PACIFIC HORTICULTURE, Number 2 2000, PAGES 29-33
THE HIBISCUS REVOLUTION (3d page)
By Charles Black
growth habits to propagate for commercial distribution. We look for an upright habit, attractive and abundant foliage, a naturally branching response to pinching or pruning, good but not excessive vigor (to avoid soft floppy wood), and general good health and ease of cultivation. When we find a cultivar with these qualities and an exceptional flower produced in abundance, we make it part of our commercial propagation program. Our goal is to provide the public and other growers with the best of the many thousands of named hibiscus that have appeared over the last hundred years.
(We realized it would not be practical for us to hybridize for significantly better growth characteristics using the commonly available landscape cultivars. That would be a decadeslong process with no guarantee of success. Ross Gast made such an attempt forty years ago, when he began breeding hibiscus suited to Southern Califonia. He produced only one notable cultivar still in use, 'Ross Estey'.)
We decided to look at the thousands of show hibiscus in hopes of finding some that could become good landscape plants. After five years of testing and evaluating, we have identified one hundred cultivars that are reasonably good, less than thirty that we believe are without major flaws, and fewer than ten that meet all our specifications. Over the next decade, we hope to collect or hybridize other cultivars to join the exclusive "Best of the Best" list. Meanwhile, we have begun making the top one hundred available to garden centers and other growers, while maintaining a larger list of 'collector only" grafted cultivars that we produce on demand. (For a true collector, the blossom is usually the most important aspect of the plant, and we are happy to provide unusual and rare cultivars to those who do not mind their other shortcomings.)
Hibiscus for Containers
In Europe, breeders have concentrated on developing small, compact plants with many small blooms, to satisfy the demand for potted houseplants. These are also grown in the United States and are sold mostly in cold-winter regions. They are grown on their own roots, usually several plants to a pot, and are chosen based on their response to chemical plant growth regulators. When pinched and treated with a growth regulator twice, the result is a bushy, compact, attractive plant in a six-inch pot sporting plenty of buds and blossoms at the time it reaches the marketplace. The flowers are small and usually in solid colors, but the overall impression of a well-grown plant is pleasing and popular. These are 'disposable" hibiscus, seldom likely to develop into healthy, long-lived plants, though they are pretty and may last. for a season or two.
Through our evaluation process, we have also discovered fancier hibiscus cultivars that can be grown in six-inch pots. These are grafted selections with large, sophisticated flowers. They can be grown without growth-regulating chemicals, and can be expected to last for many years. They will outgrow the small pot within a year of purchase but, with care in watering and fertilizing, can be maintained in ten-inch or three-gallon pots indefinitely. They need one or more hours of direct sun to flower well, with temperatures in the 60s ÉF at night and warmer during the day.
Top Fifteen Hibiscus Cultivars
After ten years of evaluation, we feel comfortable in recommending the following cultivars of hibiscus. All have single (five-petaled) flowers, except as noted.
'Amber Suzanne' offers classic eight-inch, pink and white double flowers on a sturdy, full bush reaching six feet tall and wide. It flowers reliably, each flower lasting two days and is relatively tolerant of temperature extremes. AHS 'Hibiscus of the Year," 1993.
'Bonnie B', slow at first, eventually becomes a strong, attractive bush with heavily textured eight- to ten-inch blossoms, red-orange with a yellow edge, that can last up to three days if not in too much sun.
'Crimson Ray' is a well-branched shrub, with elegant eight- to nine-inch, maroon-throated, yellow flowers.
