Earth-friendly roses for tough climates

Roses acquired a bad reputation in recent years, as gardeners found they had less time to deal with the plant's queenly temperament. The pampering – notably of hybrid tea varieties, which are the most popular sellers – includes frequent spraying for bugs and diseases. These requirements did not endear roses to environmentally conscious gardeners.

"In the last five to 10 years, breeders realized that people didn't want to turn their garages into chemical labs," says Gaye Hammond, past president of the Houston Rose Society and national coordinator for the EarthKind Rose Research Program.

Home gardeners' changing habits have created a market for low-maintenance roses – those that require significantly less watering, pruning, fertilizing, and spraying for pests and fungal diseases. No rose is completely "care free," no matter what the nursery promises, but breeders are reintroducing traits that enabled previous generations of roses to survive adverse conditions.

These hardier varieties mean that, with a bit of preparation and knowledge, gardeners have a much better shot at growing roses. The real task is to cut through the growers' marketing hype and glossy catalogs to find varieties that have been independently tested.

Big market for low maintenance

Among the first to recognize the market for low-maintenance roses was Bill Radler, a former director of the Boerner Botanic Garden in Milwaukee. He hybridized a tough little shrub rose named Knock Out with cherry-red blossoms that won a prestigious commercial growers' award in 2000. Mr. Radler continues to add to the original Knock Out with a series of shrub roses that bloom in a variety of colors. His Knock Out line has become a huge financial success.

"Knock Out revolutionized rose growing," says Ted Mills, who for 30 years has been tending hundreds of rosebushes on his property in Chattanooga, Tenn. "That little rose brought more people into growing roses." Mr. Mills, known as the "Rose Doc," is a consulting rosarian for the American Rose Society (ARS).

The ARS is a nonprofit organization that supports 350 local societies concerned with rose growing. Its consulting rosarians are experienced gardeners who share their knowledge, at no cost, with the public. ARS members also test new rose varieties in their own gardens and reward the best-performing plants each year with the Members' Choice Award.

But scientific testing of roses did not start until 1996, when Steve George, a Texas A&M University professor, launched the EarthKind rose project. Using similar research and testing approaches used on other agricultural crops, Dr. George identified 11 roses in 2002 that would flourish in Texas despite poor growing conditions and practically no maintenance.

The news caused such a stir internationally that the Houston Rose Society raised money to expand the program to identify other varieties that would grow in other regions. Today, six universities in the United States, along with organizations and individuals in 23 states and four foreign countries, are looking to add to the 17 roses already certified as EarthKind, according to Ms. Hammond. (Radler's Knock Out "Cherry Red" is among the roses that earned the EarthKind certification.)

Roses never out of favor

Roses are known in practically every culture and have played a role in every major civilization and aspect of human life, according to Hammond. "The rose has been around for 34 million years, and along with the lotus and papyrus, it's among the oldest cultivated plants in the world," she says.

Although roses were grown by European peasants for medicinal use, "it wasn't until Empress Josephine began to monkey around with Mother Nature that growing roses was seen as an elitist pursuit," says Hammond. "It became a competition." (Josephine was Napoleon Bonaparte's first wife.)

The rose of choice for the past 60 years has been the hybrid tea, a genetic concoction that produced a tightly furled, multipetaled bloom on a single long stem, similar to the ones used in the florist trade. This is the classic cupped shape that most people think of when they hear the word "rose."

Breeders, in singling out certain genetic traits, created the flower equivalent of a labradoodle dog – a cross that results in a specimen that tends to have less resistance to diseases.

But the genus rosa includes far more than hybrid teas. "In the 1930s and '40s, everything was about the development of hybrid teas," says Keith Zary, a rose breeder with Jackson & Perkins in Somis, Calif., the world's foremost hybridizer of garden roses. "In the '50s and '60s, growers worked to improve the range of hybrid tea colors, and in the '70s and '80s, we were trying to improve plant vigor. In the '90s and now, we are looking at disease resistance and fragrance," two characteristics that were lost in the push to develop hybrid teas.

One of Mr. Zary's latest creations for Jackson & Perkins to reach the market is Mardi Gras, a floribunda rose with four-inch blooms in a blend of yellow, orange, and pink. (Floribundas are a modern cross between a hybrid tea and a polyantha – or many-flowered – rose.) He made the cross in 1997; it took 10 years to complete the trials in climates ranging from the extreme heat of the Southwest to the extreme cold of Minnesota. While hardiness is an important feature, consumers are more likely to be swayed by the photographs of Mardi Gras's vibrant blooms.

"The market is an important driving force," says Zary. "Fashion does play a big role" in which types of roses receive the most attention from breeders and nurseries.

With the rise of the green movement, gardeners are cutting back or eliminating pesticides and fungicides, and using less water. They don't have the time for many of the maintenance chores such as removing spent blooms or staking branches. So they are demanding plants that require less work, that enable them to spend their outdoor time relaxing in a hammock instead of on their hands and knees.

Beyond 'rows of soldiers'

Zary says landscape designers are currently rethinking how to use roses. Many people are familiar with public rose gardens, which generally grow the plants in soldierly rows, he says. This treats each rose as a specimen to be admired, but it doesn't offer home gardeners much inspiration on how to incorporate roses into the landscape with other perennials and shrubs.

For decades, roses have been viewed as best suited to cutting gardens, where the owner would cut blooms for arrangements and no one would notice any spotted leaves or bare branches. But few people today have the space for such gardens.

He suggests that homeowners become familiar with alternative types, such as climbers or shrub roses, which can offer vertical or horizontal accents in the garden. Some low-growing roses can also be used as a blooming ground cover.

"Gardeners should decide what they want the roses to do," Zary says. Instead of playing the delicate prima donna, "roses can be the structural backbone of a garden."

Tips for rose growers

Experts offer this advice for getting the best results when growing roses:
• Determine if you have enough sun. Most roses need six to eight hours of direct sunlight.
• Decide how much maintenance you are willing to provide. If the answer is “not much,” choose an EarthKind-certified rose or one of the antique varieties.
• Seek advice from local rose experts. A list can be found on the American Rose Society website.
• Test your soil. Local university extension services can help you determine if additional nutrients are needed. Well-drained soil is ideal.
• Give your rose plenty of space. They need good air circulation to ward off diseases such as black spot and powdery mildew. Planting too close to other plants or against a house or fence can cause problems.
• Water using a drip-irrigation method to avoid wetting the leaves, which promotes fungus growth.
• Provide a soil cover of three to four inches of bark mulch around the rose, but not touching it.
• Choose “own root” roses. Many roses are grafted onto the rootstock of another rose. If the plant dies back to its roots, the rose that regenerates will be true to the rootstock, not the preferred rose.