Insecticidal soap is very good. You can get it at most garden centers. Miracle grow wont harm the butterflies unless it was to get on them, for instance, if it was granular, and they were to walk across it, as a caterpillar. It can burn us, so I am sure it would burn them.

You can also smash as many pest insects as you can with your fingers, or use a wet wash rag, and you could put some soap on it too. Dish soap is fine to use, also but it can harm sensitive plants, especially if it has anti bacterial ingredients which will often put spots on the leaves.

Susan,
First of all, Welcome!

As far as the aphids, what I do is hose off the buggers, and I mean HOSE 'EM OFF! Get out the hose and wash 'em down daily. Spray them with a strong spray. I had a really bad 'case' in the spring which means i was out there every day washing the plants. I am sure my neighbors thought I was nuts. ;P

As far as fertilizer goes, do not foliar feed. I do not recommend Miracle-Gro, personally, but hey~that's my own opinion. Something organic, perhaps? I know others use stuff like chicken manure...

I don't know about your tree. I've read that spraying Roses with a diluted milk solution is supposed to help with powdery mildew but I haven't tried it on our Roses...

I had the aphids reallllllly bad in late spring to early summer. They are still there, but at a more manageable number. I just hose them off as well, because insecticidal soap might harm the cats.

It's funny that the aphids were more prevalent earlier and now they aren't. Ladybugs and other beneficials at work? Possibly. Weather changes? Another possibility.

Susan