrogen peroxide...but they have something to treat it specifically. check your hydro store... mine had it and treated it stays gone.

 

[gmase22]

Its not affecting the plants to much and has spread very little. I just sprayed them with a baking soda water mixture I read about it. Supposed to change pH of leaves to stop mildew growth.Thanks for the advice and Ill keep you updated. And will try to upload a better pic cus those didn't show much.

 

[Kujoe]

Its powdery mold. You can use neem oil or zero tolerance to treat it but don't. I get this all the time from clones and humidity problems. Listen to me take a quarter teaspoon of baking soda with one quart of water and spray down the plant. Make sure you don't get none in the soil or planting meduim because that will change the PH. Let it set for two days and then rinse them off with plain water, thats it. Its works and its safe.

Kujoe

 

[gmase22]

thanks for the advice kujoe. I used a baking soda mix and then sprayed it off after a lil over a day. It seems that the powdery mold is gone for the most part. It did cause the pistils on forming buds to slightly wilt from baking soda but other than that it seemed to work great.

 

[flyfishinrock]

that issue will progressively get worse if you dont spray it all the time, ie dailey or every other day. It WILL spread as its an airborn pathogen, that releases spores. To treat regularly try 2 1/2 tsps per quart of water. The reason I suggest h202 instead of baking soda is the huge mess and the dead pistols, with peroxide you dont get the white crap all over and dont have to wash it off. The peroxide changes the ph of the leaves to 7 and the spores cant survive, the disease is within the plant itself though and cannot be irradicated. The humidity needs to be around 40 or 50 to help with the problem and fresh air flow is a must.

 

[gmase22]

Very good to know. Thanks for the info. The plants seem to be doing great and no signs of any powder any more. I will possibly treat again if I see symptoms come back. I will give the H2O2 a shot next time instead of the baking soda because it is pretty messy, and not the best for budding plants. Thanks for all the help guys the plants definitely appreciate it.

 

[Mystic]

Increasing circulation also helps to minimize the spread and growth of powdery mildew. I also recommend vaporizing sulfur as an effective remedy. GOod Luck

 

[doughboy79]

woah, vaporising sulfer? how would one go about that?

 

[gmase22]

Thanks Mystic for the advice would I thought that also. I keep my exhaust fan running at night and a fan directly on the plants in my mother plants at night. How much airflow do you think they need at night?

 

[flyfishinrock]

Circulation is important at night but I would worry more about the humidity settling due to cooler temps at lights out, as warm air holds more moisture it can be sucked out easier by the exhaust. Try to cool it down before the light goes off if you can.

 

[Mystic]

You can go to almost any hydroponic business and ask for a vaporizer, they run around 150.00 or so. They should also have sulfur as well.
The sulfur changes the PH of the leaves creating an uninhabitable environment for mildew to grow on.
As far as increasing he circulation, you could create more space between your plants by just moving them around, I bend the branches to open them up and create more space, myself. More fans are good too. There are many ways to increase circulation for your plants. Good Luck

 

[Mystic]

Also, keep in mind that once the plant show signs of mildew they've already had it for a week. YOu might want to increase K potassuim and or add some silica (if you have not already), also using a beneficial bacteria would be advisable. All of these will help the plant to be more resistant to disease and pests. Watch for pest problems now as well, usually they will attack a weakened plant first.

 

[gmase22]

Thanks mystic thats some great advice. Very good to know.

 

[gmase22]

I have found that the baking soda mixture works much better keeping the mold away for a few days. But it damages pistils so I have only been using it on vegging plants. The H202 still works but needs to be used much more often to keep it in check. I also went to my local hydro store and they had a spray for this. It was nearly $20 and the main ingredient was baking soda so I just passed. Well just thought I would tell everyone my results. And again thanks for all the helpful information.