Home gardening -- bushes with infestation

Asked May 25, 2018, 5:37 PM EDT

Please take a look at attached pix of bushes on side of our house. They don't look so good. What do you suggest? Thanks!

Montgomery County Maryland shrubs euonymus cottony camellia scale soft scale scale scale on euonymus euonymus with scale euonymus with black leaves

3 Responses

This euonymus is infested by an insect known as scale. It's a soft scale, a type which excretes a liquid known as honeydew. A black fungus then grows on the honeydew--the black fungus is called sooty mold. That's why the leaves are black.

We can't see which species of scale it is from the photos. Here is information about soft scale and how to manage it: http://extension.umd.edu/hgic/plants/soft-scales-trees-and-shrubs

Both cottony camellia and wax scale will get on euonymus. If you can send us clear, close up photos of the leaf undersides and stems, we may be able to narrow down what kind of scale it is for a more precise treatment.

ECN

Thanks for your quick response. Here are a few pictures that show the scales more closely. Please take a look and let me know what you think about treatment. We prefer to use something natural rather than chemicals, if possible. THANKS!!

This looks like cottony camellia scale. Prune out and dispose of the more severely infested stems. Spray with horticulture oil (it is considered to be an organic treatment). There is one generation a year, but each female can produce over 1000 eggs and populations can build up quickly. Eggs hatch and crawlers are active in late May and early June. This is actually the best time to spray as spraying during the crawler stage is more effective. When the insect is protected by its scale cover they are shielded from the spray. Spray again during the dormant season. Usually, the label directions of horticulture oil will give two dilution rates,
one for the growing season and the other for when plants are dormant. So read and follow the label directions.
Please see the following information from our website.
http://extension.umd.edu/hgic/cottony-camellia-scale-shrubs

dr