Knock Out® Rose TreeKnock Out's Color + Carefree Growth in Tree Form Why Knock Out Rose Trees? Rich blooms in abundance with no maintenance needed: Knock Out Roses have set the standard for bloom color, size, and adaptability. Now, horticulturists have bred a tree with the same characteristics. The Knock Out Rose Tree has raised the bar for disease resistance and is as carefree as they come. Hardy and reliable, your rose tree will bloom from early spring to the first