Is this asters yellows or something else? - Ask Extension
This is a brown-eyed susan transplanted to a sunny spot in the spring. I chopped it back in early July to keep it from getting too tall. This is the...
Knowledgebase
Is this asters yellows or something else? #879177
Asked July 29, 2024, 8:53 AM EDT
This is a brown-eyed susan transplanted to a sunny spot in the spring. I chopped it back in early July to keep it from getting too tall. This is the result. I also chopped other brown-eyed susans in another part of the yard at the same time and they are fine, however, I noticed that other brown-eyed susans near this plant were starting to get similar growth. Thank you.
Talbot County Maryland
Expert Response
Both Aster Yellows infection (a virus-like pathogen) and herbicide exposure can create symptoms that look like this, and we can't determine from the pictured symptoms which may be responsible here. Was any weed killer used in the area in recent weeks, or perhaps in a nearby yard that might have drifted over on a breeze (especially if applied on a hot day)?
If Aster Yellows is the culprit, be sure to trim this plant last, or sanitize pruner blades before moving to healthy plants, since the pathogen might contaminate sap residue on the tool and infect other plants. (Generally, the pathogen is moved from plant to plant by leafhoppers feeding on the sap of infected plants. There is no practical way to exclude or prevent leafhopper feeding that would also not impact the plant's benefit for wildlife.)
Aster Yellows is incurable and affected plants will eventually decline and need removal. Herbicide injury sometimes can be outgrown by the plant, but not always. If new growth continues to look abnormal and deformed (if the plant produces any new growth during the rest of summer), then you can assume recovery is not likely and should plan on plant removal and replacement. You can replant in that case, assuming there aren't concerns about any herbicide residue in the soil or mulch from a source of contamination.
Miri
If Aster Yellows is the culprit, be sure to trim this plant last, or sanitize pruner blades before moving to healthy plants, since the pathogen might contaminate sap residue on the tool and infect other plants. (Generally, the pathogen is moved from plant to plant by leafhoppers feeding on the sap of infected plants. There is no practical way to exclude or prevent leafhopper feeding that would also not impact the plant's benefit for wildlife.)
Aster Yellows is incurable and affected plants will eventually decline and need removal. Herbicide injury sometimes can be outgrown by the plant, but not always. If new growth continues to look abnormal and deformed (if the plant produces any new growth during the rest of summer), then you can assume recovery is not likely and should plan on plant removal and replacement. You can replant in that case, assuming there aren't concerns about any herbicide residue in the soil or mulch from a source of contamination.
Miri
