I have a white powder substance on my Japanese Maganolia leaves?

Question

Every year my Japanese Maganolia tree starts off with beautiful green leaves........and then becomes covered with a white to gray powdery substance, I have tried commerical sprays but it does not help.
Anyone know of a good natural solution to keep the leaves looking green and pretty ?

Answer 1

Sounds like powdery mildew. It's a very common thing regardless of where you live. Any commercial anti-fungal spray will take care of it. I use Immunox with good result for both powdery mildew and black spot on the roses.

Answer 2

this sounds like powdery mildew.

powdery mildews are specific to each host plant, they generally won't spread to other varieties.

my personal theory is that powdery mildews are a symbiotic relationship, preventing insects from eating the leaves.

a soap and water solution can be used to improve the appearance of the leaves, though it needs to be used to wash the leaves, not merely sprayed on.

Answer 3

That is a fungus. The best thing that I have found for fungi is systemic fungicide; this is the type of pesticide that is actually taken up into the plant. It makes the plant "poisonous" to the pest; however, it needs to be started BEFORE the problem occurs each year - preferably as soon as it starts to get warm.

Check with a nursery to find the right kind of systemic fungicide for your conditions. Also remember never to use systemic pesticides with plants that you will eat, as they do become part of the plant, and you would ingest them along with the plant parts that you consume.