After three or four weeks, change to a brand name rose food. Established roses should be fed every week from early spring to late August. On the premise that prevention is easier than a cure, spray once per week with insecticide/fungicide.
Fall or Early Winter
Change from rose food to 0-0-20 (straight potassium) for overwintering vigour. Let the last flowers go to seed; do not prune.
When the ground is frozen, (not too early, mid- to late November)hill up the rose canes with soil, which you have kept unfrozen for this specific purpose, to a height of 45 cm. Do not prune at this time, unless the canes are so tall they could whip about in the winter winds, thereby damaging themselves or disturbing the hill of protective soil. Leave as much cane as possible. In beds or in mass plantings, rose collars are a must, — they are easy to use and reduce the amount of soil required. Where collars are not used, the hill of soil, once frozen, should be covered with evergreen boughs after Christmas so that the soil remains frozen and does not thaw in mild spells.