My Pot Leaves Are Covered With White Dust

Dear Dan, My (outdoor) plants have flowered for a month now. The sun leaves have turning yellow. Lots of white dust on the buds. How much longer do I have before they are ready to harvest? – Julius S.

Dear Julius,
You have two alarming issues going on with your plants. First, the sun leaves (or fan leaves) shouldn’t be turning yellow after only a month of flowering. They should only start to show fall colors in the last two to three weeks of flowering so I’m thinking you may have a nitrogen deficiency or an issue with an imbalanced pH.

The second, and more disturbing, situation is the one you describe as “white dust” on the buds. If you’re talking about glandular trichomes (often referred to as crystals or resin glands) then you’re in the clear but if it truly looks like dust, you just might have an issue with powdery mildew. Take a closer look with a loupe or microscope to properly diagnose the problem. If you see tiny mushroom-like glands with a stalk and a bulbous head, it’s just the normally occurring trichomes that contain the desirable cannabinoids. If you see what still looks like dust particles, your problem is PM.

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