How To Grow And Care For Geranium

The plants we know as geraniums aren’t actually geraniums. If you point to a geranium at a garden shop, you're actually probably identifying a Pelargonium, a member of a group of plants that have commonly come to be called "geraniums." Botanically speaking, true geraniums (those belonging to the genus Geranium) are a related genus of hardy flowering perennial shrubs.

Because of their pretty blooms, lovely fragrances, and culinary uses, scented geraniums are a wonderful addition to herb gardens, borders, window boxes, and hanging baskets. Some can even be used as ground cover. Peppermint geranium is one that can spread and cover (as long as it won’t have to endure a hard frost). Plant in the spring once the chance of frost has passed.

Geraniums are popular plantings across the South. They grow quickly and add fragrant foliage and bright blooms wherever they're planted, whether that's in backyard garden beds or in pots, planters, and containers. Note that these plants are toxic to dogs, cats, and horses.

Plant Attributes

Geranium Care

While they require a little attention, geraniums are relatively easy-care plantings. They love full sun and well-draining soil. They are drought-tolerant but appreciate regular watering. Geraniums grown in containers should be watered more frequently since they tend to dry out quickly.

Light

This light-lover should receive full sun. When planted in containers, you can move the pot to adjust for natural conditions. If the plant appears to be sunburned, you can give it partial shade to help it recover. If the geranium leaves turn yellow and are slow to send up flowers, move the pot into the sun to supplement its natural light.

Soil

Plant in any good, fast-draining soil and amend poor soil with plenty of organic matter. Geraniums growing in good garden soil need little fertilizer; those in light, sandy soil should receive two or three feedings during active growth.

Water

Geranium requires moderate to regular watering. Geraniums planted in pots dry out faster than geraniums planted in garden beds, so you’ll need to water pots more frequently.

Temperature and Humidity

According to the Grumpy Gardener, "High summer heat can take its toll on these plants. Many common geraniums stop blooming in sizzling weather, a condition known as 'heat check.' (They'll resume blooming when cooler weather arrives.)." Grumpy recommends avoiding this by planting heat-tolerant geraniums; these include the 'Americana', 'Orbit', 'Cascade', and 'Summer Showers' series.

Fertilizer

Don't over-fertilize: Feed your geraniums with slow-release, granular fertilizer once in spring or with a liquid 20-20-20 fertilizer three times during the growing season.

Types of Geranium

If you search enough garden centers, you can probably find four or five different types of geraniums. Two, however, account for almost all of the sales. The first and most popular is the common geranium (Pelargonium x hortorum). It's also sometimes called a zonal geranium because its rounded, velvety, green leaves often contain a burgundy ring.

Most gardeners treat common geraniums as annuals, but in the Coastal and Tropical South where it doesn't freeze, they're perennials. Succulent stems become woody with age, and plants grow into picturesque shrubs. Outside these areas, you must store the plants indoors near a window during winter if you wish to grow them this way.

The second most popular type is the ivy geranium (P. peltatum), named for its glossy green, ivy-shaped leaves. Rather than growing upright like common geraniums, this one cascades. Use it to plunge from hanging baskets, window boxes, or the edge of a big planter.

Here are more of our favorites, for your consideration:

