barbavon's Rose garden

I started my first rose garden 2 weeks ago. I’m looking for info and tips. We have clay soil so we worked compost, peat moss, manure into the top 12 inches of soil 12 years ago. Have grown a few rose bushes over the years in this plot. They did well, so we decided to go all out with all roses this year. The new plants are thriving, so are the aphids. I dust with sevin but its a never ending task. I would like suggestions for better control. The plot is on the south side of the garage wall and has full sun from 10 AM to dusk.