To maintain a size of 3–4’ w x 3–4’ h, Knock Out Roses should be cut back once a year to 12” high. Check your rose bush from time to time in late winter/early spring, and when you start to see new shoots growing from the canes on your rose bush, that’s a good sign that it’s time to prune.
Jan 08, These roses do need some care, and that includes pruning. The best time to prune all types of roses is either in late winters or in early spring. This is the time when new growth starts. Fall is not a good time for pruning, as this could lead to the death of the plant. When it comes to cutting back a knockout rose plant, there are some things Estimated Reading Time: 4 mins.
Oct 07, Knockout roses are a relatively low-fuss variety that can make a welcome addition to any yard or garden, but they do require a little seasonal pruning in order to grow healthy and beautiful. Cut back your roses extensively at the beginning of spring, 96%.
Research indicates that Knock Out roses respond best if not cut back lower that 24 inches for the hard pruning in early spring, and more moderately in the fall. I’m surprised they have done well cut back as short as 12 inches from the ground.
For long-lasting, easy color, plant Knock Out roses. Low maintenance and disease resistant, they love to bloom. The original 'Knock Out' rose has cherry red single petals. 'Pink Knock Out' has beautiful pink single petals.
There are also double flower forms of both.