<i>Pelargonium</i>, geranium: planting and growing
Contents
Pelargonium in a nutshell
- Pelargonium offers a long, generous flowering period, for much of the year, from May until frosts
- Always beautiful, low-maintenance, Pelargonium flowers offer a wide diversity of colours from pastel to the most vivid
- Foliage sometimes variegated, often scented with notes of rose, lemon, apple and even chocolate, which keeps mosquitoes at bay!
- Frost-tender, grown as an annual in open ground or in pots to overwinter: suits all regions
- King of balconies, hanging baskets and window boxes, also outstanding in beds and borders
A word from our expert
What would our windowsills, balconies, summer beds and borders be without Pelargonium, more commonly called geranium?
Unlike its cousin hardy geranium, Pelargonium is a non-hardy plant, frost-tender, generally grown as an annual unless brought indoors over winter to avoid frost. Growing it in the open ground is possible only in our mildest regions.
That matters not! It offers a wide diversity of shapes, colours, textures and scents to the point of provoking acute collectionitis!
Pelargonium comes in many varieties such as pelargonium zonale with velvety leaves marked by a darker zone, ivy geranium (Pelargonium peltatum) “king of balconies”, which forms flowering cascades all summer, florists’ pelargonium with large flowers, or scented pelargonium such as GĂ©ranium rosat (Pelargonium graveolens) whose foliage rich in essential oils exudes varied scents of rose, lemon, mint or even chocolate depending on cultivar and would help repel mosquitoes.
If the leaves of scented pelargonium are edible, its root is also used in phytotherapy for its purifying benefits.
It has a long, generous flowering period lasting six months of the year (or more if kept warm over winter), ranging from pure white to the most flamboyant red, which only the first autumn frosts interrupt.
Alternately elegant or borderline garish, it thrives in all gardens whatever their style: in beds, borders, rockeries, containers and hanging baskets.
Always beautiful whatever the weather, geranium flowers need only sun and some regular watering.
From care to pruning, discover our tips and fall for our exceptional collection of pelargoniums in mini plugs or for our geranium seeds so easy to sow! So why deprive yourself?
Description and botany
Botanical data
- Latin name Pelargonium
- Family Geraniaceae
- Common name Pelargonium, scented geranium, florist's geranium, balcony geranium
- Flowering April–May to autumn
- Height 0.15 to 1 m
- Exposure sun or partial shade
- Soil type All, well-drained
- Hardiness frost-tender
The Pelargonium, better known as geranium, is a perennial or an undershrub belonging to family Geraniaceae.
Native to mountainous regions of South Africa, Pelargonium is not hardy in our climates and is generally grown as an annual on terraces or balconies, unlike its cousin the hardy geranium, which is a hardy species that can remain in the ground in our gardens. Pelargonium is often wrongly called “geranium”. Geraniums and Pelargoniums are two distinct species, though they belong to the same family. Nevertheless, use of the name “geranium” for pelargoniums has remained common.
Genus Pelargonium includes about 230 species and nearly 1,000 varieties. Many cultivars and hybrids have been produced from around twenty species including Pelargonium grandiflorum, the florist’s pelargonium (Pelargonium x domesticum), Pelargonium graveolens or rose-scented geranium, the most fragrant of all, used in perfumery, and parent to many hybrids, Pelargonium fragrans, with a pine scent, Pelargonium crispum, Pelargonium peltatum or ivy geranium, nicknamed the “King of Balconies” for its trailing habit.
Today true botanical pelargoniums are rare, such strong hybridisation has occurred. Most cultivars fall into four main groups: ivy pelargoniums, with very trailing shoots much appreciated in hanging baskets and window boxes; zonal pelargoniums (Pelargonium x Hortorum), classic upright-stemmed types widely used in beds; “Regal” or large-flowered pelargoniums; and the scented pelargoniums, also called “scented geraniums”, whose leaves are aromatic.
There are also so-called Unique pelargoniums, undershrubs that can reach 1 m in height in a single season and whose foliage emits a strong, spicy aroma at the slightest touch.
Botanical illustrations: Pelargonium grandiflorum / Pelargonium graveolens / Pelargonium peltatum
With a rapid growth, the plant forms a bushy, dense clump, almost as wide as tall, with development varying from 0.10 m in height for dwarf and miniature varieties to 1.20 m for the largest pelargoniums. Some geraniums resemble a small bush with a spreading habit.
Habit varies by variety, erect in zonal geraniums that form a compact or very spreading bush, and trailing in the famous ivy geranium. Stems can reach 1 m in length.
