DIY: Hybridizing Scented Pelargoniums
Scented geraniums are admirable in so many ways. We can step back and view them within the intricate tapestry of a garden or move forward to explore the smaller secrets held in their elemental fragrances, shapes, colors, and textures. Unlike most garden plants, their fragrances come not from transitory blossoms but may be summoned from the leaves any day of the year (or appreciated in potpourris, cosmetics, and bouquets). Some varieties also have a place in the kitchen, flavoring jellies and cakes.
Popularly known as scented geraniums, these plants are actually scented pelargoniums. Like the common garden geraniums, they belong to the genus Pelargonium. The generic name, from the Greek pelargos, “stork”, comes from the notion that the long, narrow seed capsule resembled a stork’s bill. Storksbill is also an old common name. Pelargoniums belong to the geranium family (Geraniaceae), as does the genus Geranium, which includes cranesbills and herb Robert.
There are some 250 naturally occurring species of Pelargonium, most native to South Africa. Many have highly scented leaves, which are a natural deterrent against grazing animals, but only a few are the scented pelargoniums of gardens. The ease of hybridization, which has led growers to develop countless cultivars of scenteds, has resulted in nursery plant lists of more than 100 scented varieties, but only a few of these are true species. Among the best known of these are Apple (P. odoratissimum), Coconut (P. grossularioides), lemon (P. crispum and P. citronellum), rose (P. graveolens and P. capitatum), and the refreshing Peppermint (P. tomentosum).
The scent is contained in small beads of oil produced in glands at the base of tiny leaf hairs. Bruising or crushing a leaf breaks the beads and releases their fragrance. A few varieties need but a casual brushing to produce a noticeable fragrance. Some have an easily identifiable fragrance, such as lemon, peppermint, orange, or rose, whereas others may smell like cinnamon to one person and citrus to someone else. Others have only a green-leaf scent.
The leaves of scented pelargoniums vary in shape, size, color, and texture. They range in length from 1/2 inch to more than 6 inches. Some are almost circular, others lobed to varying degrees; still others are as finely divided as a fern frond. The most common leaf color is medium green, but leaves may also be deeper green or even grayish or silvery in tone. Some leaves are splashed or edged with white, cream, or yellow. Purplish brown may blotch leaf centers or color their veins and midribs. Leaf textures can be smooth, rough and raspy, hairy, or soft and velvety.
Though scented pelargoniums are grown mainly for their fragrant foliage, the flowers, which are produced heavily in spring, then intermittently throughout the growing season, are often attractive as well. Unlike those of many of the common garden geraniums, the blooms of scenteds don’t overshadow the beauty of the leaves, but rather emphasize it with soft contrast. The petals range in size from a scant 1/8 inch up to 1 inch long; they are most commonly white, rose, or lavender, less commonly salmon or red. The flowers are almost always single, with the upper two petals widely separated from the lower three. The upper petals are usually wider and often stippled with deep purple or reddish markings.
In their native South Africa, scented pelargoniums are perennial, living and flowering for several years. The species vary in habit from low, scrambling trailers to shrubs more than 6 feet high, and they are found in a multitude of habitats from the forest understory to the seashore. Because they cannot tolerate freezing temperatures, scented pelargoniums can be grown outdoors in North America only in frost-free regions. In cooler climates, they may be grown as annual bedding plants; they are especially appealing intermingled with other garden flowers. As useful as they are when planted in beds, though, scented pelargoniums often have their finest moments in containers. Pelargoniums and pots seem made for each other.
Scents In Pots; Outside and In
Containers offer many advantages in a landscape, chief of which is their portability. You can put them anywhere that you can carry them and care for them, and when you tire of the way they look, you can rearrange them. Scented pelargoniums can thus enhance any deck, patio, or gazebo; place pots so that the foliage is within easy reach of the chairs and benches.
We like to make mini-gardens of four or five different scented pelargoniums in half whiskey barrels, choosing varieties with contrasting fragrances and leaves. We might place a tall, upright type such as Lime, Charity, or P. crispum ‘Major’ at the back of the planter, with a medium-sized, bushy variety such as Fair Ellen or Concolor Lace in the center and shorter, trailing kinds such as Nutmeg, Apple, or Dean’s Delight in the foreground. One or two plants of each will make a bountiful display.
Many varieties are suitable for hanging baskets or window boxes. Sprawling Coconut, Apple, Lilian Pottinger, Old Spice, or Nutmeg may be mixed with trailing annuals such as verbena or portulaca, or with perennial herbs such as creeping thymes for a fuller effect.
