It took patience for Mother Nature to create the rose. And it takes patience-and skill-to improve on Mother Nature.

Tom Carruth, research and marketing director for Weeks Roses, is responsible for more than 100 introductions and holds 75 patents.

Tom Carruth makes roses. And when Carruth creates a rose, odds are it will be a winner. Literally. His plants have been picked 11 times for the highest honors in the rose world – the All-America Rose Selections – tying for the record among living hybridizers; all this done in the span of 14 years. Such stellar selections as Scentimental (1997), Julia Child (2006) and Wild Blue Yonder (also in 2006) highlight the range of color and type, but there are so many others that have proved to be winners in the market as well.

Carruth, who is the director of research and marketing for Weeks Roses, Pomona, Calif., has been creating and introducing roses for the company since 1988. His professional work in roses reaches back to 1975, although his passion for horticulture stems from his childhood in Texas. After he received his bachelor’s degree in horticulture and master’s in plant breeding from Texas A&M, he made his calling his career.

Through his research and development work at Weeks, Carruth has bred and crossbred thousands of plants, each one with the potential to be a hit with the garden center crowd or fall into obscurity before the bloom is off the rose (see sidebar, page 8). Those plants that don’t survive his rigorous trials – for whatever reason – simply don’t graduate.

Cinco de Mayo

“The new intros should perform well in most climates of the U.S.,” Carruth explains. “[They must] be different enough to attract attention and give Weeks a broad but unique selection; be naturally clean and vigorous enough for success by any gardener; be floriferous and fragrant in a way that will attract even non-rose lovers; and look good enough in the garden to stand up against other shrubs, even when it’s not in bloom.” That’s a lot to ask of a plant, but that’s what is required to make a sellable and successful rose.

The faves

Carruth’s keen eye for quality and his sense of what makes an outstanding plant – as well as what will succeed in the market – has led to such favorites as Cinco de Mayo, which received AARS honors in 2009, and Hot Cocoa (AARS 2003). Carruth’s creation Betty Boop won AARS recognition in 1999, as did Fourth of July. But not all of Carruth’s successes are AARS winners. He holds patents on 75 plants, and has more than 100 introductions to his name.


Market favorites include Home Run, a seedling of Knock Out with increased resistance to black spot, as well as powdery and downy mildew; and Pink Home Run, a fortunate sport of its red-blossomed parent. Purple Splash, a flashy, purple-and-white-striped climber with a light apple fragrance, was introduced this year. A dreamy, hybrid tea with full and shapely, apricot-cream blooms was named for Marilyn Monroe in 2003.

Chihuly, a dazzling floribunda with a mild, tea fragrance, features the hot colors favored by world-famous glass artist Dale Chihuly, for whom the plant was named. Another floribunda, blessed with a bold, cheery color combination of yellow red and pink stripes, exudes a strong, fruit-and-citrus fragrance. This selection was named for comedian George Burns in 1998. A bold, robust, hybrid tea named Legends, which boasts enormous, ruby-red blooms, was evaluated with the help of Oprah Winfrey, who chose this rose to pay tribute to the women honored in Winfrey’s Legends Weekend in 2009.

Julia Child

Betty Boop

Marilyn Monroe

Among rose types, Carruth says his personal favorite is the floribunda: “Since they bloom in clusters, they give a lot more color to the garden. Generally, their habit is more compact and usable in smaller spaces, too.” But when he’s working on creating the next roses for Weeks to introduce, he must take all traits into consideration. Whether it’s disease resistance, bloom time, specific color or a special fragrance, he cannot limit his development efforts. “You can’t just choose one characteristic,” he claims. “That won’t sell the plant. It has to have a multitude of good qualities to appeal to people.”

What’s not to love?

Roses sometimes can be a tough sell. Many have the reputation of being divas, requiring special and expensive care that time-strapped gardeners cannot provide. Others are advertised with the implied promise of no maintenance required, a claim that’s too good to be true. As it does for most plants, the truth lies somewhere in the middle. Although sales of rose plants to home gardeners has remained relatively stable – few shoppers can resist the allure of a blooming rose plant – landscape professionals have been somewhat hesitant to spec them.