Branching stems bear leaves that also show great variety: alternate, fleshy, rounded, lobed or pointed, deeply veined, downy or glossy, with dentate or undulate margins. Leaves are for the most part evergreen in regions spared from winter frosts.
They are leathery, smooth and shiny, resembling ivy leaves in ivy pelargoniums, rounded like fans, funnel-shaped in Pelargonium cucullatum and sometimes so lobed they recall maple leaves.
Leaves often have a long petiole, measure from 1 to 15 cm across and show every shade of green; bright green in ivy types, medium or tender green, sometimes variegated cream-white, golden or silver, or green-grey edged with red. They can be bicoloured or tricoloured. Many varieties feature decorative foliage such as ‘Mrs Pollock‘ and ‘Vancouver’ popular with collectors.
The zonal geranium (notably cultivars like ‘Fantaisie’) is distinguished by its round, very often zoned leaves (hence “zonal”), sometimes beautifully marginate with lighter tones and especially marked by coloured halos arranged in irregular concentric rings of brown, dark bronze-green, slate-blue or black or in “butterfly wings”, with a distinct tone at the centre of the leaf.
Diversity of foliage in Pelargoniums
The foliage of the scented pelargonium, rich in essential oils, is highly aromatic: leaves, rougher or softer, plicate, often deeply incised, release on crushing very varied scents of rose, lemon, green apple, citronella, orange, mint, eucalyptus, pine in Pelargonium fragrans, spices and even hazelnut, chocolate or carrot! Pelargonium x graveolens and rose-scented pelargoniums (P. capitatum), with a rose fragrance, are much prized in perfumery.
This aromatic foliage is said to repel mosquitoes.
Its edible leaves can also flavour fruit salads.
Dominating the foliage, flowering, often particularly long and abundant, appears from April to October depending on species or all year round for plants kept between 10 and 15°C. Pelargonium produces masses of single, semi-double or double flowers as pretty in bud as when fully open.
At stem tips, flowers grouped in terminal umbels, more or less large, renew throughout summer and contrast nicely with foliage.
Their form varies by species: zonal pelargoniums have large flower heads, single or double, gathered in handsome spherical clusters 5 to 13 cm across that stand out clearly from foliage, while ivy and scented geraniums produce countless smaller flowers in looser umbels. Flowering of aromatic-leaved pelargoniums, less showy, is more discreet and delicate.
Some flowers: Pelargonium peltatum ‘Big 5 White Angel’, Pelargonium ‘Mosquitaway Eva’, Pelargonium graveolens, Pelargonium cucullatum, Pelargonium ‘Paton’s Unique’ and Pelargonium ‘Wilhelm Langguth’
Flowers, made up of at least 5 to 6 petals, are bowl-shaped, star-like, trumpet-shaped, funnel-shaped or butterfly-shaped (two upper petals larger than three lower petals) and measure 1 to 4 cm across. Some resemble small roses (Pelargonium hortorum ‘Appleblossom’) or even dahlia-cactus flowers with twisted, rolled petals, or consist of fine pointed petals with scalloped edges (see Fireworks ‘Scarlet’).
Summer colours are not limited to the traditional bright red but range by variety in solid or multicoloured tones, vivid, rare, deep or pastel from wine-red, fresh pink, mauve, purple, pure white to, more rarely, yellow or salmon orange. These bright or velvety colours do not fade in the sun.
Some petals are veined, variegated with subtle bicolours or sometimes tricolours, showing small macules of varying contrast.
After flowering, flowers give way to fruits whose very elongated shape recalls a bird’s beak, hence name “Pelargonium”, from Greek meaning “stork”.
Typical beak-shaped fruits
Flower of the scented pelargonium, lightly perfumed, is edible and can adorn summer desserts such as sorbets.
Not hardy, pelargonium is somewhat tender and should be moved into a greenhouse in regions with cold winters. Drought-tolerant, it grows rapidly in light, well-drained, fertile soils, in full sun or preferably in partial shade in hot regions.
Geranium is an essential annual for summer displays, adding texture and colour to beds, sunny borders and edges, as well as to hanging baskets and window boxes on terraces, balconies or in conservatories.
For centuries, pelargonium root has been used in herbal medicine for its beneficial and cleansing properties against symptoms of respiratory infections such as bronchitis.
Main species and varieties
Not always easy to find your way among 230 pelargonium species! First distinguish the PĂ©largonium, which is frost-tender and grown in our latitudes as an annual, from hardy geranium, which is hardy and can remain in ground for years in the garden.
