Last year, Marge boasted about her amazing roses.

“Those ‘Knock Out’ roses just keep coming,” she said. I was intrigued. But didn’t pursue the subject.

In 2013, I mentioned roses from France and without checking mistakenly wrote that Knock Out roses came from the famous House of Meilland. A reader sent me to learn more.

Knock Out roses are, in truth, American-bred, and not even from Texas or California. Would you believe Wisconsin?

Here’s the story. Little William Radler would visit his grandparents. Not much grabbed his attention at their house until he found their rose catalogs.

Those pictures excited him and he became absorbed in roses. He bought his first when he was 9, then began to acquire more. At 17, this Milwaukee-area teenager became a charter member of the new North Shore rose Society.

William Radler grew up to be Director of the famous Boerner Botanical Gardens, all the while collecting his own roses. He noticed that rose growers would collect to a certain point and then cut back on their hobby, or passion. They would run out of space or would realize that they were spending way too much time tending their temperamental plants.

Radler began to propagate his own roses, by cuttings or bud grafts: a cheaper way to acquire more plants. Because he’d perceived the hours rose growers spent battling pests and preparing their roses for winter, he decided to breed his own, aiming for maintenance-free specimens.

In the 1970s, in this northern state, he began to breed for zero winter protection. It was slow, with plenty of chances for failure; but he did produce hardy roses. From then on, he didn’t miss that winter-protection chore.

Next, he bred plants to resist black spot, a foliar disease which can strip roses of all leaves, making the plants unattractive. How to get rid of weekly chemical spraying? One way is to spray black spot-resistant roses with a mix of water and powdered foliage from infected leaves. Spread in overhead irrigation, this inoculated the roses. Any that persisted in being infected were removed from the garden.

Over any growing season, Radler has about 1,00-plus roses (it must be some yard!) He discards about 500 at the end of the season.

Meanwhile, he’s pollinating planned combinations of roses, gathering the seed-bearing hips, sowing, planting and potting seedlings.

One such hybridizing: Carefree Beauty with Razzle Dazzle, resulted in an outstanding rose. In 2000, it won the prestigious All-American Rose Selections Award That was the original Knock Out.

Here’s a compact shrub rose, 3x4-foot tall and wide, bearing clusters of red flowers from its first year. It doesn’t need heavy winter protection. It’s black spot resistant. It blooms all summer and into the fall. Spent petals drop off and scarlet hips form, so it doesn’t need deadheading. It lives in sun or part shade.

Plant Knock Out in ordinary, loamy soil. I would pamper it during its first year. It won’t attract insects such as Japanese beetles, but butterflies love it. It yields cut flowers for indoor bouquets.

Pruning? After the last hard spring frost, remove any dead wood.

William Radler hasn’t stopped with Knock Out. Double Knock Out is another, and there are pink and double pink roses. Try Rainbow, Blushing Knock Out or Sunny, which has yellow flowers. 

If I’d stopped to ask, I might have known sooner about these wonder roses. Try one and let me know your opinion.

Thanks, Marge!