Geraniums And Impostors

Back in my youth, when I knew nothing about plants, a geranium was a geranium. Every May, the local churches would have their annual geranium sales, and every Mother’s Day we gave our mothers geraniums. Life was good and life was simple. But then I discovered ivy geraniums, then specialty geraniums like the Regals and Martha Washington and all the fancy-leaved varieties. Oh, but there was more. There were the bi-colored, tri-colored geraniums and dozens of scented geraniums including the ones touted to repel mosquitoes.The one thing that all these geraniums have in common, though, is that they are all impostors and not really geraniums at all. All these plants fall into the plant genus pelargonium or the storksbills. In this case geranium is just a common name based on the much larger family geraniaceae. Remember your high school biology?

Now, if you go into the perennial section of your favorite garden center and if the perennials are arranged alphabetically, you’ll find … geraniums. Ah, but these are the true geraniums, not the pretenders, and these are often referred to as the cranesbills. You can find varieties like birch’s double, johnson’s blue, and maybe a dozen others including the exquisite ground-covering Rozanne, which was introduced in 2008 and has become wildly popular.

And speaking of wild, we also have our wild and native geraniums. One that can be quite weedy is Geranium robertianum, or Herb Robert, which produces small pinkish flowers and can show up anywhere on the property, and which self-seeds but is easily removed simply by pulling before it seeds. The scent given off by its crushed leaves has been likened to the aroma of burning tires. In the woods, though, you may find a native wildflower that’s a wild geranium known as Geranium maculatum, or the spotted geranium, with its purplish pink flowers that occur in May.

Most of the pelargonium-type geraniums sold these days are sold in pots that are 4 inches in diameter and larger. The basic colors are red, white and pink, but they can also be found in lavender, purple and magenta. The flowers can be plain or fancy, but the stems of the plants are generally thick, with the foliage being green or “zonal,” showing some banding of darker and lighter colors. These plants are tender and don’t tolerate cold soils or cold temperatures, but they do well in the sun to slight shade and are popular in window boxes and planters. The plants can grow as tall as 4 feet, but at that point they often need staking.

Most of these are heavy feeders, so regular fertilization or mixing a time-release fertilizer in the soil will result in vigorous flowering plants. Most varieties will also benefit from fading flowers being removed, as this encourages new buds to be developed, and if the plants are lightly pruned in early summer this can encourage blooming well into October. However, when you prune, do it lightly, because continued blooming will depend on not removing stems that are already budded. The foliage and flowers don’t appreciate being wet, so overhead irrigation or watering from above with a can will create problems. Try to water by getting the moisture into the pot while keeping the foliage dry.

While most varieties of pelargoniums are patented, you won’t get arrested if you want to try to carry a plant from one year to the next by taking cuttings. This is done in late summer or very early fall, and the cuttings are fairly easy to root. The rooted cuttings are carried through the winter indoors, then late in the winter new cuttings are taken and rooted for the summer garden. Ivy or hanging geraniums are handled in the same manner, and I always liked the Balcon series when I had an apartment with window boxes over Montauk Highway. Ivies also are great in hanging baskets, which is their primary use, but as the plants get larger keeping them watered in small hanging baskets can be challenging. These pelargoniums also benefit from occasional pruning to encourage later blooming, but cuttings don’t ever winter as well as the standard varieties do.

Still within the pelargoniums are the fancy varieties that have more exotic flowers and foliage like the Regals and Martha Washington, but there are smaller types that have attractive foliage like the bi-colors and tri-colors that are grown more for their decorative foliage than their flowers.

Lastly there are the scented pelargoniums. These are also tender plants, but if you want to grow a scented garden or have scented potted plants on your patio or deck these can be really nice to use. Most are sold by specialty growers that you can find online, but you may be able to find some scented geraniums at local garden centers as well. There is one scented geranium often sold as the citrosa geranium that is purported to repel mosquitoes. There is no scientific evidence to support this claim, but it has some repellency within several inches of the plant, no more.

As for the true geraniums, the perennial ones, I think there’s one for every garden. There are about 50 varieties available; the flowers are much smaller than the ones on the pelargoniums, and the form is different as well. Unless you are using a geranium like birch’s double, the flowers tend to be somewhat flat in dark pinks, lavenders, chartreuse and near blue and white. Some flowers have tiny dark stripes that radiate around the flowers, and the flowers can be borne either on short stems or wiry stalks above the plants. There are varieties that do well in semi-shade and some that do well in rock gardens, like Geranium cinereum Ballerina, which is about a half foot in diameter with short-stemmed flowers. My favorite in this group is Geranium cr. Laurence Flatman. I found this plant when I met, of all people, Larry Flatman, who was the perennial manager at Blooms of England. His namesake is a bit more vigorous and has brighter flowers than Ballerina.

Some of the varieties of perennial geraniums can be a bit tall and if not properly used they can literally fall over and look sloppy. I find this to be true of johnson’s blue, but when planted among other perennials they tend to support the plant, whose flowers are outstanding.

My classic English island border, inspired by the Blooms, has a geranium area about 20 feet long and ranges from 5 to 8 feet deep. In this lightly shaded area the geraniums cover the ground from a few inches up to 6 inches; with columbines, heucheras, tiarellas and astilbe occupying the next height level to about 2 feet; then, high above these, the summer-flowering Oriental and Asiatic lilies. The geraniums begin to flower in mid- to late May, with varieties like Rozanne blooming continuously from May through late October and supplying constant color as an underplanting.

So now that we’re all straightened out, you’ve got lots of options, from sun-loving pelargoniums to lots of scents, plants that hang, natives, herbals and some really great perennials. Keep growing.