Good news for lazy rose growers: Another Knockout® rose will be available next year, and this one is white. William Radler, the Milwaukee breeder who created the incredibly popular Knockout roses in his backyard, told a group of Midwest Master Gardeners that a new white rose, expected to be called WhiteOut, will be introduced in 2009. Radler’s organization, Rose Innovations, is also prepping a new verbena, called Sweet Thing, for the marketplace in 2009.
Knockout roses are bred for gardeners with limited time and less inclination to fuss. They require no spraying and no winter cover, just a little fertilizer and water. Radler and his crew gave the master gardeners an inside look at how they develop these tough roses. Radler’s yard/lab, located in suburban Milwaukee, is planted with 1,400 roses, 500 of which are replaced each spring because they could not make the cut. To develop extremely hardy roses, Radler treats them in the worst ways possible. He waters from sprinklers at night several times a week to encourage disease. He intermittently dusts them with a powder made of leaves of other diseased roses. They get one treatment with fertilizer a year. Those that survive might become Knockouts, which also have to be self-cleaning, meaning they drop their petals naturally to keep a neat appearance, and, of course, they have to look good. In addition to the shrub-type roses, Radler is working on developing a sturdy, disease resistant hybrid tea rose.
A Knockout hybrid tea is still several years away, but the visit to Radler’s prompted some discussion among the master gardeners. Apparently some enthusiastic (fanatic?) rose growers don’t like Knockouts because they make gardeners believe roses are “easy,” said one of the master gardeners, who is a rose grower herself. But she liked the Knockouts because they introduced gardeners to roses–and once they were interested and had success with Knockouts, they could move on to other roses.