Trowel & Error

The humble geranium

There’s more to this standby than meets the eye

By Nancy Crowe

Geraniums are among the most popular and reliable plants for home gardens. You can find them in any garden shop every spring, and their color will stick around pretty much until frost.

Geraniums like full sun, and they’ll grow in almost any type of soil. The plants should be set in the ground no deeper than they were in the pot — otherwise, stem rot is likely to kill them. In fact, the Ohio State University Extension advises planting the geranium more shallowly than it was in the pot. They’re heavy feeders, meaning you need to fertilize regularly to keep them happy.

A friend of mine had her geraniums, both potted and planted, drop leaves for no apparent reason. She blamed the soil in her brand-new subdivision (a legitimate concern), but it sounded more like bacterial blight. Unfortunately, there isn’t much you can do for that except remove the diseased plants (and, as always, refrain from getting discouraged).

During the winter, geraniums can be carried over as actively growing plants indoors. One way to do this is by taking cuttings and rooting them in sand, vermiculite or a good potting mix. Raise it as a houseplant and by spring, it should be ready to harden off and plant outdoors. The plants can also be lifted from the garden, potted and brought indoors. Yet another option is to dig the geraniums out, carefully shake the soil from the roots and hang them upside down in a cool, dark place. (That is, a cool, dark place you’ll remember in the spring.) Details on all of these methods can be found in the Purdue publication HO-85: Winter Storage of Geranium, Canna, Gladiolus, Caladium and Begonia, available at www.hort.purdue.edu/ext/HO-085.pdf.

What we know as geraniums are botanically known as pelargonium and thought to originate in South Africa, but they’re far from homogenous. Common or zonal geraniums are your basic bedding plants, with leaves that may have dark bands or silver/white markings. Their flowers may be single or double and are clustered into the characteristic round heads; red, pink, salmon or white are commonly seen.

The Martha Washington geranium is often sold as a flowering gift plant, but its lack of heat tolerance makes it a poor bedding plant. Ivy-leaved geraniums are the trailing counterparts of their common cousins and look great in window boxes and hanging baskets.

The scented geranium is a horse of a different color. These geraniums have leaves that, when rubbed or brushed, release scents of rose, lemon, nutmeg, apple, peppermint and whatever growers might think of next. Geranium essential oil, in particular rose geranium oil, is used as a flavoring, in soaps and
perfumes and for medicinal purposes. The scented geranium was named Herb of the Year for 2006 by the International Herb Association. I didn’t know there was an International Herb Association, but can you imagine their chapter potlucks?

Nancy Crowe

Master Gardener Nancy Crowe's Garden Spot column also appears in interactive format online.

Posted Wed, 11/21/2012 - 1:42 pm