My usual reaction to aphids on the inflorescence, especially in bud, is to amputate. I don't think you can really make aphids stay away from the scene in a general way. They show up here at the oddest times in the oddest places, despite my best efforts, and my zero tolerance strategy for affected inflorescences. Here's one I let get way too far.
Much of the aphids' pervasiveness seems to be related to ant activity. Where you have aphids, you often have ants working alongside. The ants provide transportation to the aphids. So make sure there is no ant activity around the pot after you clean up a plant, or the aphids will most likely be back.
That said, you may get good results from treating the affected plant with imidacloprid after you clean it up to remove all visible bugs. There's a bit of a lag -- the product has to be taken up by the roots and incorporated into the growing parts for best effect. So the plant should be clean first. But that would be your standard chemical defense. You need to water it in carefully if you want it to work on containerized plants. It also seems to be a temporary deterrent to ants if they are passing through the soil.
These are outdoor plants? Be careful about moving them from protection into full sun. Maybe do it stepwise if you want to make any adjustments. I don't think that will solve the aphid problem, in any case. They go after plants in the sun here. Though you are wise to reconsider adjusting how you care for your plants whenever bugs show up, just as a way of adapting proactively.
