Marigolds + whiteflies

Asked September 17, 2019, 5:35 PM EDT

I have marigolds throughout my garden, including the raised vegetable beds. I've noticed an amazing number of what I assume are whiteflies flying off the marigold plants when I go to deadhead them, most especially since the rains. I thought marigolds deter whiteflies, but wonder if the August hot weather just gave me an amazing crop of the flies this year?

Benton County Oregon

1 Response

You might be right about the August heat. As plants become more stressed they have less resistance to invading insects. I have attached a couple of links for you if you are interested in determining which type of whitefly you may have. There are control measures included in the links. A basic management protocol is shown below:

"Keep plants healthy and watered according to their needs. Whitefly populations increase with high nitrogen levels: do not over-fertilize plants. Wash plants with a gentle stream of water directed to the underside of plants, or disturb foliage and vacuum adults. Prune back and encourage host plant refoliation. A combination of disturbing the foliage, vacuuming flying adults and using sticky yellow cards attractive to whiteflies provides some measure of control, but stay vigilant."

https://pnwhandbooks.org/insect/hort/landscape/common/landscape-whitefly