Double Pink Knockout Rose Patio-TreeDouble Pink Knockout is grown for its CLEAR PINK semi double to double (twice the petal count of Knock Out) flowers that appear in clusters in great profusion from spring until frost. "Tree" roses are grafted plants, making them a more unique and exotic offering than standard landscape roses. Patio tree roses are cold hardy in our area. They may be left oudoors all winter, in pots or in the ground.