Geraniums offer startling array of vivid, colorful varieties

This week I received a letter from a Surry reader that makes for an excellent winter gardening topic: geraniums.

I can hear a few of you letting out a moan, but wait! Certainly, there are those among us who would just as soon never set eyes on a geranium again, but judging by the percentage of greenhouse space and overall industry production of the potted gems, geraniums definitely land on the list of favorites.

Over the past 15 or so years, plant-breeding programs have produced a great selection of geranium

varieties, not all of them indoor-pot dwelling. Some are actually hardy garden perennials. If you’re not interested in indoor cultivation, you may still enjoy the beauty of these lush flowering plants.

Our indoor gardener’s letter reads, “I had a gorgeous crop of geraniums in window boxes, which I purchased from a local nursery. Thinking I would save them over the winter, and save the cost of new ones, I left them in our garage just ONE night too long this fall and lost them all to the cold.

“I would love to be able to start a bunch from seed, but notice in the Burpee catalog that 10 tiny seeds cost $4.95, and the instructions from their consultant are to plant two in a peat pot and discard the weaker before transplanting the one remaining to a larger pot. At that, it might not make it in an ordinary dining room-window setting. So it could get pretty expensive and I would have to buy plants anyway in May or June.

“I’m trying to decide what to do. Have you or other kitchen windowsill gardeners had any success with starting geraniums from seed?”

Most likely this reader’s geranium was a hybridized member of the genus Pelargonium. Pelargonium geraniums fall into four main groups: the ivy-leaved, the scented-leaved, the zonals and the regals. Ivy-leaved geraniums have trailing evergreen leaves that are stiff and generally waxy in appearance. These gorgeous plants are a bit harder to grow than the popular zonals, but their show and depth of floral color are worth it. A range of deep red, pink, mauve, purple and white flowers is available in dozens of single- or double-flowered varieties.

Regal geraniums – also commonly called Martha Washington geraniums – are generally bushy with short, jointed stems. The midgreen leaves are rounded or sometimes lobed or toothed. Most Martha Washington cultivars produce clusters of single flowers.

Zonal geraniums have a tendency toward upright growth, and have rounded leaves that often show a darkened strip or “zone” about their midsection. Leaves of the zonal geranium may be bicolored or multicolored, with inner “zones” of dark green, bronze or maroon.

Dozens of varieties of zonal geraniums offer the gardener an enormous range of color from traditional whites, reds and pinks, to shocking violets, deep purples and bicolor single, semidouble and double flowers.

Some geraniums grown in commercial greenhouses today are grown from seed. These tend to be single-flowered hybrids. A vast number of geraniums are grown from vegetative cuttings. This tends to be the mode of propagation for the larger-flowered cultivars.

Most geraniums sold in Maine are treated as annuals although, botanically speaking, they are perennials. Most members of the genus Pelargonium are hardy to just above freezing. Scented-leaved types are typically hardier than the rest; with great effort and added protection of a south-facing wall, layers of mulch and the blessing of a mild winter, some may overwinter in Zone 6.

It certainly is possible to propagate geraniums from seed. So, to answer our Surry reader’s question, by all means, don’t hesitate to try your hand at starting geraniums from seed. Start by purchasing seed from a reputable dealer and try to match the variety you select to the environment you’re able to provide. For example, if you are concerned that your home may be a bit deficient when it comes to lighting, try to get a recommendation for a variety that will do well in indirect light. Sow seed in a potting medium and maintain temperatures between 55 and 64 degrees F. Late winter or early spring is a prime time to put the seeds to soil.

A more expedient and less time-consuming mode of propagation for any pot-dwelling geranium is through vegetative cutting. A simple technique is to take soft cuttings (relatively new growth) at any time and place each cutting in a glass jar filled with water.

Most geraniums will root in a couple of weeks and can then be placed in damp potting soil. Alternatively, fresh cuttings may be rooted directly into a potting medium, so long as soil moisture is maintained during root development.

Not all geraniums are grown indoors. True geraniums – members of the botanical genus Geranium – are garden gems. Like the Pelargoniums, they belong to the family Geraniaceae, yet they have distinctly different qualities and attraction to the gardener. Next week I’ll share some of my favorites.

Diana George Chapin is the NEWS garden columnist. Send horticulture questions to Gardening Questions, RR1, Box 2120, Montville 04941, or e-mail them to dianagc@ctel.net. Selected questions will be answered in future columns. Include name, address and telephone number.