Rose leaves and stems often turn red when they first emerge and mature to green. However, if the stems of the roses are becoming distorted and the thorns grow large, deep red and soft and witches brooms form you have the mortal disease rose rosette. The rose must be dug and all parts bagged and put in the trash. It is best to do this asap so it does not spread to other roses. Best And Happy Yardening, Nancy.