Peony with powdery look

Asked August 16, 2015, 10:18 PM EDT

We planted a hybrid peony last fall and it bloomed as planned earlier this summer. We have noticed over the past month that it has wilted and seems to have a powdered substance that is moving toward the root, but the root is maintaining a hearty green color. Is it mold? Have we not watered it properly? Is this the look for a peony after it has blossomed? It is Paeonia "Bowl of Beauty' Garden peony - name from tag. If it needs to be removed, are we safe to move something else to that spot? it has lavender on the other side, which is very hearty, a lilac bush and is partly shaded.

District of Columbia County District of Columbia

1 Response

This is powdery mildew. They may also be wilting from lack of water.

This is powdery mildew, a fungal disease. In future years, you could try spraying a fungicide with powdery mildew on the label--but you must apply it before the disease gets established. Fungicides are preventatives--they are not curatives. It's possible that it will not get this disease every year.

At the end of this growing season, cut the plants to the ground and dispose of the diseased material off-site. This garden sanitation reduces the amount of infectious material around next spring.

Do not cut down the plants now, even though they are covered with mildew. They are still able to carry on photosynthesis (though at a reduced level) and feed their roots.

These plants also look wilted. We are in the midst of a multi-week drought. Keep in mind that newly planted tree, shrubs, or perennials, need supplemental watering for 2 years at least while their roots get established. Plants like about 1" of water a week, so water when rainfall is deficient.