Proper trimming was the biggest thing that we did to start, the previous LCO was trimming with a hedge trimmer.....we use felco's . Then we took over the fertilization and pest control. They get hit with 8-10-10 or 8-2-12 Lesco ornamental and Palm fertilizers once a quarter. In between they are sprayed with two products, each a Micro nutrient package as well receiving cupro, bifen, dominion and recently for thrip season here we applied safari. The key to roses is to keep the pest and mildew off them and feed them more often by spoon feeding them at least down here as they will provide blooms almost the entire year if properly trimmed and feed.