How to fight wwhite powdery mildew

[Joes grows ct]

Sorry no pictures. Anyways my outdoor blackberry larger fan leaves have a powder mildew color grayish kinda were the dew sits on the larger leaves she doesn't get much son I pulled all the large fan leaves I can't tell if anything is on the buds cause there's extremely frosty like crazy . Is there a mixture of hydrogen peroxide I can use also is it possible the thc or so.ething in the tricromes can fight off the powdery mildew I really want this crop please lmk .