Like your best pals, geraniums are cheerful, easygoing, and non-temperamental. They let you enjoy their company without making outrageous demands. Like true friends, they hang in there, even if you neglect them.
Many geraniums bear showy flowers. Some flaunt exceptionally colorful foliage. And the leaves of scented types delight our noses with aromas of lemon, mint, and rose.
Geraniums are also very versatile plants. Most kinds look good in pots. Cascading types, like ivy geraniums, are especially attractive trailing from hanging baskets and window boxes. Scented geraniums make fine summer guests in herb gardens.
Before we go any further, let's clear up the botanical confusion. The plants we're discussing here are properly called pelargoniums. When Dutch and English explorers came across these plants in South Africa in the 1700s and introduced them to Europe, botanists originally classified them as geraniums. Later, they were moved to the genus Pelargonium. But to most of us, they will always be geraniums.
Here's an overview of the major types you'll find at nurseries.
Common or zonal geraniums
Zonal types, with round leaves topped by umbrella-shaped flowerheads, are the plants most commonly thought of as geraniums. "Zonal" refers to a zone or ring of deeper color just inside the leaf margin (the zone isn't always conspicuous).
There are single-flowering types, but doubles are the big sellers. Colors include red, magenta, salmon, orange, pink, lavender, and white; some flowers have a second color.
A subgroup of zonals, called fancy-leafed geraniums, are grown primarily for their variegated leaves. A good example is 'Mr. Henry Cox', which has yellow leaves with a red zone and splashes of green and purple-brown.
Standard zonals like full sun; variegated fancy-leafed types do best in partial shade. Use them as bedding plants or grow them in pots.
Their succulent, glossy leaves resemble those of ivy. They produce single or double flowers in a range of colors - red, pink, lavender, white, and bicolors - over an extended period. Because of their trailing habit, floriferous nature, and tolerance of tough conditions, ivy geraniums are one of the most popular summer annuals for containers. The Balcon series is particularly carefree - they're self-cleaning. In frost-free climates, ivy geraniums are also used as a ground cover. Ivy types normally perform best in full sun; in very hot climates, like the deserts, they appreciate afternoon shade.
This group is prized for the delightful fragrances its leaves release when brushed or rubbed. Rose, lemon, and mint are the predominant scents, but there are many more, including apple, coconut, ginger, nutmeg, and other herbal aromas. Leaves vary greatly in size and shape; some look more like leaves of oaks, grapes, or ferns than geraniums. Leaf textures can be coarse or smooth as velvet. White or soft yellow variegation is common; a few kinds have brown splotches.
All scented types are attractive in containers, but the trailing kinds like chocolate mint, peppermint, and 'Snowflake Rose' are ideal in hanging baskets or window boxes.
In frost-free climates, pelargoniums make great landscaping plants. Try apple or nutmeg as edgers, advises Kathryn Jennings of Katie's Scenteds, a geranium specialist in Lakewood, California.
Most scented types look their best when given some shade "at least in the afternoon, and especially in hot climates," says Jennings.
These are grown for their flowers. Regal geraniums (also known as Martha Washington geraniums or Lady Washington pelargoniums) are big, shrubby plants with stiff dark green leaves and showy 2- to 3-inch-wide blooms in rounded clusters. Colors include red, orange, pink, purple, mauve, and white. Most have darker markings of some sort, sometimes in dramatic, near-black shades. The regals have a shorter bloom period than ivy and zonal types, but hybridizers are working on that. In the meantime, try longer-blooming 'Georgia Peach' or 'White Champion', says Jack Tipich, a San Pedro hobbyist known for his prizewinning regals. Regals love sun, and they're usually grown in pots.
Geraniuim growing tips
SOIL. Geraniums tolerate most garden soils, as long as they provide good drainage. If your soil is particularly heavy, amend it with compost or pumice. To improve the drainage of potting soil, mix in some additional perlite.
WATER. Irrigate bedding plants when the top inch of the soil is dry. Water container plants when the soil surface is dry to the touch. Regals are a little thirstier; irrigate whenever soil approaches dryness.
FERTILIZER. Add a balanced slow-release fertilizer to the potting soil or bed area at planting time. Then supplement periodically with a liquid fertilizer at half or quarter strength.
PESTS AND DISEASES. As a group, geraniums are fairly trouble-free. Ivy geraniums have virtually no pest problems or diseases wherever they are grown. The same is true of scented types in most areas.
Rust can be a problem with zonal types. If it occurs, pick off afflicted leaves or spray with a fungicide labeled for rust control.
Various budworms are an annoyance in mild-winter areas. They nibble holes in leaves and drill into flower buds, spoiling the blooms. Their favorite targets are zonal and scented types with soft leaves. At the first sign of damage, spray with Bacillus thuringiensis (BT). Repeat every seven days until the problem dissipates. Or grow ivy or scented types that aren't bothered by budworms.
For unusual scented, fancy-leaf zonals, and other geraniums rarely found in nurseries, try these mail-order sources.
Geraniaceae. (415) 461-4168 or www.geraniaceae.com.
Goodwin Creek Gardens. (800) 846-7359 or www.goodwincreekgardens.com.
Katie's Scenteds. (562) 619-6266 or www.katiesscenteds.com.