•  Heartleaf Geranium (P. cordifolium): This rounded plant grows to 4 feet tall and wide, with 2 1⁄2-inch, dull green, toothed and lobed leaves. It features loose clusters of reddish purple, 1-inch flowers and is good for borders.
• Lady Washington Geranium, Martha Washington Geranium (P. x domesticum): This variety is erect or somewhat spreading to 3 feet tall and wide. It is rangier than P. x hortorum with heart-shaped to kidney-shaped dark green leaves that are 2–4 inches wide, with crinkled margins and unequal sharp teeth. Loose, rounded clusters of large (2-inch or wider) showy flowers come in white and many shades of pink, red, lavender, or purple, with brilliant blotches and markings of darker colors. They can be planted in beds if pruned hard after flowering to prevent lanky, rangy growth. Some selections are used in hanging baskets. Most suffer during extended high temperatures, but the hybrid Grandirosa series is surprisingly heat tolerant.
• Common Geranium, Garden Geranium (P. x hortorum): This geranium is succulent stemmed and grows to 3 feet or more high and wide. In mild climates, older plants grown in the open become woody. Round or kidney-shaped leaves are velvety and hairy, soft to the touch, and aromatic with lobed or scalloped edges. Most selections show a zone of deeper color just inside the leaf edge, though some have plain green foliage. Flowers are single or double and they are flatter and smaller than those of P. domesticum, but clusters bear many more blossoms. Many selections are sold in solid white and shades of pink, rose, red, orange, and violet. Available strains include Americana (bright green foliage, compact); Eclipse (dark green foliage, compact); Elite (quick to reach blooming stage, compact, needs no pinching); Maverick (open habit with many flowering stems); Multibloom (compact, early blooming); and Orbit (distinct leaf zoning; broad, rounded flower clusters). 
• Ivy Geranium (P. peltatum): This grows to 1 1⁄2 feet tall, trailing to 3 feet wide. Rather succulent, 2- to 3-inch-wide, glossy, bright green leaves with pointed lobes resemble foliage of ivy (Hedera). Single or double, inch-wide flowers bloom in summer in rounded clusters of five to ten; colors include white, pink, rose, red, salmon, and lavender. Upper petals may be blotched or striped. Most types cannot tolerate extended heat and are grown as summer annuals only in the Upper and Middle South (though they perform well as winter annuals in the Coastal and Tropical South). However, heat-tolerant Blizzard, Cascade, and Summer Showers series perform well throughout summer in much of the Lower South, as well as farther north. Focus series is compact with dark leaves for dense baskets. Use ivy geraniums in hanging baskets, window boxes, and tall planters.
• P. hybrids: Crossing zonal geraniums and ivy geraniums has produced garden hardy selections. Double Take series has semidouble flowers that are slow to shatter. Calliope and Caliente series are a geranium lover’s answer to Southern summer heat. Place them where they get all-day sun in the Upper and Middle South, but afternoon shade in the Lower and Coastal South.
• Scented Geraniums: Many aromatic species, hybrids, and selections are available. Most grow 1–3 feet tall, spreading as wide as high. Foliage scent is the main draw; clusters of small, typically white or rosy flowers are secondary in appeal. Leaves vary in shape from nearly round to finely cut and almost ferny; they range in size from minute to 4 inches across. Common names usually refer to the fragrance of their leaves: almond geranium (P. quercifolium), apple geranium (P. odoratissimum), lime geranium (P. nervosum), nutmeg geranium (P. fragrans ‘Nutmeg’), peppermint geranium (P. tomentosum), several rose geraniums (P. capitatum, P. graveolens, and P. ‘Lady Plymouth’), and several lemon (P. crispum and P. c. ‘Prince Rupert’). All scented geraniums are good for herb gardens, edgings, front of borders, window boxes, hanging baskets; peppermint geranium makes a good ground cover in frost-free gardens. Use fresh leaves to flavor jelly and iced drinks; use dried leaves in sachets and potpourri. 
  

Pruning

Geranium doesn't need to be pruned. Rather, you’ll need to deadhead geranium. To tend them during the blooming season, remove wilted and faded flowers. This will encourage new blooms to shoot up. You can also help shape the growth by pinching the growing tips of young geraniums to bring out branches along the sides of the plant.

Propagating Geranium

Geraniums are easily propagated by cuttings or in water to make new plants. Take cuttings at any time of year, but ideally in early spring or summer when the plant isn’t in full bloom yet. 

1. Use clean pruning shears to cut a 4- to 6-inch length from a healthy stem. 
2. Cut the stem just above the node that connects it to the main plant.
3. Remove the lower leaves, leaving a few at the top of the stem.
4. Dip the end of the cutting into rooting hormone.
5. Place the cutting in a jar or vase filled with water. Change the water every few days.
6. After about four weeks, the cutting will have formed roots. Transplant it to a well-draining pot filled with soil.

