Pelargonium

( pel - ar - GOH - nee - um )

At-A-Glance Information

Common names for this genus include Geranium and Storksbill, and species typically need some shade in warmer climates and moderate to regular water to perform well. These flowers will attract birds to your garden. They are frost-tender and woody-based natives of South Africa and have succulent-type stems and leaves, with flowers held in clusters. They perform best in areas with warm dry days and cooler nights. All types of Pelargonium do best in containers; they bloom well when they are somewhat pot-bound. Geranium leaves can be used to flavor teas and jellies. Use Pelargonium to add easy bloom color to containers, borders, mixed beds, or hanging baskets.

Pelargonium Species and Varietals

The genus Pelargonium is the second largest genus member of the plant family Geraniaceae, and includes around 280 species. Pelargoniums grow best in zones 8, 9 and 12-24. To find your zone, click here: Zone Map.

Pelargonium acetosum (Sorrel Cransebill, Sorrel-Leaved Pelargonium)
These plants are native to the eastern Cape Provinces of South Africa, and reach up to 2 feet tall when mature. Flowers are salmon-pink. Young leaves are sour and used in the plant's native range in a way similar to Sorrel (Rumex).

Pelargonium album
Native to South Africa, these plants produce apple/mint scented foliage and small white flowers. These are compact, semi-succulent plants that prefer light shade. They reach up to 6 inches tall and 16 inches wide.

Pelargonium australe (Native Storksbill, Wild Geranium, Austral Storksbill)
These plants reach 20 inches tall when mature and in bloom, and flower between October and March in the species' native range (Australia). These flowering subshrubs grow naturally on sand dunes, coastal cliffs and rocky outcrops and are great coastal garden plants. Flowers are white with pink-violet to magenta markings.

Pelargonium capitatum (Rose Geranium, Rose-Scented Pelargonium)
This species, native to South Africa, forms a low shrub that reaches 40 inches tall. Stems and leaves are green and soft, covered with hairs. When brushed, plants emit a rose-like scent. Flowers can be white or shades of pink to purple. These are vigorous growers, and can grow in most substrates, including clay. There are many cultivars of this species, outlined below.

'Atomic Snowflake'
Foliage has a lemony-rose scent and flowers are light pink.

'Attar of Roses'
With large heads of pink flowers that have darker pink markings. Foliage has a sweet scent.

'Rober's Lemon Rose'
Lemon-scented foliage and pink flowers.

'Round-Leaf Rose'
This variety has rose-pink flowers and light green rose-scented foliage.

Pelargonium cordifolium (Pelargonium cordatum)
This rounded plant grows to 4 feet tall and wide, and produces clusters of reddish purple flowers, These plants are fantastic in border gardens. They are endemic to the Southern Cape of South Africa.

Pelargonium domesticum (Lady Washington Pelargonium, Martha Washington Pelargonium, Regal Geranium)
Leaves on this species are dark green and appear on a plant that is 3 feet tall and wide. Flowers come in many colors, including pink, red, lavender and purple blotched with darker colors. Great for containers or hanging baskets.

Pelargonium grossularioides (Gooseberry Geranium, Coconut Geranium)
These plants are native to South Africa, and have naturalized in other parts of the world, such as California and India. They are sometimes grown as garden ornamentals. Leaves are green to reddish, and flowers are pink to dark reddish-purple, blooming in large inflorescences.

Pelargonium x hortorum (Common Geranium, Garden Geranium)
This hybrid species of Geranium has stems that are succulent, and gets to 1-2 feet tall and just as wide. Some varieties have plain green foliage, others have banded leaves. Flowers can be single or double and come in white, pink, rose, red, orange, lavender-blue and violet. There are many interesting varieties in this group of Geraniums, some of which are outlined below.

Americana Series
Uniformly branched plant that has a good resistance to heat.

Rocky Mountain
Good, vigorous, heat resistant strain of Geranium.

Black Velvet
With purple-black foliage edged in bright green, with large multicolored flowers.

Pelargonium inodorum (Wild Pelargonium)
This short-lived perennial species is native to New Zealand, Tasmania, Victoria, Queensland, and New South Wales, and has scented leaves and pink flowers. Individual plants reach up to 14 inches tall.

