Double Knock Out® Rose gives you a classic full rose flower with the toughness of the original. Rosa 'Radtko' came from the same cross that produced Knock Out, and it carries double cherry-red blooms that look like a traditional rose while resisting black spot just as well. It grows 3 to 4 feet tall and wide in full sun, hardy from Zone 5 through Zone 11.
Bloom runs continuously from spring to frost, and the flowers carry a sweet fruity scent that the singles do not have.
Knock Out roses were bred for disease resistance first. They hold clean foliage through humid summers with no fungicide, bloom continuously without deadheading, and need nothing beyond a hard cutback in early spring. That combination is why they took over the landscape trade.
New growth emerges with a purple cast before maturing to deep green, and the foliage takes on purple tones again in fall. It is slightly more winter hardy than the original. Cut back by about a third in early spring. Shipped on its own roots.