Most famous rose born, bred and still living in Wisconsin

Name the first rose that comes to your mind.

I bet you said Knock Out.

That’s because not only is Knock Out probably the most famous rose, it might be the most famous modern plant. And it hails from none other than Greenfield, Wis.

It was 25 years ago that the first Knock Out rose was introduced. Bred by Will Radler, a University of Wisconsin graduate who worked for the Milwaukee County Parks Department for 26 years before becoming the director of Boerner Botanical Garden in Hales Corners, Knock Out was revolutionary.

Prior to its arrival on the scene, roses had a reputation for being needy, disease-prone and difficult to grow. Radler developed an interest in roses as a teenager, and by 1974 he was formally breeding them with a goal to producing low maintenance roses. And in 2000, the first rose he introduced was the original Knock Out.

A rose that bloomed for an exceptionally long time, didn’t need a chemical regimen to keep it looking healthy and had excellent winter hardiness was unheard of until Knock Out came along. It became the standard by which an entirely new category of landscape roses were judged, and today there are hundreds of roses that meet the same criteria.

There is a whole family of Knock Out roses, many bred by Radler. In colors that range from the original red to pink and coral and yellow and white, and double and single flowers, they offer almost any color a gardener could want.

They are, however, missing one attribute — scent. Only a couple offer a light scent, which is not an insignificant shortcoming. I think of Knock Outs and their landscape rose brethren as flowering shrubs rather than the perfect rose, and when taken in that context they rise to the top.

Knock Out roses can be found growing everywhere from vast estate gardens to big-box store parking lots, and there aren’t a lot of plants you can say that about. In fact, Knock Outs are so ubiquitous that they have been accused of being especially prone to rose rosette disease, which causes elongated and distorted growth. All landscape roses are susceptible to the disease, and as it turns out, more Knock Out roses are infected because there are just that many more Knock Outs being grown, not because they are more susceptible to it.

According to Radler’s website, the original Knock Out rose is still alive and well, and you may be able to see it at a tour of his two-acre garden known as Rose Innovations. Radler typically opens the garden, which features plants of all kinds, including many he has bred, a few times each year.

If you can’t get to Radler’s garden to see the first Knock Out rose, don’t worry; you can see its progeny at gardens far and wide where gardeners of all stripes have embraced them as an easier-to-grow version of perhaps the most beloved plant in the world. More than 150 million Knock Out roses have been sold since Radler shared it with the world a quarter century ago.

Not so shabby for a gardener from Wisconsin.