I tried to switch the ornamental gardens to organic about 12 years ago.
Aphids will show up on most everything. Spider mites too and they have even killed dahlia plants. Mildew may be everywhere by late summer and black spot can work its way right from the bottom of a zinnia to the flowers. None of these problems add to any ornamental value and even"cosmetic" damage is too much on a flower. So, there was neem.
Neem was supposed to take care of all of this! It didn't. In fact, I developed a rash on both arms after spraying. Some kind of sensitivity ...
@hoodat likes neem. Everything in the veggies is organic. I use insecticidal soap on aphids, for example.
Last year, I grew Brussels sprouts for the first time. They are aphid magnets! I sprayed with both soap and a week later with pyrethrin. Pretty much the end of the aphids.
One plant was in a different garden and I sprayed it with neem. Dang near killed it!
I remember that I sprayed it in the morning and that is not the time I do my regular spraying. Late is best. With the neem, I guess I'd better treat it like the Palmolive dish soap I've used in the ornamentals and return the following morning and rinse the plants! Shoot.
Not giving up on neem but that Brussels sprout plant sure didn't enjoy being a part of the experience.
Steve
ETA: Natria brand is what I used. Probably says right on the label something about
not spraying in bright sunlight.