Pelargonium is wrongly called “geranium”. It was botanist Carl von LinnĂ© who in 1787 grouped both Pelargoniums and Geraniums under the same genus. About 25 years later French botanist L’HĂ©ritier noticed the mistake and created genus PĂ©largonium. Too late! the error persisted for a long time… These two plants do belong to the same family, the Geraniaceae, but that is their only common point!
One can distinguish several groups of pelargoniums, within which many cultivars have been created. Not forgetting the hybrids! They are adapted to every use and come in a multitude of colours, offering a great diversity of textures and scents!
- The pelargonium zonale (30–50 cm high): It’s the classic geranium, forming colourful mounds with upright stems, its handsome round, velvety leaves marked by a contrasting halo and its large flower heads in all shades of red, pink and white, plain or bicoloured. Part of the large group of hybrids Pelargonium x hortorum. Used in borders and window boxes.
- The ivy pelargonium (up to 1 m high): It’s the ‘king of balconies’, most used in pots, in window boxes or hanging baskets. It forms cascades of trailing or creeping flowers. Its glossy bright green leaves recall ivy.
- The PĂ©largonium with scented foliage: Its flowering is more discreet; its foliage, rough or velvety, is sometimes variegated with yellow or silvery tones, and above all it emits a variety of scents of apple, mint, spices, lemon or orange when crushed. P. x graveolens and P. capitatum give a rose-like scent, widely used in perfumery.
- The florist’s pelargonium or large-flowered pelargonium (Pelargonium grandiflorum): Also known as pelargonium “Regals”. It resembles the zonal geranium but has dentate leaves and much larger inflorescences. Often grown indoors or in a greenhouse.
Discover our unique collection of geraniums as plug plants or as seeds, including some exclusive varieties!
Pelargonium peltatum Balcon Imperial Red
- Flowering time June to December
- Height at maturity 20 cm
Pelargonium Brocade Mrs Pollock
- Flowering time June to November
- Height at maturity 45 cm
Pelargonium graveolens
- Flowering time July to October
- Height at maturity 60 cm
Collection of 10 Red and Pink Balcony Geraniums
- Flowering time August to December
Pelargonium peltatum Ruby
- Flowering time July to December
- Height at maturity 50 cm
Pelargonium hortorum Fireworks Pink
- Flowering time June to November
- Height at maturity 40 cm
Pelargonium Border Supreme F2 Seeds - Geranium
- Flowering time August to November
- Height at maturity 35 cm
Pelargonium hortorum Flower Fairy Velvet
- Flowering time June to November
- Height at maturity 35 cm
Pelargonium Cassiopeia
- Flowering time June to November
- Height at maturity 50 cm
Pelargonium Blanche Roche - Ivy Geranium
- Flowering time June to December
- Height at maturity 20 cm
Pelargonium crispum Variegatum
- Flowering time July to October
- Height at maturity 80 cm
Pelargonium Lemon fancy
- Flowering time July to October
- Height at maturity 60 cm
Discover other Pelargonium - Geranium
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Planting
Where to plant pelargonium or geranium?
Pelargonium is a plant native to South Africa, frost-sensitive and therefore somewhat tender in our climates. Below 0°C, pelargonium will not survive.
If it can remain in open ground in mild coastal climate and in regions spared by severe frosts, keeping its foliage even in winter, it will simply need overwintering in a cold greenhouse or conservatory at a minimum temperature of 10°C elsewhere or grown as an annual. You can thus keep it from one year to the next by protecting it from frost over winter and bringing pots out in fine weather.
Note, however, that Elisabeth, our Mediterranean climate specialist, grows a Pelargonium quercifolium in open ground. It has been there for five or six years, is over 1 metre tall and regrows readily from the stump after a light frost. And she never waters it!
Undemanding as to soil, naturally resistant to summer drought, weather-resistant, if content with good well-drained soil it performs best in rich, light soil.
From its South African origins it has retained a taste for sun and heat. It thrives in full sun or in part shade in southern France.
You can plant pelargoniums in open ground or in pots.
With decorative, sometimes scented foliage and such generous flowering, Pelargonium is essential in romantic, colourful or chic summer compositions. It is ideal in natural gardens.
Not hardy, it is star annual of summer displays with ephemeral charm, to be replanted each year as desired. Long reserved for hanging baskets and window boxes, balconies and terraces, pelargonium now features in flower beds, sunny borders and borders, where it quickly brings a very cheerful, colourful touch throughout the season.