Pelargonium inquinans (Scarlet Geranium)
Endemic to South Africa, this species produces a small shrub that reaches up to six and half feet tall. Flowers are scarlet-red and bloom in large inflorescences at stem tips and are present for most months of the year in the plant's native range.

Pelargonium odoratissimum (Apple Geranium, Apple Pelargonium)
This species produces foliage that has a distinct apple scent. These small shrubs have a spreading habit and reach 12 inches tall and 24 inches wide. Flowers are pale pink and small. Leaves are waxy and green. These plants are commonly grown as houseplants and as garden ornamentals. They also have uses as medicinal plants.

Pelargonium peltatum (Ivy Geranium, Ivy-Leaved Pelargonium, Cascading Geranium)
Reaches 1.5 feet tall and 3-5 feet wide. Leaves are bright green and succulent, and flowers can be single or double in colors that include white, pink, rose, red and lavender. Upper petals may be streaked with darker colors. Select varieties are described here.

Freestyle Series
This semi-trailing group comes in a wide range of colors.

'L'elegante'
White-edged foliage.

Summer Showers Strain
Mixed-color blossoms in combinations of white pink, magenta, red and lavender.

Galleria Series
Flowers that come in red, coral and pink tones on vigorous, heat-resistant plants.

Caliente Series
This group of Geraniums has a high heat resistance and comes with flowers in warm, rosey tones.

Pelargonium quercifolium (Oakleaf Geranium, Oak-Geranium, Almond Geranium)
These natives of South Africa are commonly grown as ornamental plants around the world. These dense-branching shrubs typically reach about 4 feet tall and wide, and produce aromatic foliage. Flowers are pink with darker pink to magenta markings, and bloom through most of the year in areas with mild climates.

'Giant Oak'
This species has balsam-scented blotchy leaves with pink flowers.

'Royal Oak'
This variety has pink flowers are dark leaf veining.

'Chocolate Peppermint'
With dark blotched leaf centers and a slight minty scent.

'Clorinda'
Sweet-scented leaves and large pink flowers.

Pelargonium radens (Rasp-Leaf Pelargonium)
This species reaches up to just under 5 feet tall when mature, and produces deeply cut gray-green leaves. In summertime, pinkish-purple flowers bloom in terminal clusters. These plants are native to South Africa. There are many garden ornamental cultivars of this species, including:

Candy Dancer
With rose-scented foliage and white and pink flowers.

Crowfoot
With finely divided green foliage and pink flowers with dark pink markings.

Dr. Livingstone
With rose-scented leaves and light pink flowers with dark pink markings.

Red-Flowered Rose
Reddish-pink flowers.

Pelargonium sidoides (African Geranium, South African Geranium)
Slow grower to a foot tall and wide, with with silvery-grey leaves and dark purple flowers on trailing branching stems. These plants are native to South Africa and grow well in grasslands in rocky soils.

Pelargonium 'Splendide'
This species reaches 1-1.5 feet tall slowly and has silvery-grey leaves. Blossoms are dark red and white. This species is great for hanging baskets and for container plantings.

Pelargonium tomentosum (Peppermint-Scented Geranium)
This species is native to South Africa and is a tall, spreading species that reaches up to 40 inches tall and wide. Foliage is very soft and hairy, and has a strong mint-like scent to it. Leaves are green-grey to green and flowers are small and white.

Pelargonium vitifolium (Grapeleaf Geranium)
A plant with foliage reminiscent of those on Grape (Vitis) plants. These common garden ornamentals take the form of erect shrubs to 40 inches tall. Leaves are green and aromatic and flowers are pink with purplish markings.

Caring for Pelargonium

Pelargonium plants are typically purchased as specimens from a reputable nursery, but can also be grown from seed started indoors and then planted out into the landscape. Choose a space that receives full sun to partial shade; these flowers appreciate between 6 and 8 hours of sun each day to bloom well. They can tolerate partial shade, and in very warm climates, this exposure can be very beneficial. Typically, Pelargonium plants grown in too much shade will become leggy and require frequent pinching back to attain a bushy appearance. Ensure that soil is well-draining and lightly fertile. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Take care when adding amendments, however, as soils that are too rich can lessen the strength of the fragrance emitted by these plants. They grow well in a soil that has a pH of between 5.8 to 6.3 (slightly acidic). Apply a thick layer (2-3 inches) of mulch around the planting area after installation to suppress weed growth, maintain consistent soil temperatures, and increase soil moisture retention.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Water new plantings regularly as they establish a strong root system. At maturity, these plants appreciate a consistently moist soil. As a general rule of thumb, water whenever the top inch or two of soil feels dry to the touch. They can handle periods of drought very well, but prolonged periods without water will cause foliage to yellow and drop from plants. Geraniums typically are quick to bounce back, however. When plants are young, tips can be pinched to encourage a more bushy habit. Ongoing pruning involves removing dead, damaged, or diseased foliage and deadheading flowers. In springtime each year, these shrublets can be pruned for shape and size. As a rule, never cut back more than a third of the plant at any one time.

