Do Knock Out Roses Bloom All Summer?

History

• Wisconsin rose breeder William Radler came up with the Knock Out rose after 12 years of development aimed at improving the rose plant and instilling such qualities as disease resistance, drought tolerance, cold hardiness and repeat blooming. His efforts reaped success in 2000 when the Knock Out rose became the winner of the All-American Rose award. Knock Out set a record in 2000 as the fastest-selling rose in history when the new garden specimen sold 250,000 bushes.

Habit

• Knock Out roses bloom profusely from spring to frost. Labeled a shrub rose, Knock Out reaches a height of 4 feet and spreads to 3 feet. Grow Knock Out in full sun to partial shade most anywhere in the U.S. Knock Out roses are hardy from United States Department of Agriculture zones 4 through 9.

Pros

• Knock Out roses provide a showy display of fragrant, traditional rose scent throughout the growing season, making it a good candidate for use as a hedge. Radler's persistence in developing a rose free of disease has resulted in a drought-resistant specimen that shuns black spot, one of rose's most virulent diseases. Because Knock Out is self-cleaning, there is no need to deadhead this rose, thus reducing maintenance.

Cons

• With all Knock Out's pluses, it's difficult to find a minus. Since Knock Outs are classified as shrub roses, they tend to project a scraggly wintertime appearance. Compensate for this undesirable trait by planting Knock Out in the midst of low-growing evergreens.

Care

• Grow Knock Out roses in a fertile, well-drained soil in full sun to partial shade. As with other roses, water at the base of the plant with a drip- or soaker-type hose, preferably in the morning. Prune in early spring just before the onset of new growth. Pruning throughout the growing season controls size. Fertilize using a rose-specific product, following box directions for frequency and amount, then sit back and enjoy.