When deadheading the rose, the entire flower must be removed.

If a mid-season trim is in order, it is best done following a blooming period while in the resting phase.

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 treecutter.barted Reading Time: 3 mins. Feb 11, Learn how to properly prune roses during the summer treecutter.bar the Southwest Yard & Garden series.

Aug 09, Horticulturist Mary Kay Pope shows you how to properly prune your rose bushes in summer for optimal health. Cut back old wood about 30 to 40 percent before growth begins. Always cut to a live bud pointing away from the center of the shrub to encourage outward growth. Start deadheading after the first flush of flower, and continue throughout the summer to encourage more blooms. Species Roses, Old Roses, and Once-Blooming Shrub Roses.