Although scented pelargoniums in large pots can be an impressive garden feature, a collection of different varieties in small pots, neatly displayed on a bench or plant stand, can be equally captivating. A few plants trained into standards or espaliers can add a vertical element. Such a collection fairly invites you to stop and browse, and the small containers are easy to move indoors for the winter or whenever severe weather threatens.
Care and Feeding
Aside from buying one, the easiest way to get started with a scented pelargonium is to take cuttings from actively growing shoots of an established plant. Cut a stem 2 to 4 inches long just below a node, and stick it in a 2 1/2-inch clay or plastic pot filled with soilless potting mix (a rooting hormone is unnecessary). Choose a mix that contains peat moss, perlite, vermiculite, shredded bark, and/or washed sand, one that will hold moisture evenly but allow excess water to drain off rapidly—pelargoniums hate wet feet. Water them in well, and put them in a bright spot or under lights.
When the cuttings have filled the pots with roots, usually in about six weeks, transplant them, with the same potting mix, to larger pots, then again in a few more weeks into pots large enough to hold them at maturity, usually at least 8 inches wide by 8 inches deep. Scenteds grown in containers need repotting every year or two.
Water plants thoroughly when the top of the soil begins to dry out; empty out any water that collects in saucers placed under the pots. Overwatering promotes soil-borne diseases and weak, soft growth, whereas underwatered plants are typically short and slow growing and may have yellow, wilted leaves. Check plants daily until you have determined the proper watering schedule for each one. Be aware, though, that water requirements are likely to change with the seasons. Plants need less water in winter when light levels are low and growth has slowed.
Feed scented pelargoniums with a balanced water-soluble liquid or controlled-release granular fertilizer, such as 15-15-15 or 15-30-15, at half the manufacturer’s recommended dosage during the growing season and tapering off during the winter. A teaspoon of epsom salts added occasionally to a gallon of fertilizer/water mix will provide magnesium if your fertilizer does not provide it—check the label. Although we use organic fertilizers in the garden, we have yet to find one that works well for container-grown scented pelargoniums.
Outdoors, keep your pots in a bright spot but shielded from direct sunlight in hot climates. If the plants begin to get leggy, move them to a location where they will get more sun. Bring them indoors when frost threatens and place them in a sunny, south-facing window where they will receive four to five hours of sunlight daily or under lights. If you grow scenteds in beds, it is far easier to winter them over by rooting some cuttings in the early autumn than to dig up large plants, pot them, and bring them inside.
During the winter, inspect the plants regularly for pests and diseases and remove dead leaves promptly. Pests are seldom a problem for outdoor plants. Even indoors, scenteds are not particularly prone to diseases or pests if cared for properly. Aphids, whiteflies, and spider mites can usually be controlled by spraying affected plants with insecticidal soaps or horticultural oil.
Prune and shape scented pelargoniums when growth is leggy; the best time to prune established plants is in late winter or early spring after growth has resumed, but we do minor pruning all year.
Cultivars must be propagated by stem cuttings to ensure that their offspring are identical to the parent, but true species may be grown from seeds. Scented pelargonium seeds are seldom listed in mail-order catalogs, but you can collect them from your own plants; they are ready to harvest when the carpels turn brown and a dark line marks the style. (If you grow different kinds of scented pelargoniums in close proximity, you many find that the offspring of these seeds are not identical to the plants from which you collected them but are hybrids.)
• Faye Brawner Geraniums, Rt. 4, Box 525A, Buckhannon, WV 26201. Catalog $3.
• Goodwin Creek Gardens, PO box 83, Williams, OR 97544. Catalog $1.
• Logee’s Greenhouses, 141 North St., Danielson, CT 06239. Catalog $3 (refundable).
• Rasland Farm, Godwin, NC 28344-9712. Catalog $3.
• Well-Sweep Herb Farm, 317 Mt. Bethel Rd., Port Murray, NJ 07865. Catalog $2.
With his wife, Dotti, Jim Becker is co-owner of Goodwin Creek Gardens in Williams, Oregon, and coauthor of An Everlasting Garden (Interweave Press, 1994). He has been writing articles for The Herb Companion since 1989. Faye Brawner is a geranium collector and hybridizer and owner of Faye Brawner Geraniums, a nursery in Buckhannon, West Virginia. This article is adapted from Scented Geraniums, an Interweave Press book scheduled for release in May.