Asters yellow - Ask Extension
I'm pretty sure I have asters yellow in one of my plots of native plantings. The Echinacea flowers are weird--flowers on top of flowers, and the new ...
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Asters yellow #880603
Asked August 07, 2024, 5:14 PM EDT
I'm pretty sure I have asters yellow in one of my plots of native plantings. The Echinacea flowers are weird--flowers on top of flowers, and the new england asters growing next ot them have yellowing and brown leaves, which I thought was drought-related, but now I'm wondering about AY I've attached several photos.
Can you confirm asters yellow on the Echinacea?
Are the New England asters likely infected, too?
If the plants do have asters yellow, I know I need to remove them. Do I need to remove the other plants in the bed--fennel, butterfly weed, golden rod, coreopsis, chives, rosemary. lavender, flowering dogwood, anise hyssop that don't seem to be affected?
I have other beds of native plants that don't seem to be affected, or at least the Echinacea isn't, and the NE Aster leaves aren't nearly as brown/yellow. How likely is it that plants in other beds are afftected?
Howard County Maryland
Expert Response
Unfortunately, yes, that usual leafy growth on the Echinacea flower is a symptom of Aster Yellows disease. There is no cure for it. You should remove and discard the entire plant to help prevent the disease from spreading. It is not necessary to remove any of your other garden plants if they don't have similar symptoms. Some common weeds like wild carrot, dandelion, thistles, ragweed, marestail, and pineapple weed can be symptomless reservoirs for Aster Yellows and should be removed if there are any in the vicinity.
The aster plants look like they have typical damage from Chrysanthemum Lace Bugs. These small sap-feeding insects are usually found on the undersides of the leaves. We would need a closer image of the leaves to confirm, but they are very common on asters (as well as goldenrods and mums). Usually, asters with lace bugs will be fine in the long run. No pesticide use is needed to manage the lace bugs in most circumstances, and we would discourage the use of insecticides on plants such as asters, which support pollinators.
Chrysanthemum Lace Bugs shelter in leaf litter and other plant debris. While keeping leaf litter over the winter is beneficial for many organisms, it can also harbor pests like these. Therefore, around plants like this with symptoms of a pest, a thorough clean-up of plant debris may help to limit the overwintering population.
Christa
The aster plants look like they have typical damage from Chrysanthemum Lace Bugs. These small sap-feeding insects are usually found on the undersides of the leaves. We would need a closer image of the leaves to confirm, but they are very common on asters (as well as goldenrods and mums). Usually, asters with lace bugs will be fine in the long run. No pesticide use is needed to manage the lace bugs in most circumstances, and we would discourage the use of insecticides on plants such as asters, which support pollinators.
Chrysanthemum Lace Bugs shelter in leaf litter and other plant debris. While keeping leaf litter over the winter is beneficial for many organisms, it can also harbor pests like these. Therefore, around plants like this with symptoms of a pest, a thorough clean-up of plant debris may help to limit the overwintering population.
Christa
