Question
I have large pots planted with annuals: potato vines, New Guinea impatiens, ageratum, alyssum.  Some of these plants in several pots have holes in the leaves, making the potato vine leaves look like lace and leaving holes in the leaves of the NG impatiens as well.  What is causing this, and what should I do?  I have sprayed these pots with chrysanthemum-based plant spray but don't know if this is the right thing to do, or what else might be better. Please advise.

Answer
Judy, the pesticide you are using is called pyrethrum. As you mentioned, it is derived from the chrysanthenum plant.

The product is 100% organic (non-toxic to humans and pets) and is highly effective against insects. I usually resort to this after trying insecticidal soap. My reason is that pyrethrum is a non-selective control, meaning it kills beneficials as well as invasive insects. But once the infestation gets bad enough, it is very successful in correcting the problem.

At this point, continue monitoring the plants every day. If the initial spray took care of the problem, the plants should recover. However, if the problem persists, you will need to apply the spray continually until the insects disappear. Just be sure to follow the dilution rates listed on the bottle.

Good luck, and please write again if I can ever be of assistance.

Regards,

Mike