Some snooty gardeners yawn at the sight, or even the mention, of bedding impatiens, so ubiquitous these plants have become. But one does not always represent the whole, and so it is with the genus Impatiens. Most of the 1,000 species in this genus are native to the highland tropics of Africa, Madagascar, India, and most parts of China and Southeast Asia. They include plants so marvelous and new to the gardening scene you would never guess they are impatiens. And while the common bedding types are not known for hardiness, but there are some up-and-coming species that will return year after year in gardens as cold as USDA Zone 5.
ANNUALS AND TENDER PERENNIALS
In the 1970s, the USDA introduced I. hawkeri, or the New Guinea impatiens that have become so popular. Always eyecatching with their large blooms and whorls of green or variegated leaves, these have never really been good garden plants. Happily, hybridizers have recently begun crossing I. hawkeri with other species that are more adaptable to the garden. The results are the new Fanfare and Sunpatiens series. Both remain close to the species in flower shape and color, only differing in growth habit. Fanfare impatiens trail, excelling in hanging baskets; Sunpatiens are huge, reaching almost three feet tall. Both have sailed though garden trials, standing up to full sun and heat without blinking.
As recognizable as the New Guinea hybrids is Impatiens walleriana; it flows though flowerbeds in a confetti of colors, always looking superb. Different from this norm is I. auricoma, with its cup-shaped yellow flowers. A newer improved version, I. auricoma ‘Jungle Gold’, has a strength its parent lacks and resembles the multicolored ‘African Orchid’ hybrid. All these balsams (as impatiens are also called) grow to about two feet tall and can take a little more heat and humidity then most species.
Crossing I. walleriana and I. auricoma has led to more unique hybrids. Most notable are the Seashell series and the Fusion hybrids that recently replaced them. Fusion ‘Glow’ is the most interesting of the bunch, with its larger yellow flowers with two strong central blush spots.
Many of the new introductions are not hardy plants, but they do make first-rate annuals for beds or containers. One of the most exciting is I. niamniamensis ‘African Queen’, commonly called the Congo cockatoo. It covers itself head to toe with delicious-looking candy corn–colored flowers. If candy corn is not your taste, you can find cultivars in pink, bloody red, and yellow. More unusual are I. cecili and I. stuhlmannii, which brim with large pink oncidium-like blooms that would make any orchid lover swoon in desire. Silver variegated leaves make I. mackeyana sub. claeri, a four-feet-tall shrub from West Africa, stunning even out of bloom.
On the smaller side are I. nana, covered in deep magenta blooms, and I. telekii, whose little pink flowers remind one of little dancers with their arms thrown up in the air. These plants make up for their small stature with a good solid flower punch. Meanwhile, the many forms of I. sodenii tower over these munchkins. This monster looks like I. walleriana on steroids. Normally available in pale lavender, new flower selections are appearing with all-white flowers or white flowers with bright magenta markings radiating from their centers. Some of these cultivars offer flowers four inches across.
These tender perennials all come from Africa, but the piece de resistance hails from Tibet. From deep with in the Namcha Barwa canyon has come I. namchabarwensis, the first truly blue balsam in cultivation. Though it is rather tender, it does produce abundant seed and it can easily be grown as an annual.
The cold-hardy species of Impatiens are almost completely unknown to gardeners. Most originate in Asia. I consider the tough I. arguta, with its large lavender-blue or white flowers, the best. This remarkable species can easily take the heat of most areas of the United States and it is cold-hardy to Zone 7. With further testing, it may turn out to be even hardier. The sunny yellow I. stenantha looks different than most; its spurs curl above its petals instead of below them. This balsam makes an outstanding mounding perennial with gorgeous bronze-colored leaves that make the bright flowers shine. As for a groundcover, I. mengtzeana fits the bill first-rate, happily weaving its way though neighbors and over walls showing off it orange or apricot hued blooms in the fall.
A group of closely related species from Sichuan creep through the soil on stoleniferous roots. Impatiens omeiana ‘Eco Hardy’ and its other form, ‘Ice Storm’, have beautiful patterned leaves of yellow or silver. It is hardy to Zone 6. Another recent introduction, I. ‘Sichuan Gold’, has shown to be hardy in Zone 5 gardens. These three plants have similar yellow flowers, but the shrubby I. oxyanthera ‘Milo’ offers fascinating shell pink flowers with curious horns on the upper petals, as well as fuzzy leaves.
The tuberous I. tinctoria, which comes from Africa, can stand eight feet tall. It gives a wealth of large white flowers, orchidlike in looks and gardenia-like in scent. It dies back to its tubers in fall, like a dahlia; it is reliable in Zone 8 and can likely survive colder with protection. Its kissing cousin, the pink-flowered I. flanaganae, is decidedly deciduous and may prove to be just as hardy. The prolific burgundy tubers of this species will misshape a plastic container by the end of the season.
There’s no denying that impatiens offer bountiful, fanciful blooms and bright colors, and the bedding sort has become intrinsic to the garden scheme. Love those or hate them, take a look at their less common cousins. They show enormous potential and deserve a chance to enter the scene, too.