White eyes, foot-wide flowers, maroon plants
With a little cross-breeding and some determination, Dr. Dariusz Malinowski, Texas AgriLife Research plant physiologist and forage agronomist in Vernon, is trying to add more colors to the world of hibiscuses.
Malinowski is working on breeding winter-hardy hibiscus in what started as a hobby about four years ago, but in the last year has been added to the strategic plan of the Vernon research program.
Commercialization of the flowers by Malinowski; co-worker Dr. William Pinchak, AgriLife Research-Vernon; and Steve Brown, Texas Foundation Seed Service program director, is a part of the research on non-traditional or under-utilized crops that have value because of drought tolerance.
The hardy hibiscus is a great candidate because it is a carefree plant. It doesn't have to be watered once it gets established, is low maintenance and has little disease or insect pressure, he said.
Malinowski said one objective of the breeding program is to create lines or cultivars with a range of colors. Presently, commercial cultivars come basically in three colors - white, red and pink.
"We have created so far many more colors, like lavender or mauve, different shades of fuscia and pinks," he said. "One flower we have, we want to have an almost burgundy color. Another is lavender with a big flower, big petals. And we have a plum color that is rare in hibiscus."
The goal is to have at least 11- to 12-inch diameter flowers, Malinowski said.
"We can manipulate the color and still maintain the large flowers with nice texture," he said. "We also can combine the trait of a large flower with dual colors and nice texture. That is an important value for the next step of the breeding program, to create dual colored flowers."
Malinowski said one of the species used in the breeding program is a Texas native called Texas Star Hibiscus. The value of this particular species is it provides a very different shape of flower and very different position of pollen on the stigma than found in traditional cultivars.
With the pollen allocated on top of the stigma, it gives the flower a very tropical look, he said.
"We have successfully incorporated this trait to several of the breeding lines," Malinowski said. "They are similar to the Texas Star Hibiscus, but with much larger petals, much bigger flowers, and different colors."
Another objective of the breeding program is to create cultivars with dark leaves, he said. Already he has been able to produce one plant with maroon leaves, almost brown in color.
"Such plants do not exist on the market today," Malinowski said, adding that is what his breeding program is all about - trying to provide consumers with something different that survives the winters in this region.
The way the maroon-leaved plant was created, he said, was to use some of their hybrids with darker, reddish stems, and make multiple crosses among them.
"Within two generations by crossing them, we were able to create a plant with not only dark stems, but maroon leaves," Malinowski said.
Larger flowers and different colors are a big part of the program, but now Malinowski is also trying to change the traits of the eye of the hibiscus.
"Our new objective is to create red flowering hibiscus with a white eye," he said. "Usually hibiscus flowers have a dark red or maroon or brown center eye, but rarely do they have a white eye. Last year we found a plant with large soft-pink flowers and a white eye. We are trying to transfer the trait of the white eye with the red flowering types."
Malinowski made this cross just recently. He said now the plant is expected to double up with fruit or seeds. It will take about six to eight weeks from pollination to collect mature seeds. Later, those seeds will be planted again with the hope "one or more of them will have the trait of red flowers with white eyes."
Breeding a line or new cultivar of winter-hardy hibiscus takes several years, Malinowski said. The cultivars he develops should be commercially available in two to three years in major garden centers.
In 2009, Malinowski produced about 600 crosses of hardy hibiscus and planted about 2,500 hybrids for evaluation during 2010.
To date, about 50 percent of the hybrids have bloomed and there are several of them with exceptional commercial value, he said. These lines will be vegetatively propagated and evaluated.
One goal left for the breeding program is to create a blue flowering hibiscus, Malinowski said.
The hibiscus can basically be grown from South Central Texas to Canada, as long as the required winter period is long enough for them to go dormant after the first frost, Malinowski said. The plants re-sprout from the root the following spring.