Powdery Mildew

If you’ve ever noticed a white or gray, powdery coating on leaves, stem or buds, you’ve likely seen powdery mildew. It can make plants look like they’ve been dusted with flour or baby powder. The good news is that while it spreads quickly, it usually doesn’t cause serious harm to trees. Still, it can make ornamentals look rough and sometimes affect the taste or growth of fruits and vegetables.

Powdery mildew shows up most often on young leaves and shoots. You might see curling, twisting or wilting of leaves, or early leaf drop, and in some plants the leaves even turn yellow, red, or purple. It tends to thrive in shady, humid spots where air doesn’t move much, but it struggles when leaves stay wet from rain or irrigation. Spores spread by wind and insects and can hang around over winter in buds or old plant debris, ready to come back in the spring.

The key to managing powdery mildew is catching it early and staying consistent. A little light pruning in winter helps open up the canopy for better air flow and sunlight. Avoid over-fertilizing, since that can encourage new growth that’s easy for the mildew to attack. Choosing resistant plant varieties and cleaning up fallen leaves can also make a big difference.

If you’ve dealt with powdery mildew before, you might consider preventative sprays in spring. Options include potassium bicarbonate, neem oil or sulfur for plans that can handle it. Even simples home remedies like baking soda and water can help if applied regularly when the first spots appear.

Powdery mildew may spread fast, but with the right care and treatment, it can be controlled – and in many cases eliminated – so your trees and ornamentals stay healthy and looking their best.