Ivy geraniums with a trailing habit form flowering cascades ideal for hanging baskets and rockeries and are excellent as groundcover. They can also be trained on a trellis against a wall outdoors or in a winter garden.
The zonal geranium grows in colourful, compact clumps and is perfect in beds, pots and borders.
The scented geraniums work wonders as a low hedge or border along a path or in a large pot on a terrace or in a conservatory, never too far from home to enjoy their scent.
Finally, all are well suited to greenhouse cultivation.
When to plant pelargonium or geranium?
Planting of pelargonium or geranium is done in spring but timing varies by region. In mild-climate regions, you can plant our pelargoniums in plug plants as early as March–April. Wait until mid-May in the northernmost regions to set them in open ground. Meanwhile, you can pre-grow them in pots in a warm, bright place to accelerate their growth.
In all cases, on receipt, pot on and keep under cover (conservatory, greenhouse…) at a temperature above 14°C and wait until risk of frost has passed and soil is well warmed before planting or moving outdoors.
How to plant a pelargonium?
- In open ground
For a bold, colourful display, favour group planting. Allow 5 to 7 young plants per m² and leave about 20 cm between plants. It needs a light, humus-bearing but above all free-draining soil. If soil tends to retain water, be sure to add a layer of gravel.
- Loosen soil well
- Dig a hole two to three times the size of the plug plant
- Position the plug plant and cover without burying too deeply, adding a little leaf mould
- Firm down without damaging the young plant
- Water well at base
More advice on planting annuals in plug plants on our blog!
- Planting geranium in pot or window box
All geraniums are ideal for hanging baskets, window boxes, urns or containers, but ivy geraniums are used most often. A well-draining mix is essential to avoid stagnant moisture at the roots. Feel free to mix varieties for sparkling, floriferous combinations!
- In bottom of a drained container, spread a good drainage layer (gravel, broken pottery or clay balls)
- Plant in a geranium-type compost or a mixture of loam and compost
- Place in sun
- Water regularly, never allowing substrate to dry out between waterings: compost should always remain moist but never waterlogged
- Bring potted pelargonium out after frosts have passed
When and how to sow pelargoniums or geraniums?
Sowing of pelargonium seeds is done under cover from mid‑January to mid‑March. Young plants will be transplanted outdoors into open ground once all risk of frost has passed. They will flower in year of sowing.
How to succeed in sowing geranium seeds
- Sow geranium seeds 2 cm apart without burying them in a tray filled with seed compost
- Cover with 1–2 mm of compost
- Keep them warm at a minimum temperature of 18°C, ideally 20–25°C
- Keep compost moist but not waterlogged
- Germination occurs in 10–15 days
- When at four‑leaf stage, prick out young plants into individual pots or buckets
- In mid‑May, after all risk of frost has passed, transplant into ground, into pots or planters
- Pinch out tips of stems of young rooted cuttings fairly early to encourage their branching
Discover our tips to succeed in sowing annual seeds! and our advice sheet on the propagation by cuttings of Pelargonium
Maintenance, pruning and care
Le Pelargonium is an annual plant, very floriferous and grows without requiring much care.
In open ground, it tolerates lack of water quite well: water only during the first few weeks after planting.
Potted geraniums must be watered one to three times a week but not excessively, as soon as the soil dries at the surface: the substrate should remain moist.
The potted geranium is a heavy feeder, requiring weekly applications of liquid “geranium” feed from April to August to encourage continuity of growth and flowering.
Remove all first flower buds and pinch the tip of young plants to encourage their branching.
Regularly remove faded flowers and yellowing foliage to encourage the appearance of new flowers and extend the flowering period.
Pelargoniums do not tolerate frost. In autumn, dig up plants grown in open ground, discard them or temporarily replant them in pots of the same size or slightly smaller.
Bring pots indoors into a cool but bright place kept frost-free to preserve them from one year to the next.
→ Find out more about Pelargonium care in winter in our tutorial!
How to keep geraniums over winter?
Pelargoniums or geraniums can continue to flower throughout winter if kept between 7 and 10°C in a bright room. To learn all about overwintering them, see our advice sheet: Successful overwintering of Pelargoniums (balcony geraniums)
Potential diseases and pests
Pelargonium is susceptible to certain diseases and pests.
Cold and excess water can cause grey rot (botrytis) of the roots and stem base (black foot). Zonal Pelargoniums are susceptible to rust. In both cases, burn affected leaves and treat, if there is still time, with Bordeaux mixture.
Against whiteflies (aleurodes), hose foliage and keep slugs at bay naturally using our advice.
