Also they hate vinegar.
Use 40 parts water to one part dish liquid. Put it on in the shade,. let sit for about 30 minutes and then hose off again.
The best aphid killer is a trap that does not require any chemicals on the plants. Here is a photo and some instructions I hope will help. It is vaseline on a yellow cup with a tack to hold it on the stick. They are attracted and get caught and trapped. YELLOW is important.