In actuality, scented geraniums are not geraniums at all, though they share the same family name with hardy geraniums: Geraniaceae. Here, I’ll stick with common parlance and call them scented geraniums, rather than pelargoniums.
Scented geraniums are tender perennials that may live through a mild winter in a Zone 7 garden, but why take that chance? If you get freezing temperatures, overwinter your plants indoors. Scenteds will grow best overwintered on an unheated porch where temperatures are in the 50s.
Once indoors, scented geraniums need as much light as you can give them, preferably direct sun. They may grow a bit spindly over the winter, but you can prune or take cuttings in the spring, once growth picks up. Be careful about overwatering – too much water means death to these plants. Water when dry, not before.
In the great outdoors, scented geraniums love sun, but not during the sun’s apex, and definitely not in a hot climate. There you’ll need to keep the plants shaded from direct midday sun.
Geraniums are often described as “carefree,” but that term is relative, and depends on your climate. Their greatest enemies are fungus and rot, a problem in steamy climates but not dry ones. To improve your chances of success, give scented geraniums well-drained soil. Potted specimens will appreciate a soilless mix, and in-ground plantings do best with some sand mixed into the soil. Set plants in a raised bed or mound to keep water from pooling around the roots.
Scented geraniums are great container plants and are striking grown as topiaries. One compelling reason to grow scenteds in beds, however, is that some grow to be large and shrubby and could easily overwhelm a container. Whether they’re grown in beds or pots, cut them back when they get leggy.
Cuttings can be rooted to start new plants. Indeed, the majority of them are propagated from cuttings, and only a few varieties (Apple and Coconut) come true from seed. Cut a stem 2 to 4 inches long just below a node, and place it in a pot filled with a soilless mix.
Although the flowers of scented geraniums are not the plant’s raison d’etre, they often provide a nice, quiet show. These plants are really grown for the leaves. There’s quite a variety of leaf sizes and shapes, some with deeply indented lobes, some softly rounded. There’s also a nice range in color and variegation, with pale yellows, chartreuse, and deep greens.
Appearance is one thing, smell and touch another. That’s where these lovely plants appeal to plantsmen and plain folk alike. The leaves have glands that contain complex volatile oils responsible for the heavenly scents released when you brush against them. Once you’ve smelled that perfume, you cannot resist reaching out and gently rubbing the leaves between forefinger and thumb, breathing in the scent the plant so generously offers.
You can find numerous varieties of scented geraniums in mail order catalogues. One is the common and easily found Peppermint. Not only does it have a great fresh scent, but it also has large, downy leaves and white flowers. Galway Star is fairly new. Its rounded leaves are edged in a creamy white, and its scent is lemon. Charity has deeply lobed, variegated leaves of a deep green and chartreuse, which emit a lemon-rose scent.