Q.why does my broccoli have a white chalky substance on it?
We live in MN. Why does my broccoli have a white chalky substance on it? We have an organic garden.
Certified GKH Gardening Expert
If they are chalky, it could be the type of water your are using. It may be mineral deposits building up on the leaves. Watering with a distilled water will stop this.
If they are fuzzy, this is mealybug and this article will help you treat it, as will neem oil, which is safe and effective: https://www.gardeningknowhow.com/plant-problems/pests/mealybugs-white-residue-on-plants-leaves.htm
If it's more powdery in nature, then powdery mildew may be the problem. Neem oil will help with this too. Here is more info: https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm