When should I feed my knock out roses for the last time this year?
Feeding Knock Out Roses
I live in zone 5 Colorado. The last time I fed my rosebushes was the first part of September. It is way too late to be feeding them now if you are in a cold climate area. We want the roses to be gearing down to go dormant for the winter. If they are growing too hard when the deep cold hits it can kill the bushes. You can scratch in a couple tablespoons of super phosphate into the soils around the rosebushes. It moves slowly through the soils and gives them a kind of winter snack to keep the roots healthy.