Major pruning should be done in early spring, after the last frost in.

Most standard climbing roses are the exception to this rule. They typically bloom on old wood, so cutting them back in early spring would cut off new blooms. They should be pruned just after the flowers finish, although you can remove dead or unwanted branches at anytime.

Knock Outs tend to produce a lot of rose hips that inhibit flowering triggering dormancy, so trimming these off will keep your Knock Out blooming.

In the summer, prune rose bushes. Jul 26, Any heavy or moderate pruning of rose bushes is not advisable during the hot summer months. This is because once a plant has left its dormant stage and is already in the growth stage, the plant’s cane is full of sap. When one of the rose bush’s canes are cut, the sap leaks out. Losing too much sap will weaken the entire rose stumpcleanup.barted Reading Time: 3 mins.