Growing Pelargonium in Containers and Hanging Baskets
These plants can grow well in the ground, but love container culture. They appreciate being somewhat root-bound, and flower and perform well under these circumstances. Choose a container that has great drainage holes in the bottom, and fill it with a well-draining, somewhat fertile potting mix amended with plenty of organic material and/or compost. Pots should be about 2 inches wider and deeper than the original nursery pot. Over time as plants grow, they will need to be potted up. Choose a pot that is just a bit larger than the previous one (one inch wider and deeper). Water regularly to keep the soil consistently moist, and prune plants to control for size and to remove spent flowering heads.

Harvesting Pelargonium
Pelargonium, or Geranium, plants have a few uses beyond the garden, including as a potpourri ingredient or to flavor teas and jellies. To harvest for use in potpourri, clip off healthy leaves and store them in a paper bag for about a week in a cool, dark, dry area with good ventilation. The leaves, once completely dried, can be crumbled into a mix with other dried fragrant plant parts. They are very fragrant due to their essential oil content, and can be displayed in bowls or used to fill sachets.

Propagation

Pelargoniums can be propagated best in two ways: by seed or by cutting. If you are looking to create an exact replica of your plant, you will want to use the cutting method of propagation, as propagation by seed does not guarantee a clone of the parent plant.

Propagating Pelargonium by Seed
To propagate via seed, gather the following materials: a bag, a pot (or planting tray), soil that is one part compost, two parts sand with a little limestone added in, and a spray bottle with water. Follow these directions to propagate your Geranium from seed:

In late summer, leave some of flowers on your existing plant and allow them to come to seed. Remove the seed pod cluster after it has dried, turned brown and some of the seed pods have begun to open and release their contents. Harvest the seeds from the seed pods and place them in a bag. This plant can self-sow if the conditions are right, but to ensure a new plant from seed, it is best to sow indoors in wintertime. Store your harvested seeds in a cool, dark place until about 10-12 weeks before the last frost of spring in your area.
Prepare your pots or seed trays with your potting mix and water to ensure drainage is occurring. Plant more seeds than you want new plants, as not all seeds will germinate. Place your seeds on top of the soil and cover with more potting mix. Water. Place your seed pots or trays in an indoor area that stays around 60 degrees Fahrenheit and receives bright indirect light, or place them in a greenhouse.
The seeds will take between 30 and 90 days to germinate. After the danger of frost has passed in your area, you can transplant your new Geranium outside in its garden location.

Propagating Pelargonium by Cutting
The best time to take cuttings from an existing plant is in spring or summer. To propagate by cutting, you'll need clean, sharpened garden shears, potting mix (one part compost, two parts sand and a little limestone added in), a pot (or pots, depending on how many cuttings you'll be taking), rooting hormone and a pencil. Once you've gathered your materials, follow these instructions:

Choose a Geranium plant to propagate. It should be a healthy plant, with new growth and should get some water the night before you take your cutting. Pick a healthy stem tip that has about three or four buds on it and make a 6-inch cutting. Cut quickly and evenly to take the healthiest cutting possible.
Add potting medium to your pot, and give it some water, ensuring that it has good drainage. Make a hole with your pencil in the medium, about two inches down. Dip your cutting in rooting hormone and place it in the hole. Fill in soil around it. Pat down just enough so the cutting stands up by itself. Give it some water.
Keep the soil around your plant somewhat moist as it grows, and ensure that it is in a place that gets bright indirect light and stays at a temperature of between 50-60 degrees Fahrenheit. Once the danger of frost has passed the next spring, you can transplant your cutting to its final home outdoors.