 They should only be grown organically. When roses are loaded with pesticides or other toxic chemicals, the natural benefit is squandered. For best results, buy and plant well-adapted roses. Those on their own roots are usually the best choices. Planting, feeding, and watering instructions can be found on the homepage of DirtDoctor.com. For disease control in general, spray plants with garlic pepper tea. For insect pests, spray plants with orange or other plant oil products.