History of Knock Out RoseWilliam Radler Develops Hybrids That Are Knockouts By STEWART DEMPSEY From the July 9, 2006 edition of the Milwaukee Journal Sentinel It is hard to imagine a garden without roses. Their captivating beauty and lore are entwined in the hearts and minds of gardeners everywhere. So strong is the connection to this flower that gardeners would often spend more time and effort growing their roses than any other flower. But today, in large part because of one local man’s lifetime work, we can enjoy the beauty of roses with little of the effort once required. William Radler is responsible for many of the easy-to-grow new roses that are extremely disease-resistant, drought-tolerant and ever-blooming. In 2000, the All America Rose Selections committee named Radler’s original red Knock Out shrub rose as one of its winners and it quickly became the best-selling new rose on the market. Last year alone, some 3 ½ million Knock Out were sold, a total only this rose can claim. Radler’s Pink and Blushing Pink (a paler version) Knock Outs followed to equal acclaim. And Radler’s Rainbow Knock Out was just named an All America Rose Selections winner for 2007 and will be available next year. Radler spent his earliest years living with his family at 7th and Burleigh streets in Milwaukee. They were living in Whitefish Bay when he bought his first rose at a local A & P store with money he saved from his allowance when he was 9. His parents warned him that the plant would not survive the winter. Radler was confident it would, and the following year the plant thrived. From this early fascination, he developed a lifelong passion to develop and improve upon the rose. He went on to earn a degree in landscape architecture and served as the director of Boerner Botanic Gardens, all the while working on breeding roses as a hobby. Hundreds of Roses He now is a full-time rose breeder. His 1 ½ acre lot in Greenfield with its hundreds of rose bushes is his laboratory. In 1992, when he moved to his current home and garden, it was the yard and not the house that drew him to the property. He calls it the Rosarium. His basement is a facility for developing new roses and an incubation area for seedlings waiting for evaluation and possible inclusion in the outdoor Rosarium. These roses are tested and evaluated for disease resistance, repeat blooming, winter hardiness, resistance to insects and many other desired qualities. “I keep on selecting the best and continue crossing and crossing,” he says. “There are five hundred or more rose seedlings in the basement at any given time.” What does he look for in a rose seedling? The three most important characteristics at this early stage are breaking, habit and flower. Breaking is how, when and where the plant naturally sends out additional shoots from the main stem. Habit is the overall growth pattern of the plant (dense and bushy, or tall and spindly, for example). Flowers are rated on color, size, petal count and fragrance, among other things. Initial evaluation is critical, but some characteristics will change once the plant is grown outdoors. Developing a rose, even for someone with a horticultural background, is not an easy task. It takes a rare individual with the skills to recognize what he is looking at, and someone with an enormous amount of patience. At its introduction, Knock Out set the standard for Black Spot resistance and repeat bloom. This beauty has single, bright flowers all season that seemingly float above dark green, lustrous and disease-free foliage. Knock Out is winter hardy, and is self-cleaning (no dead flower removal is necessary). Its path to market was long and painstaking for Radler. “The very first crosses I made were in the 1970s,” he says. “Knock Out first saw the light of day in 1989. Knock Out was the only seed in a hip from a reluctant female.” It can take years to get the right crosses, and there are so many factors including weather, temperature, viability of seeds and genetic unpredictability that can impede the quest for the perfect rose. Making it disease-free To ensure disease resistance, the roses in the Rosarium are inoculated with disease pathogens. “I encourage disease on the property,” says Radler. Infected leaves are dried and ground in a blender then spread on the healthy plants when the leaves are wet. Overhead watering during the growing season guarantees the spread of disease. Resistant plants are easily observed and documented, then used in future crosses. “In the fall of the year disease and insects are at their peak. Does a rose still look great? It has to look good. That’s what people are looking for,” he says. The plants are further tested and analyzed by the companies responsible for propagation and commercial sales, such as Conard-Pyle Company/Star, the company testing and producing of many of Radler’s introductions. This year’s introduction is Bright Eyes. It is an upright, pillar-type shrub rose that also can act as a medium sized climber, suitable for smaller gardens. Its flowers are a delicious salmon-pink with a lighter central eye. In addition to superior hardiness and disease resistance, Bright Eyes is a repeat bloomer and has a lemon-spicy aroma. Other recent introductions besides those in the Knock Out series include Carefree Sunshine, and Ramblin’ Red. Some of the roses credited to Radler actually are mutations of his roses. And what does Radler say of his success? “I’m overwhelmed,” he says. “I can’t believe this has really happened to me. What started as a hobby for me has resulted in what has been called the most sought-after rose in the country. I’m beyond proud. “But what’s truly wonderful is that something that has brought such joy to me has also helped gardeners who never thought they could grow roses.”

Double Knockout is a good rose for a 'non rose person'. Plant them in full sun away from competition with tree roots. You will need to fertilize a couple of times a year (Osmocote is fine) and water in the summer, plant them where you can reach with a garden hose. Our soil is heavy red clay, roses (including Knockout) do better when organic material is added as a top dressing. If you only add compost or potting soil to the planting holes you'll get a 'bathtub' effect where your roses are sitting in water. Planting in a raised bed to improve drainage is a good idea but for only two roses I wouldn't go that far. I'd plant them in your normal clay soil then add compost (bagged cow manure available at Home Depot) topped by mulch. Two or three inches of shredded pine bark or hardwood mulch deters weeds and holds moisture. In spring you will need to prune a bit to shape up the bushes (they can grow quite large if left to their own devices).

I enjoyed reading, but saw only mention of climate causing difference in disease-resistance. Actually a much more important problem is that there are so many different strains geographically, that BS resistance in one location can mean absolutely nothing in another. This is why the Vigorosa roses are reliably blackspot resistant--the breeding program includes testing with a variety of BS strains. It would be really helpful to organize this discussion by states, etc. Secondly, I am wondering how many have heard that organic gardening techniques actually do more for roses in resisting disease than spraying in many cases. In a truly organic bed (no chemical fertilizers or pest & disease sprays) the soil organisms that thrive and multiply tend to push out or decrease the populations of pest fungi & bacteria. I sure hope this works for me as I have just bought a new home and am in the process of preparing a large rose garden.

I like sunny Knockout. Sure there are better roses but it grows well for me and always gets a comment from those going through my garden. So far it appears to be more disease resistant than most roses and it's always in bloom even though the blooms don't last long. But then, I grow roses for garden viewing and not for cutting or arranging. As with the other Knock Outs, I recommend them to first time rose growers to get their feet wet. Successfully growing them usually leads to expanding to other types. For this reason I believe the Knock Out line has helped the hobby. A neighbor who "can't grow roses," after seeing mine and asking questions, picked up one and now is growing a few hybrid teas and other shrub roses. She gained enough confidence with the Knock Out she tried others and now has learned "She can grow roses." For no other reason Knock Out has earned a place in the family of roses.