To propagate in soil, follow the directions above but place the cut stem dipped in rooting hormone directly into a small pot filled with damp soil. Place in bright, indirect light and keep moist.

How To Grow Geranium From Seed

The best time to start geranium from seed is in late winter. Using clean planting flats, fill with moistened planting mix, and press into each opening. Make a shallow indent with your finger and sow the seed following the directions on the geranium seed package. Press the seed in the soil and lightly cover with the planting medium. Lightly water the soil and put the planting flat under a grow light.

Once the seedling has two or more leaves, transplant it into a small nursery pot. Before planting, set the pots outside in dappled shade to build the plant’s outdoor endurance. After a week, plant the geraniums in pots, window boxes, or planting beds. 

Potting And Repotting Geranium

Caring for geraniums in pots is similar to caring for the plants in a garden. Geraniums need moist, well-drained, and nutrient-rich soil. Growing geraniums in pots means they can easily be moved around the yard for more light or inside for winter. Use a pot large enough to accommodate the plant that has drainage holes, and fill it with a good-quality potting mix. Amend potting soil with organic matter to assist with drainage. Add the plant, and moisten the soil. Place it in a sunny spot where the plant will get at least six hours of light per day.

Since geraniums like to be root-bound, they don’t need frequent repotting. Choose a pot that is slightly larger, about 1 or 2 inches, than the pot it is in when repotting. 

Overwintering

Before the first frost, bring your container indoors and place it in front of a sunny window for at least six hours per day at a temperature above 50°F. Or let them go dormant in a cool, dark place where they won't freeze, like the garage. Let the soil dry to barely moist, and remove dead leaves and flowers and any rot. After the last frost in the spring, place the pot outdoors each day, slowly exposing it to more sun, to acclimate the plant to warmer temperatures and resume waterings. Once the temperature is above 50°F at night, resume feedings.

Common Pests

If your plant has buds that won't open or you see tattered petals, your geranium could have an infestation. Common pests include aphids, spider mites, and whiteflies. Tobacco budworms may be a problem in some areas. Most pests are controlled by spraying with neem oil or spinosad to treat.

How To Get Geranium To Bloom

When it comes to caring for geraniums, according to The New Southern Living Garden Book, you should "plant in any good, fast-draining soil and amend poor soil with plenty of organic matter. Geraniums growing in good garden soil need little fertilizer; those in light, sandy soil should receive two or three feedings during active growth." To tend them during the blooming season, you should regularly remove wilted and faded flowers. This will encourage the appearance of new blooms. You can also help shape the growth by pinching the growing tips of young geraniums to bring out branches along the sides of the plant.

Common Problems With Geranium

Gardeners don’t encounter many problems with geraniums. If their growing conditions aren’t right, the leaves are usually a sign that the plant is struggling. Here’s what to do if you see yellowing or curling leaves.

Leaves Turning Yellow

Yellowing leaves can be caused by several things: watering, weather, sunlight, and disease. To ensure the plant isn’t getting too much or too little water, make sure it has well-draining soil and is in a pot that has drainage holes. Give it water only when the top inch of soil is dry. Geraniums don’t like soggy soil. If the plant is in a spot where it gets too much rain, move it and let it dry out. The tips and edges of a geranium will turn yellow first if it is underwater.

If water isn’t the issue, make sure the plant is getting enough sun. The leaves will turn yellow if it’s too shady. Geraniums do not like cold temperatures, so a cold snap may cause yellowing leaves. The leaves of geraniums grown as perennials will also turn yellow as the plant approaches dormancy. New green growth will return in spring.

Leaves Curling

When the sun is too hot for a geranium, it responds by curling its leaves. In hot climates, give the plant morning sun and afternoon shade. A geranium will also curl its leaves during drastic temperature changes. Indoors, maintain a consistent temperature and keep the geranium away from drafts.