The most common Knock Out rose colors are red, yellow, pink and bicolor. The pink ranges from hot pink or almost red to true pink. The bicolor is called the Rainbow Knock-Out with the flower showing bright pink outside, then turning bright yellow near the center.
The Knock Out Rose thrives throughout much of the United States, except where winter temperatures fall lower than 20 degrees below zero. It is resistant to heat and disease and produces heavy blooms every five to six weeks from spring until the first hard frost. The Knock Out Rose was created by Wisconsin rose breeder William Radler and was first introduced in 2000.