imadacloprin danger to hostas

Asked September 1, 2020, 8:29 PM EDT

Will my hostas suffer from the imadacloprin drench to control the magnolia scale on my saucer magnolia? They are directly in the proscribed drench path.

Oakland County Michigan

2 Responses

I've done some research and I see no indication that hostas have any problem with the insecticide imidacloprid. I found some conflicting ideas on it's use for magnolia scale, however.

https://hort.extension.wisc.edu/articles/magnolia-scale/
https://hortnews.extension.iastate.edu/magnolia-scale
https://extension.umn.edu/yard-and-garden-insects/scale-insects

Please select insecticide carefully. Imidacloprid kills earthworms. It also can kill bees if there is any residual chemical in the flowers of your magnolia or surrounding plants.

Killing scale can be an onerous task due to it's lifecycle and self-protection. Good luck.

Thanks. I'll keep you posted.