is there any way to rid it? The weather is rough during the summer in these parts. it’s going to be hot and humid from here on out. Do I remove the infected leaves?
The mildew spores are 'blowin' in the wind' so singing along to the song might make it seem like less of a problem. There is no way to get rid of it, but there are ways to slow down how fast it spreads on the plant.
Mildew is one of the major issues with outdoor growing. There are something like 7 varieties of powdery mildew and each variety will infect certain plants and not others. It can become worse on some of the other flowers and vegetables in our outdoor gardens but they are not the source of the same variety of mildew as on our Cannabis plants from what I can tell.
Cutting the leaves off will not help. If you can see the infected areas then it means that there is good chance the rest of the leaves have already been infected and it is just a matter of time before the white Powdery Mildew starts showing. Keep cutting off the leaves and in about a month there will be none left.
There are a bunch of recipes for home-made sprays to help get rid of the mildew and to help prevent it from coming back but I did not have success with them. There are some commercial sprays on the market so take a look at your local gardening or hydro shop to see which will be the easiest for you to use. These work by putting a mild acid solution on the leaves and this prevents the spores from starting to grow. If the mildew is already present then the mild acid will start to kill it.
There is a recipe here on this message board for a home-made spray that will help to keep the mildew under control but I have lost the references to it. I do remember the basic recipe for making one pint at a time.
5 gram of Citric Acid (Citric acid is available at large supermarkets in the canning/food preservation area. Also available at some neighborhood hardware stores-but not big box stores.)
1 pint (16 fluid ounces) of water
Couple drops of mild soap (Mild dish detergent will work but just use a couple of drops)
Mix and spray the top and underside of the leaves.
The mildew will die within a day or two and after awhile there will be a "scar" left on the surface of the leaf which shows the damage done. This 'scar' will not go away but the rest of the leaf usually looks like it will be healthy.
Some growers will inspect their plants and use a damp paper towel or damp cloth to wipe any mildew off of the leaves before spraying.
The mildew needs calm and warm humid days to grow. It needs dry days with low humidity and a nice breeze to spread from one plant to another. It will not spread in the rain or from wet leaves....but the rain or water on the leaves helps it grow if the spores are already on the plant.
I start spraying as preventive when the plants go outside. A regular spray even if no mildew is showing helps hold off the problem.
