Eric’s Pet Plant: Geraniums – Pelargonium species
I think he’s getting cabin fever over there in the snows at Yale, and that fed-up-with-winteritis is turning his thoughts to approachable old friends. On the other hand, after two serious touch-me-nots ( Tree Ferns and Cholla cactus) he may simply be thinking “approachable” as in “can be handled without injury.”
Geraniums – Pelargonium species
By Eric Larson
Pelargoniums or more commonly Geraniums were first known to be cultivated sometime in the late 16th Century, when a sample was brought to the botanical garden in Leiden from South Africa. (Most all species of Pelargonium are from southern Africa.) Some thirty years later the plant was introduced to England by John Tradescant the elder. Since then, their popularity has remained high, as a bedding plant, an herbal essence, for hanging pots and as focal points.
There are around two hundred species in the genus Pelargonium, which belongs to the Geranium family, Geraniaceae. This confusion of names stems from the fact that Linnaeus (1707-1778) correctly lumped true Geraniums with Pelargoniums in the same family, but incorrectly lumped them into the same genus. They didn’t stay lumped for long, at least botanically; French botanist Charles L’Héritier divided the plants into separate genera in 1789.
The genus name Pelargonium derives from the Greek word pelargos, for stork, because the flower looks like a stork’s beak. The genus name Geranium also derives from the Greek for the same reason, but from géranos, for crane. The true geraniums are called Cranesbills in common parlance.
There are a large number of wild species of Pelargonium, but within the horticultural world divisions are both simpler and more complex at the same time. Although gardeners need deal with only six major groups of Pelargoniums, each of these groups comprises countless hybrids and cultivars. The six groups are Angel, Ivy-leaved, Regal, Shrubby-leaved, Unique and Zonal.
The Zonal is the most commonly grown in this country, with slightly pubescent (a botanical adjective for ‘having fine hair’) leaves that show a zonal color variation. These are grown for their flower or leaf coloration, and are often used in beds or pots and grown as annuals. They are by and large descendants of Pelargonium zonale and P. inquinans.
Ivy-leaved Pelargoniums (by the way, I do not use the commonly accepted Latin plural for words ending in –um, when describing plants by genus and species. Not sure if I am conventional or iconoclastic in this practice, but frankly I don’t care) are used for hanging baskets, are often treated as annuals and are descended mostly from P. peltatum.
P. graveolens is the parent plant of the Scented-leafed Pelargoniums, which some folks put in the Unique category. P. graveolens is used in the perfume industry, and is grown and distilled for its aromatic qualities. While there are a number of different flavors of scented-leaf Pelargoniums, from citrus to mint to other fruits, the rose scented ones are most often used.
(We notice Eric isn’t identifying that last one as an Angel. It appears to have the requisite single, 5 petaled flowers with dark blotches and zone-free, crinkled leaves, but I’m not a big pelargonium fan so if HE isn’t saying for sure I’m certainly not going to.)
GROWING (PELARGONIUM) GERANIUMS
Pelargoniums are easy to grow, tolerant of heat, sunlight and drought, reflecting their nativity. It’s best to grow them in clay pots with a good well-drained soil mix because they hate wet feet – there are several root rots that can attack. Constantly damp soil is the most common cause of failure. Again, let’s blame it on their nativity.
A handful of insects can also cause problems, especially indoors. Over-wintering Pelargoniums often suffer from difficulties that would be of no concern if they were growing outdoors. Overall, however, pelargoniums are easy to grow and also easy to aquire, found in most garden centers, specialty nurseries, on-line and your dowager Aunt Mildred’s house.
I mention that last source because they propagate from cuttings quite easily, so a quick clip of the secateurs when Auntie is pouring the tea and you will have a clone of her fabulous black-leaved pink double-flowered pride and joy.
As a matter of fact, that act is quite déclassé, if not illegal in parts of Great Britain where horticulture rules. It is accepted practice to ask for cuttings first: most gardeners are happy to share, but please allow Aunt Mildred to bestow her largesse upon you in her own way.
Disclaimer: The opinions and views expressed herein are the sole responsibility of the author. Yale University and Marsh Botanical Garden and Leslie Land are not responsible for the iconoclastic viewpoint or less-than-successful humor attempted in these columns.