Citrosa

Citrosa, aka scented "scented-leaved geraniums" refers to a group of species within the Pelargonium genus that have leaves that emit a fragrance when touched or lightly bruised. These plants are within the large group we generally know as "garden geraniums" or "annual geraniums," which also includes ivy geraniums, zonal geraniums, and Martha Washington geraniums.

Common name notwithstanding, it's important to note that this entire group is different than the various cranesbill geraniums, or "true geraniums"—the plants that have the rightful claim to the name Geranium. The plants we know as garden geraniums were once part of that genus, but after they were separated into their own Pelargonium genus in 1789, the use of the common name persisted, right up to this day.

Scented-leaved geraniums (Pelargonium spp.) have glands at the base of their leaf hairs where the scented oil is formed. Crushing the leaves—or in some cases merely touching them—releases the oil and the scent. However, the leaves of scented geraniums closely resemble those of other garden pelargoniums, so you can't always tell the type of geranium just by looking. These plants have many leaf shapes, from round to finely cut and lacy, and leaf colors from gray-green to lime green.

Most scented geraniums have relatively small flowers; some are quite lovely, and some are so tiny you will barely notice them. Each flower has five petals, two larger upper petals, and three smaller lower petals.

Note that some people can develop contact dermatitis from handling scented-leaf geraniums, and the plants are toxic to cats, dogs, and horses.

Scented-Leaved Geranium Care

Unlike most other types of pelargoniums, which are named for the color of their blooms, scented-leaf geraniums are typically named for their scent. There are dozens of varieties of these fragrant plants, but some of the most popular include chocolate, rose, cinnamon, mint, apple, and lemon. Although scented-leaved geraniums are technically tender perennials in USDA zones 10-11, they are most often grown as annuals.

To best enjoy their fragrance, plant scented geraniums where you will rub against them—along a walkway or at an entrance. These are great plants for containers, filling out and spilling over the edges. Scented geraniums are especially nice in individual pots, clustered together.

Pelargoniums are fairly carefree plants that don't require much in the way of watering and feeding, although potted plants should be monitored for soil moisture. In colder climates, potted specimens can be brought indoors to either sit dormant in a cool, dark area or placed in a sunny window to grow as a houseplant. Some people dig the plants up entirely, hang them bare-rooted in a cool dark place, and replant in the spring. Not every plant will survive this treatment, but a surprising number do.

Light

Like other garden pelargoniums, scented-leaved geraniums prefer full sun but will tolerate part shade. In very warm climates, some afternoon shade may be beneficial. Shadier conditions may produce leggy plants that require frequent pinching back to keep the plants full.

Soil

Soil should be well-draining, but not too rich. As with herbs and other plants grown for their essential oils, rich soil can lessen the strength of the fragrance. Scented geraniums will tolerate most soil pH, but a slightly acidic pH of about 5.8 to 6.3 is ideal.

Water

Scented geraniums are drought tolerant and don't like sitting in wet soil. Water when the soil feels dry about an inch below the surface. Prolonged periods of dry soil will cause the leaves to turn yellow, then brown and fall off, but the plant will come back again with regular water.

Temperature and Humidity

These plants are perennial in tropical climates, so are well-suited for hot, humid conditions. Geraniums also do well in very dry climates. They may survive short periods of light frost but should be brought indoors or discarded when the weather turns cold in winter.

Fertilizer

Go easy on the fertilizer. Scented geraniums are light feeders, and their scent will be stronger if they are grown on the lean side. Potted plants will need more fertilizer than plants in the ground, however. You can feed potted geraniums every three to four weeks through the spring and summer with an all-purpose fertilizer at half the label's recommended dilution. Do not fertilize at all during the winter.

Source: thespruce.com