Impatiens, improved, poised for a comeback

Improved strains of impatiens are here. — devaburger/Creative Commons

Impatiens, once a staple of the summer garden, fell out of favor a few years back when downy mildew struck, turning beds of these obliging plants into a mass of wilted stems.

That was back in 2012. Since then, researchers and plant breeders have been hard at work and last year introduced new disease-resistant varieties that may win you back.

Syngenta Flowers has a new series called Imara XDR that’s highly resistant to downy mildew and PanAmerican Seed has weighed in with the Beacon line. Seeds are carried by major suppliers like Burpee and Park Seed, but you might be lucky enough to spot transplants at your local garden center.

These new cultivars may restore impatiens to their place as the top annual in America. At their peak, some 15 million flats valued at $250 million were sold each year. Why? Because they work. They buckle down as soon as they are set in the soil and labor prodigiously all summer long to produce reams of bright-eyed flowers.

Impatiens are uniquely adapted to shade, where it is often difficult to have color. The blossoms are self-cleaning, that is to say, drop off without the need for constant dead-heading (like the petunia).

They also are among the few plants that allow you to abandon careful consideration of color schemes, since all their many colors get along without fuss. Does the thought of pink and orange together make you shudder? Not with impatiens, where the effect is simply electric.

The impatiens we know today once had tenuous claim to a certain exalted place in the world. Originally, they were known as sultana, after the Sultan of Zanzibar, in whose island realm they were discovered — although there’s no evidence he favored them.

Actually, impatiens grow throughout eastern equatorial Africa, and were introduced to the Western world in 1896 by John Kirk, a naturalist who accompanied David Livingstone on many of his African expeditions. Their modern botanical name, Impatiens walleriana, honors the Rev. Horace Waller, a missionary to central Africa.

Jewelweed, the wild form of impatiens. — zen/Creative Commons

It wasn’t until these African species were crossed with Costa Rican relatives in 1943 by plant taxonomist Claude Hope that the modern impatiens began to emerge. And it was really only after World War II, when breeding in Europe and the New World produced good garden strains, that its popularity began to soar.

The sprawling family tree of Balsaminaecae has many branches worldwide with more than 1,000 species, and many of you may even know the North American native, jewelweed.

Growing in wet places, with the same hollow stems and hilariously small root system, jewelweed bears orange-yellow flowers and can reach a height of 4 or 5 feet. Its chief claim to fame is its sticky sap, which is said to counteract the effects of poison ivy (a handy thing, since the two often grow together).

Other familiar members of the clan are the annual known as balsam, a Victorian favorite with little rosebud flowers, and the New Guinea impatiens, discovered in Papua in 1970 by a team of American botanists and developed for the trade at Longwood Gardens in Pennsylvania.

SunPatiens, a cross between the common garden strain and New Guinea impatiens, were introduced about 10 years aqo. These are also disease-resistant but are generally sold as larger plants and are more expensive than the flats of seedlings gardeners were accustomed to buying.

What all of the impatiens have in common is a certain hasty impatience about propagating themselves. Their seed capsules are stuffed with tiny seeds — as many as 46,000 in a half-teaspoon — and when ripe, they burst explosively at the slightest touch, which is responsible for another of their names, touch-me-not. (Sterile hybrids do not necessarily follow suit.)

What this common flower offers the impatient gardener is fast results with a minimum of attention, and a season of bloom that lasts until frost. It’s a grand performance, and in the garden, that’s not really very common at all.