According to Carruth, however, they shouldn’t be. “With careful selection,” Carruth claims, “there’s an ever-growing group of roses that break the mold of roses being high maintenance, fussy queens of the garden. There’s a world beyond the one boring pink rose that everyone gloms onto now.”

Carruth suggests that landscape pros “utilize your local public rose gardens to see what’s coming up that performs well in your area.” He continues, “Break out of the mass-planting rut. Throw climbers on the wall, stuff some roses in your other shrubs or perennials and think of using tree roses as a ‘second story’ in the garden.”

How it happens

Creating a new rose is as simple – and as difficult – as one would imagine.

The basic biology of creating a plant – pollen + stigma = new rose – is about as simple as it gets. Birds do it; bees do it. But creating a specific type of rose, say, breeding for fragrance, or extended bloom, or unique color, requires much more than an accident of nature. It takes imagination and patience, meticulous record-keeping and thousands of seeds.

And time. It can take about 10 years from the moment pollen connects with stigma to a finished, named, marketable rose. In Tom Carruth’s breeding program at Weeks Roses, Pomona, Calif., more than 850 crosses are created each year, each one with the potential to become the next All-America Rose Selection. Not every one makes it, of course. Seed from the crosses – about 200,000 seeds annually – are planted and carefully tended until germination, which has about a 40 percent rate of success.

Within about a month to a month and a half after germination, the very small, young plants begin to flower. Even at this stage, the flowers produced show enough of the eventual adult characteristics (flower color and petal shape, for example) that it’s possible to begin evaluation. Those plants that show any sort of disease susceptibility are culled, and the number of plants is narrowed even further.

From the 200,000 seeds, only about 800 to 1,000 new roses make it through the evaluation process in the first year. The most promising of these are marked for further propagation and evaluation. During July and August of this first year, propagating material from the best candidates is collected and grafted onto rootstock at the company’s growing facilities in Wasco, Calif., where the young plants are field-tested.

The following growing season, the budded seedlings are inspected and judged twice a week while they’re in bloom. What do the evaluators look for? Disease resistance is one important quality, as are flowering capacity, flower form, finish color, rebloom, growing habit and vigor. Fragrance and novelty also are considered; what makes a rose stand out in trials will make it stand out on the market.

This procedure continues for another three to five years. The most successful candidates are grown and evaluated in greater numbers, and less-than-stellar plants are eliminated. Eventually the field is narrowed to 10 or 12 varieties from a high of 850 original crosses. But the best of the best are still not ready.

The most promising of the remaining few are tested even further in the All-America Rose Selections (AARS) trials, which places roses in 15 test gardens in varying climates throughout the country. Evaluation responsibilities are transferred to the AARS judges, who observe and rate the plants according to strict AARS guidelines (see “One and Only,” page 10). After two years of strict AARS trials, only three or four new varieties will be introduced into commerce. (Remember that we began with about 850 possibilities.) And if a rose or two has performed outstandingly, it may be conferred with the title All-America Rose Selection – the gold standard of roses.

Growers need to get in on the fun, too. Incorporating a rose program can reap benefits, as Carruth explains. “Few other plants can offer the long-season bloom cycle of roses,” he says. “That translates to a longer sales season, as well.”

What’s on tap

With so many popular roses to his credit, what’s next for Carruth? More roses, of course. After so many years of creating exquisite plants, Carruth says, “I’ve yet to see the perfect rose. But, then again, if I did, it might be best to hide it until my near-retirement.”

For now, he says, “We’re working on shapely, super-clean plants with fragrant flowers with a form that looks more like what people expect a rose bloom to look like,” he says. “And it should flower its guts out with colors that look good throughout the bloom cycle, dropping the spent blooms clean.

“[Plus], it should have very abundant, attractive foliage that compliments the flower color, and it should live through winter without cover, be propagated on its own roots, look good in a container, flower early and often … and be novel enough to catch the eye and be named in a way to encourage sales. Easy enough!”

Easy enough for a lifelong, self-described plant freak, whose roses are known the world over. Giving all due respect to Mother Nature, Carruth has taken roses to a whole new level.

Sally Benson is editorial director of American Nurseryman. She can be reached at