I won't use an insecticide of any kind if I can avoid it. It is a chemical, quick fix solution, and it is too easy to abuse it and use way too much.
You need to practice good plant hygiene. Clean up debris, spent flowers, leaves, etc. I have occassional beetles, caterpillars and the like but it is easy enough for me to pick them off. This is my third summer in Michigan and my plants do not seem to be drawing bugs.
I do however plant a lot of Marigolds in and among my flowers. 75% or more of what I grow are perennials, maybe they just do not draw the bad bugs?
For the occassional infestation of aphids I use alcohol and water. Half Isopropyl alcohol and half water in a spray bottle. You have to repeat spray, IF YOU DONT, you are just wasting your time!!!
If I have a plant that is acting like an insect magnet I try Neem Oil. AGAIN, REPEATED APPLICATIONS ARE A MUST! I never spray anything until the sun is setting or on a cool morning. In a gallon pump sprayer I use one tsp. Neem, 3 drops dish soap and lastly fill with water. I spray THE ENTIRE PLANT! You have to be thorough. If you don't get everything covered the buggies just slide over here and wait out the spray. Neem is safe to use as is alcohol.
I haven't used a chemical in over 45 years and I ain't starting now. I am beginning to think that they only make matters worse. I agree they build up, insects that is, build up a tolerance of sprays and it is like the bugs are begging you to spray them!! And we stupid humans happily oblige them!!!
