The Knockout Rose is a popular landscape shrub that provides continuous bloom and color throughout the growing season, from spring to frost. The shrub is a hardy, easy-to-care for rose bush and much less prone to black spot disease than other roses, according to the Louisiana State University AgCenter. There are several varieties of Knockout Roses. They all can be pruned or left unpruned. Does this Spark an idea?
Prune For More Flowers
Knockout roses grow to about 3 feet wide and 4 feet tall if left unpruned, according to marketing information about the shrub. But they can grow to as high as 8 feet tall, particularly in climates with long growing seasons, reports the LSU AgCenter. Pruning keeps the rose bush a more compact size and helps it to flower more.
Prune Knockout Roses once yearly in the spring. Use hedge clippers or loppers to prune the rose bush to one-third or one-half of its current height to promote healthy growth and plenty of flowers, recommends the Conrad-Pyle Co., the developer of Knockout Roses. It's OK that the rose bush is only 12 inches to 18 inches high after pruning, according to the company, which introduced the rose bush in 2000. Knockout Roses also are self-cleaning and do not have to be dead-headed.
Lopping off the rose bush to about 2 feet tall is another recommended way to prune the shrub. The rose bush should respond with vigorous growth and flowering and by fall might likely reach 5 feet tall.
But you don't have to prune Knockout Roses at all, if you don't want to, and they still will bloom, according to the North Carolina State University Cooperative Extension. They'll just be larger in the landscape and flowering might be less profuse.
Typically a Knockout Rose bush will produce an abundance of flowers in the spring. After that, the rose bush might have scattered blooms for the next five to six weeks. Then the shrub will likely produce another wave of abundant flowers. This cycle continues until frost.
There are seven varieties of the rose that include the Double Knockout Rose. The roses come in colors of red, pink, coral and yellow. They all reach the same size and have other same characteristics as the original Knockout Rose. All varieties are pruned the same way, or they can be left unpruned. Knockout roses are winter hardy in the United States to Zone 5 and heat tolerant throughout the country.
Tags: rose bush, feet tall, Knockout Rose, Knockout Roses, left unpruned, about feet
