Taking care when selecting and planting roses is the best way to avoid most rose problems. Plant disease free hybrids and be sure to plant roses in well-drained, organically rich soil, in a sunny location with plenty of circulation.
Extreme heat and humidity are the two main causes of most rose problems. Stripping off old leaves each spring before new leaves emerge helps keep the two most common rose problems, mildew and blackspot, from attacking your roses.
Most roses can be grown without insecticide sprays. Because insecticides aren't selective, they kill the beneficial insects and microorganisms in your rose garden as well as the undesirables. Spider mites are known to attack plants that are regularly sprayed with insecticides. Easily wash aphids and most other insects away during regular watering. If you run across a stubborn insect, just give it the old gardener's glove treatment, pluck and squish!
Like any other plant, no rose is perfect. Pluck or snip the occasional "bad" leaf from your rose plants and just keep watch for a day two. If the problem is consistent, diagnose and treat it. However, don't schedule "rose surgery" for a single symptom.
Feeding roses is probably one of the most controversial subjects in growing roses. Some gardeners fertilize each time every-blooming roses show new bloom! However, feeding your roses should be the easiest part of growing roses. If you took care when you selected and planted your rose cultivars, in most cases you'll just need to add water at regular times. If you do fertilize your roses, do it sparingly; a small handful once a month to six weeks is more than enough to grow beautiful roses.
Help your roses to grow by enriching the soil in your rose bed with composted manure and mulches. Both are great amendments to poor soil. Mulch also helps keep soil loose and preserves moisture in addition to adding nutrients. However, when mulching roses, leave some free space around the canes to keep them from damping off and remember to replace old mulch with fresh mulch at the beginning of each growing season.
Roses are thirsty plants (all that time in the sun!). It's easy to tell when roses are getting too much water or not enough. If bottom leaves turn yellow and fall from the plant, you're watering too much. If your rose plant stops blooming, wilts, or drops healthy leaves it needs more water.
Deep watering results in deep root growth, which helps your rose plant survive drought conditions. A good rule of thumb for most plants is about an inch of water per week.