Q.knockout roses
One of my plants has a white scaly stuff on the branches—plant is mostly dormant but just beginning to start getting some leaves. The scaly stuff was there before the growth started.
Don’t know what to do if anything?
Here is a good rundown on rose pests. http://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Visual%20Guides/Rose%20Problems.pdf. You may have scale insects which over-wintered on your canes. Here are some treatment options: http://www.clemson.edu/extension/hgic/pests/plant_pests/flowers/hgic2107.html