Knowledgebase

Amsonia hubrechtii #931966

Asked May 17, 2026, 11:23 AM EDT

I planted 2 different Amsonia about 3-4 years ago in my front flower bed. That first year the A.hubrechtii got fuzzy plant hoppers - but the plant seemed fine; the A.tabernaemontana was unaffected. That same year, my R. hirta, in the back yard got asters yellow disease. It was removed. Since that first year the A.hubrechtii has not grown well - it yellows and dies much more quickly than the tabernaemontana and now the flowers are almost white - not lavender. My current thought is that the plant is impacted by the bacteria-like organism that causes asters yellow, but simply does not show the malformation typicallly seen. should the plants be removed? I thought the bacteria did not survive in the soil and if that is true, I would like to plant something else in its place. Please advise
Amsonia question 2026.pdf

Baltimore County Maryland

Expert Response

Hi, 

Did the A. hubrechtii ever look very green and bloom in pale purple? Perhaps it was just the root system on the plants when you planted them. Aster yellows, to our knowledge, does not affect Amsonia and it does not stay in the soil. Once the plant is removed so is the disease. 

We suspect that it is something abiotic and not a bacterium or virus. Did you use any pre-emergent herbicide in the garden beds? Did you treat the lawn with anything? Does this location drain well? 

Maybe a soil test would give us some more answers. Perhaps the pH is off or there is a key nutrient that is lacking (although the A. tabernaemontana is fine as you noted and most Amsonia is pretty tough, so this is perplexing). 

Emily


Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied May 18, 2026, 1:10 PM EDT

Loading ...