White Mold on Phalaenopsis Leaves: Mealybug Identification and Systemic Treatment

Question:

I have white mold on the side and underside of new Phalaenopsis leaves. What to do?

Answer:

Hello Michele,

If it's truly mold, mix a few drops mild dish soap in warm water, wipe affected leaves with soft cloth—mold should come off. But if it's what I suspect, you'll find tiny insect bodies on the cloth: mealybugs! They'll slowly kill your orchid.

For mealybugs: get systemic orchid insecticide from garden center. Mix per directions, water with it. Requires 3 applications over 3 weeks to catch hatchlings. Repeat in fall for newcomers.

Jim Kawasaki
San Jose, CA