Its stems can also be attacked by the green caterpillar of a small brown moth called “pelargonium bronze”, which can quickly kill the plant. Cut off all affected stems.
Caterpillar and moth of the Geranium bronze (Cacyreus marshalli)
Also watch out for aphids, which can invade it: shower plants with soapy water to dislodge them.
More details in our article: Diseases and parasitic pests of Pelargoniums.
Multiplication
Pelargonium or geranium is easily multiplied by propagation by cuttings. Cuttings taken at the end of summer will flower the following spring.
When and how to take a geranium cutting?
In July–August, choose a healthy pelargonium and take several cuttings.
- With pruning shear, cut a stem without flowers about 10 cm long, below a node
- Remove all lower leaves, leaving only two upper leaves
- Trim the base at an angle and incise it with a sharp knife
- Insert into a perforated seed tray (you can also prick the cuttings into individual buckets) containing a mix of turf and sand, pushing the cuttings in to half their height and spacing them 10 cm apart
- Water generously
- Cover the container with a lid or a plastic bag
- Keep moist throughout winter in full light in a heated room at 12–15°C
- At the end of winter, repot them into individual buckets
- Plant out in ground or move pots outside around mid‑May
→ Read also : How to take cuttings from pelargonium or balcony geraniums?
Combining pelargoniums
With their bright or pastel colours, pelargoniums or geraniums adapt to every desire, in the ground or in pots to create often very colourful and cheerful displays throughout the summer season.
Examples of uses: in a window box with bright colours or in a border with pastel tones with Liriope muscari ‘Ingwersen’ or grasses such as Carex and small mat-forming sedums such as ‘Cape Blanco’, ‘Purpureum’, ‘Album Superbum’, sieboldii, etc
They are available in an endless range of colours, allowing infinite combinations, in gradients or monochrome, elegant and chic or sparkling! They suit every garden style, from the most romantic to the most naturalistic.
They accept company from many summer blooms, annuals or perennials.
In a refined summer border, pair zonal geraniums with white or pearly-pink flowers with purple ageratums, Buenos Aires verbenas and dense clumps of small mealy salvias.
In a multicoloured flowerbed, mix geraniums with dwarf dahlias and marigolds (they will help protect from whitefly).
They also combine very well with plants of lighter habit, such as cleomes, nepetas, tobaccos and cosmos.
One idea for a combination: Pelargonium ‘Mosquitaway Eva’, Lobelia ‘Hot Water Blue’ and Chamaesyce hypericifolia ‘Diamond Frost’
Paired with petunias, ivy geraniums will hide bare bases of a shrub rose throughout the summer season.
At edge of a colourful summer bed, pelargonium flowers pair nicely with contrasting blooms of zinnias, rudbeckias, and with pointed silhouettes of phormiums and cordylines.
Intense scarlet geraniums work well with bronze or purple foliage of heucheras, castor oil plant, dahlias and large cannas.
You can also use them to punctuate borders of grey-foliaged plants such as cerastium, Helichrysum, dusty miller or artemisia.
Ivy geranium can be trained against a winter garden wall, alongside other climbing annuals such as morning glories and ipomoeas.
Create stunning containers and hanging baskets by pairing them with Calibrachoa ‘Million Bells’, Bacopa, lobelias or Scaevolas.
Useful resources
- Discover our scented geraniums: their foliage exudes scents of rose, lemon, mint, spices and even carrot, more than capable of putting a squadron of mosquitoes to flight!
- Whether ivy-leaved, zonal or scented, Geraniums or Pelargonium are generous plants, stars of our gardens, terraces and balconies in summer — don’t miss out!
- With their romantic or very vivid colours, they are indispensable for composing “Happy” scenes throughout the summer season, take pride of place in a pink garden or a Catalan-inspired one and simply in a white garden!
- Our tips to choose an ivy-leaved geranium, king of flower-filled balconies all summer long.
- Discover our 7 ideas to create beautiful summer planters
- Find our advice sheet: 10 scented pelargoniums
- Discover our tutorial: How to prune a Pelargonium?
Frequently asked questions
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Why are the leaves of my geraniums turning yellow?
Not too much, not too little! That's what to bear in mind when watering geraniums. If water is lacking, leaves yellow and fall; conversely, excess water harms flowering and plant health, as roots may rot. Geraniums grow best in a light, very well-drained, well-aerated and fertile compost, both in the garden and in pots. In pots, water your pelargoniums once a week. Potted pelargoniums are fairly heavy feeders and, if short of fertiliser, foliage may also yellow. Remember to feed them well throughout the growth period.
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