Breeders Turn the Heat Up a Notch

Euphorbia Diamond Frost.
Euphorbia Diamond Frost. (Chris Brown Photography)
By Adrian Higgins
Thursday, May 17, 2007

May is the month to plant containers and garden beds for the long summer ahead. The market shift from simple gardening to outdoor decorating has produced a rich array of plants to play with, so we won't be churlish about this trend.

We may not need 60 patented varieties of calibrachoa, but one could argue we do need 10 of them. With their small, bell-like blossoms in shades from orange to hot pink, the calibrachoas produce endless waves of flowers from now until October on pert, mounding plants. Grouped with a 21st-century arkful of other heat-loving seasonal plants from bananas to alocasias, they have suddenly made the impending sticky Washington summer not only bearable but festive.

These plants are designed to do well for casual or novice gardeners who want some plants to decorate the patio, deck or balcony. They need little more than basic care beyond soil preparation and a commitment to watering and feeding. In return they perform admirably all season, flowering or bulking up in leaf. Avid gardeners can lift and store them year to year, but the nursery trade knows well that most people will toss them come October. It would be easy to decry the fact that we must now add horticulture to the other facets of our throwaway society, except the frenzy is drawing some gifted breeders and nurserymen with something to contribute.

Barry Yinger founded Asiatica, a nursery in Lewisberry, Pa., as a source of esoteric plants from Southeast Asia for connoisseurs. But he is now also devoting his plant-spotting talents to tropicals, and this year through Homestead Gardens in Davidsonville, Md., he is introducing a line of caladiums that he says brings the familiar leafy plant to a new level.

He plans 17 variety introductions this spring at Homestead and other independent nurseries in the Washington area. Yinger, who has opened a nursery in Thailand, said the caladiums were bred for the Thai royal household for more than a century but were unknown to western horticulture. The varieties, which he has named Thai Glamour Caladiums, feature new colors and color combinations. Raspberry Fudge has deep-plum-colored leaves with black veins and leaf stalks; Tutti-Frutti has asymmetric variegation in green, rose and silvery pink; Candied Apple has large, extremely glossy leaves in deep rose red and crimson; Cotton Candy is a clear pink with white veins; and Chocolate Cherries is a deep red to mahogany with black veins. A variety named Peppermint Stick is white with scarlet veining.

Beyond the arresting colors, Yinger said it is the leaf thickness -- gardeners call it substance -- that makes these plants different. Caladiums are known as shade annuals. But the royal Thai varieties are tough enough for sunny locations, Yinger said, as well as the wind and rain that go with summer storms.

He recommends combining them with fine textured annuals such as, yes, calibrachoas, scaevola, bacopa, the Diamond Frost euphorbia or "anything spiky or grassy."

Time and experience will judge these caladiums. Certainly the young plants now available are strikingly different and robust in both leaf and stalk.

Another plant getting some buzz in 2007 is a breakthrough begonia named Bonfire. Developed in a breeding program in New Zealand, it derives from a species named Begonia boliviensis collected in the mountains of northern Argentina and is distinguished by its orange-red, tongue-like blossoms that are so abundant that they cover up to half of the entire bush. Whether this is a good begonia for Washington remains to be seen, but it is a spectacular plant when happy and seems worth a try. Bonfire has been introduced to the United States by Anthony Tesselaar Plants and is available in the area at Homestead Gardens, said Sally Ferguson, a spokeswoman for Tesselaar.

Don Riddle, president of Homestead, said he also is struck by the first double-flowered calibrachoa named Double Pink, as well as a petunia named Raspberry Blast that is self-cleaning and freely branching, meaning you won't have to remove faded blooms to keep it flowering.

Don't limit your plant adventures this year just to annuals, however. Tender and hardy salvias continue to be important plants, both set in containers and integrated into garden beds. Heatwave is the name of a series of four Salvia gregii varieties, perennials introduced by Monrovia and bred for their long flowering and heat and drought tolerance. They are named Blaze, Flare, Sizzle and Scorcher.

Salvia Sensation Rose is also a new hardy salvia, bred to be compact and useful for containers and for front of the border.

Recent introductions, while not new this year, are still to be commended. The wispy, white-flowering Diamond Frost euphorbia is a great foil to plants with coarser texture. And, as Riddle points out, the Dragon Wings begonia "is a phenomenal plant" with dark-green glossy leaves and pendent red blossoms.

I also like ground-hugging sedum, or stonecrop, which takes the heat and dryness of summer. Look for a variety named Lidakense, which has blue-gray succulent leaves, tinged purple. It has starry pink flowering in midsummer, but the foliage is so pretty the flowers are merely icing. Look for it at Johnson's Florist and Garden Center in Olney.

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