San Antonio Express News
Gardening, ETC.
Sunday, May 23, 2004
It has been called the perfect landscape shrub. Virtually disease-free, "Knock Out" rose has received the Texas Superstar designation by horticultural experts at Texas A&M University.
According to Dr. Steve George, Texas Cooperative Extension horticulturist in Dallas, Texas A&M presents the title to plants that have undergone rigorous field trial testing to demonstrate their durability and beauty, with minimal maintenance and maximum protection for the environment.
“Knock Out” was first introduced in 2000 and was hailed a “breakthrough shrub rose” by the All-American Rose Selections because of its exceptional disease resistance and hardiness. It was one of three roses to win the prestigious AARS award for outstanding garden performance in 2000.
The rose was first brought to the attention of scientists by Dr. Brent Pemberton, a rose researcher with the Texas Agricultural Experiment Station at the Texas A&M University System Agricultural Research and Extension Center in Overton.
“I have had it in field trials at the Overton Center since 1998,” said Pemberton. “From the beginning, this rose was special. In a field trial where no disease controlling fungicides were used, “Knock Out” roses retained their foliage in stark contrast to the other roses around them.”
During a four-year research study at the Texas A&M University System Agricultural Research and Extension Center in Dallas, scientists found “Knock Out” to be one of the finest landscape roses that they had ever tested. During testing, no pesticides of any kind were ever applied.
“It has proven to be almost resistant to black spot, the fungal disease that is the scourge of roses across much of the United States,” said George. “It is also resistant to powdery mildew and aphids. It is cold-hardy throughout the state and will grow in a wide range of soils (even highly alkaline clays) and is very heat- and drought-tolerant once established.”
The fluorescent, cherry-red blooms begin in spring, and continue to provide color until the first frost. During the winter months, orange-red rose hips provide added winter interest. It grows well in planting zones 4 through 9 and will be five feet high by five feet wide when mature.
According to Dr. George, “Knock Out” is extremely easy to grow, even for those brand new to gardening, and is so pest tolerant that almost never will pesticides need to be applied.
“Simply locate the plants where they will get good air movement over the leaves and receive eight hours or more of direct sun each day,” said George. “Then incorporate three to four inches of finished compost into the soil prior to planting. Keep the soil surface covered with three inches of organic material year round.”
“If someone tells me that roses are too hard or need too much care, I tell them that this rose was made just for them,” said Pemberton. “This is one of the toughest roses I have ever grown, and it will reward the gardener with years of beauty with very little care.”
The Texas Superstar effort is one of the Texas A&M system’s most innovative and successful horticultural research and Extension programs, said George.
“Only the best adapted, highest performing and most pest-resistant plant materials are designated Texas Superstars, and should include the Texas Superstar pot label,” he said.
“Knock Out” previously was named an EarthKind rose by Texas A&M horticulturists. Only a few roses receive the EarthKind designation. Winners not only have to deliver outstanding landscape performance under widely varying soil conditions with minimal care and impact to the environment, but they have to be beautiful as well.
Dr. George states, “A key component of both the EarthKind and Texas Superstar designations is that a rose’s tolerance to pests is so great that you will almost never have to apply harsh pesticides in the care of these roses. EarthKind and Texas Superstar plants are the finest, most thoroughly tested and most environmentally responsible plants for use in Texas landscapes and gardens.”
After checking with several nurseries, “Knock Out” is available in the San Antonio area. To browse other high performance winning plants, visit the Texas Superstar website at http://www.texassuperstar.com/plants.html.
This article was submitted by Lynn Rawe, County Extension Agent-Horticulture, with Texas Cooperative Extension in Bexar County.
