On a recent garden walkabout I discovered a small stand of Echinacea infected with Aster Yellows. It’s been many years since I last saw this issue in coneflowers: reassuring since many of our gardens are home to this popular perennial and reliable pollinator plant.
The disease is transmitted via leafhoppers. When the leafhopper feeds on an infected plant, it too becomes infected with the phytoplasma. The infection lasts the lifespan of the leafhopper. When the infected leafhopper visits the next plant, it transmits the disease via saliva.
- It takes 10-14 days for infections to show up in newly infected plants.
- You’re more apt to see this issue with coneflowers during cool, wet summers.
- There’s no cure beyond removing the infected plant from the garden and disposing it in the trash.
Fortunately, because many of us plant Echinacea for its ability to draw in pollinators and as focal plant with great splashes of color, we are likely to look at the flowers often during the blooming season and will, more often than not, notice the infection in its early stages.
It's a shame to have to destroy a plant. But, should your coneflowers succumb to the disease, know that you can replant next year, as the issue doesn't not reside in the soil, but in the leafhopper, which will be long gone come next spring. ~ Jennifer