These symptoms could be the result of several different problems. Applying too much fertilizer or using a fresh manure that can burn the roots of the rose plants can cause stunted new leaf growth and curling leaves. Root damage from a burrowing mole or vole especially during hot weather will also show up as small and curled foliage. Another possibility is that an herbicide was accidentally allowed to drift onto your rose plants. I suggest a good, deep watering with a check for any animal burrows and if you did apply a mulch of chicken manure or some other barn yard manure pull it away from the rose plant now. You can also prune off the damaged sections of the rose plant to encourage healthy new growth. If the rose plant continues to decline, pull it out of the ground and check the roots for damage. You may lose the rose plant but doing a post mortem will help you to learn from your mistakes. Write back and share your discovery so we all can learn. Keep growing, Marianne Binetti