Double Knock Out Roses are a group of shrub roses developed and bred by the Conrad Pyle Co. to be cold and warm weather hardy, require little maintenance, have a long bloom cycle and be disease-resistant. Double Knock Out Roses are hardy in USDA zones 4 through 9, thrive in full sun and require very little pruning or grooming. They produce a double ring of petals and bloom from spring through to the first hard frost in a range of hues from pale pink to deep cerise red.
Prune the rose bushes for shape and size in the early spring each year after the last frost has passed.
Remove up to one-half the height of the canes with loppers, placing cuts 1/4-inch above a leaf axil or bud to encourage branching and fullness. In younger plants, this will leave a foot or two of rose plant, which can look drastic but is safe. The rose will quickly produce new canes and leaf out.
Groom your bushes lightly to tidy them throughout the growing season as needed. Pull spent blooms that get lodged in the shrub canopy. Remove any yellowing or browning leaves and scoop up any fallen petals or leaves from the soil.
Water your rose bushes deeply after pruning to help them recover from the stress and prepare to send up new growth.
Feed with a high-quality organic rose fertilizer formula, such as rose tone or fish emulsion, in the spring.
Mulch around the base of the bush with a 2-3 inch blanket of compost or shredded bark. Mulch will feed the soil as it breaks down and will hold moisture to the roots of the rose.