Geraniums 101
Cynthia Druckenbrod
When you think of geraniums, what comes to mind? Did you imagine a bright red or pink cluster of flowers perched atop a stalk that extends six inches or more above fuzzy, light green leaves? Geraniums have been a ubiquitous plant since Europeans began displaying them in gardens in the early seventeenth century. In Tuscany, red geraniums were often planted in borders or used as accent plants. In the US, it seems geraniums are enjoying a revival in the landscape as well as in container plantings.
Over 250 species of geraniums are known and they all originate from South Africa; is it any wonder that these plants like the bright light and semi-dry environment of a Mediterranean climate? Even with new hybrids debuting yearly, the uncomplicated red geranium continues to grace our gardens and containers. In window boxes, the red geranium stands out like no other plant.
There are actually several groups of geraniums. The scientific name, Pelargonium x hortorum, refers to the common, annual bedding and container geranium that is arguably one of the most popular plants sold in garden centers. While they are fairly easy to grow, keeping in mind the following suggestions will ensure healthy, happy geraniums. If they are planted too closely to each other (<10”), poor air circulation and increased moisture will lead to fungal, leaf and root diseases. They also require constant deadheading for summer long blooming. Feed them monthly with a good even-numbered fertilizer.
The ivy geranium (P. peltatum) is most often grown in hanging baskets and window boxes, where their long, trailing stems cascade up to four feet long. Flower color ranges from white to dark rose. They are profuse bloomers that attract one of my favorite insects, the hummingbird clearwing moth (Hemaris thysbe). The moths will hover over the blooms, sipping in the tiny droplets of nectar. Ivy geraniums grow best in partial shade. Varieties to consider include ‘Comtesse Degrey’, ‘Jeanne d’Arc’, and ‘Giant Lavender’.
Scented Pelargonium species will do quite well in container gardens. Their fuzzy leaves contain oil glands that, when touched, exude a variety of fragrances: rose, peppermint, lemon, pine, and many others. Regardless of the scent, all scented geraniums should have partial shade and well draining soil.
Finally, true, hardy geraniums (Geranium sp.) are generally grown as perennials. Unlike Pelargonium, geraniums do quite well in a woodland setting and behave like ground covers. Their flowers range in color from deep lavender to pinkish white and are just a few inches wide. There are only a few dozen species in cultivation; many are available through specialty perennial plant mail order catalogs.