I have never cared for impatiens, and I suspect I’m not alone among Pacific Horticulture readers who are bored by the ubiquitous columns of impatiens marching up either side of the walk to the front door of far too many houses. What we tend to forget, however, is that lack of creativity in the use of impatiens is a world apart from the wildly diverse nature of the genus itself.
Derick Pitman opened up that world for Pacific Horticulture readers with his two-part series on the “other” impatiens (see October 2006 and April 2007). Now, Raymond Morgan’s book further explores that diversity, which runs to more than 1,000 species, relatively few of which have been introduced into the nursery trade. As he points out, Impatiens walleriana (the ones marching to the front door), along with the New Guinea hybrids (I. hawkeri group), and, to a lesser extent, I. balsamina and I. glandulifera, are generally the only species widely cultivated, although extensive hybridizing, especially of the first two, has given us hundreds of cultivars.
Morgan discusses those cultivars and moves on to breeding programs with less well-known species that have recently given us so many new colors and flower forms, including the Seashell series, the Fusion series, the Butterfly series, and the Gem series. He also focuses on more than 200 species from around the world, organizing his review according to their primary geographic ranges: Africa; Madagascar, the Comoro Islands and the Seychelles; the Himalayas; Southern India and Sri Lanka; and Southeast Asia. Augmenting his descriptions are over 160 color photographs that will set any plant lover drooling.
Though primarily from tropical and sub-tropical areas, impatiens are mostly plants of montane communities, preferring those cooler temperatures in damp, shady, woodland habitats. For example, the commonly grown busy Lizzie (I. walleriana), is a summer-flowering species from the mountains of East Africa, flowering abundantly in our gardens from May till first frost; although a perennial, it is most often grown as an annual.
Impatiens flowers, rivaling those of orchids in their variety, fall into two main groups. The flat-faced shape, typified by busy Lizzie, is pollinated by butterflies and moths; the other, an elongated cup that looks like an inverted British policeman’s helmet, is pollinated by bees and wasps.
In terms of growth habit, variety rules. Ground covers, trailing types, and erect shrubs more than nine feet high are some of the forms the genus can take. There are semi-aquatic species, as well as epiphytes, lithophytes, and even caudiciform succulents. The bizarre Impatiens mirabilis from Thailand is an example of the latter, growing to be a small tree roughly ten feet high with a diameter of almost twenty feet—certainly not your grandmother’s busy Lizzie!
Morgan does not just tantalize with unavailable species. He also provides solid advice on propagating, growing, treating the few diseases or pests they might fall prey to, and landscaping with these versatile plants. From the herbaceous border to the patio, from houseplant to hanging basket, impatiens make an impact. He even tells how to make a busy Lizzie flower ball, which resembles a tree standard, by wiring two hanging baskets together and supporting them on a stout post hammered into the ground.
Where does the name Impatiens come from? From the explosive nature of the seed capsule, which ejects its seed at the slightest touch, thus giving rise to another of its common names, “touch-me-not.”
Despite the latter name, after reading Morgan’s book, I suddenly would like to get my hands on a whole lot of different Impatiens.
Jill Vig, horticulturist