how to plant, grow & care for pelargoniums
complete growing guide
Pelargoniums are low-maintenance, high-performing, good-looking tender perennials. A really beautiful, bushy pelargonium filling a handsome pot during the summer is a wonderful thing to see – and useful, too, as the scented leaf varieties can be used in cooking, teas and cordials, and all pelargoniums can be used in stunning posies.
There are varieties grown for their flowers that bring vibrant colour from June until November, and there are the scented-leaf pelargoniums that, when you brush past them, fill the air with scent, and then there are wonderful ivy-leaved pelargoniums with a trailing habit that are suited to hanging baskets and window boxes.
Find out more about the different types in my guide to pelargonium groups, and discover our range of pelargonium seedlings, cuttings and plants.
details
- Common name: Pelargonium
- Latin name: Pelargonium
- Type: Tender Perennial
- Height: 30cm (1ft) to 90cm (3ft)
- TLC rating: Easy
- Aspect: Full Sun
- Planting position: Borders, Containers
- Suitable for pots: Yes
- Good for pollinators: Yes (mainly single zonal, regal, angel & scented types)
- Good for cut flowers: Yes
calendar
how to grow pelargoniums
where to grow pelargoniums
Soil type: Pelargoniums can tolerate most soil types, but fertile, moist and well-drained soil is best.
Aspect & position: Most pelargoniums prefer full sun, but those in the regal group, such as ‘Lord Bute’, will tolerate part shade. P. tomentosum thrives in quite deep shade (which makes it a perfect houseplant).
when to plant pelargoniums
They should be planted out after the risk of frost has passed, usually May. Seedlings and young plants should be hardened off before planting out.
how to plant pelargoniums
planting pelargoniums
Pelargoniums can be grown as bedding plants outside during the summer months, but they are not hardy so must be brought inside before the onset of frost.
Plant out pelargoniums after the risk of frost has passed, usually during May depending where you are in the country. If you’re planting out young plants, gradually acclimatise them to outdoor conditions over one or two weeks before planting in their final position.
Plant in fertile, moist soil spaced around 45cm (18in) apart. Water them in well.
growing pelargoniums in a pot
Pelargoniums are ideal container plants and look fantastic in a colourful group or on a windowsill for Mediterranean charm. They are tender perennials, which means it’s unlikely they’ll survive winter outside – grown in pots, they can be brought indoors as winter houseplants, or moved to a conservatory or greenhouse.
If you have bought young plants, grow them in 9cm (4in) pots, and once they have filled those, pot on into 2-litre pots. Grow in peat-free potting compost or in John Innes No 2.
Protect plants from frost in a sheltered environment while you pot them on ready to go outside, usually in May. A greenhouse is perfect but a windowsill or conservatory will do fine as long as they are getting plenty of sunlight. Gradually acclimatise plants to outdoor conditions for a week or two before moving to their final position.
When you’re ready to plant them in their final containers outside, incorporate a slow-release fertiliser into the potting mix. Water them in well.
Pelargoniums look brilliant together in a display, with a mix of textures and rich colours.
how to care for pelargoniums
watering
Water your pelargoniums every two to three days during their active growing season.
Take care to water sparingly during the winter, when the plants are undercover. If kept at 7-10ºC (45-50ºF), plants may continue to grow right through the winter. Otherwise cut back your plants by two-thirds and keep them almost dry until they begin to shoot in the spring, when regular watering can start again.
fertilising
Feed your pelargoniums with a homemade feed of comfrey juice or organic liquid plant food – both rich in potash – every fortnight while in flower.
deadheading
Deadheading pelargoniums regularly helps prolong flowering – do this more often during rainy periods because damp spent flower heads could become susceptible to botrytis. To deadhead, snap the flower off where it joins the stem.
propagating
Propagating pelargoniums from cuttings is easy. If you propagate them rather than growing on last year’s plants, you'll have more floriferous and stronger plants.
Start propagating pelargoniums in September, while plants are in an active stage of growth. They will root very quickly.
To do this, take a cutting that’s about (1½-3in) long using a very sharp knife. Remove any lower leaves or flower buds and the leader (the apical shoot). Insert the cuttings around the edge of a pot filled with a mix of two-thirds peat free multipurpose compost to one-third grit.
Do not cover your pelargoniums (as you might when propagating other tender perennials). Leave them somewhere warm, ideally on a heated mat or warm windowsill, and keep the compost moist.
They should root within two to three weeks. You'll know they have done so by new growth at their tips and new white roots at the base of the pot.
Keep them frost free and just moist through the winter, and pot them on into individual pots in early spring. They'll grow fantastically and you'll have lots of plants to put out in the garden in summer.
Some pelargoniums can also be grown from seed but they will need to be started early in spring in a heated propagator.
overwintering
If your pelargoniums are in the ground, lift the plants out, pot them up and bring them inside before the frost. If they are already in pots, bring them undercover. A greenhouse or potting shed is good, or you could bring them indoors as winter houseplants.
If kept at 7-10ºC (45-50ºF), plants may keep growing and even flowering right through the winter. Otherwise cut back your plants by two-thirds. They don’t go into complete dormancy, so water lightly through the winter until they begin to shoot in the spring, and then more regular watering can start again.
In spring, begin feeding and increase watering. Plant out only once any danger of frost has passed.
It’s worth noting, that at Perch Hill, we’ve found that in a very sheltered spot, varieties such as ‘Attar of Roses’ will get singed by frost, and look half dead, but if you leave the frost-burnt tops on the plants as a sort of mulch, the plants often survive the winter outside and grow off bigger and better in spring. This is great for foliage for flower arranging, but they won’t flower as much as newly rooted cuttings.
seasonal checklist
spring
- Plant out at the end of spring, once the risk of frost has passed.
summer
- Deadhead your pelargonium plants to encourage further flowering.
- Feed and water your pelargoniums regularly.
autumn
- Take cuttings to grow new plants.
- If you need to lift pelargoniums out of borders to overwinter, make sure you have large pots ready.
winter
- Bring undercover to protect them from winter frosts.
pests, diseases & common issues
botrytis
Botrytis (sometimes known as grey mould) is a fungus which affects plants under stress. Symptoms include shrivelled leaves and fluffy grey mould. Damp and cool conditions can lead to botrytis, so ensure good air circulation around plants and tidy up any dead or dying leaves and plant material sitting on the compost or soil.
rust
Rust is a fungal disease and shows up as brown spots on the underside of the leaf and yellow spots on the leaf surface. It affects zonal pelargoniums (these are the ones with a darker coloured ring or ‘zone’ on the leaf) and is often due to damp or humid conditions.
Make sure there is good air circulation around the plant and they are not in a humid, damp or overcrowded place.
why do pelargonium leaves turn red?
Red leaves can be a sign of stress, perhaps from cold temperatures, overwatering or lack of nutrients. Check your plant is getting enough sunshine and don’t plant it out until the weather has warmed in late spring.
why do my pelargoniums have spots?
This is likely a sign of rust, which affects zonal pelargoniums (these are the ones with a darker coloured ring or ‘zone’ on the leaf).
why do pelargonium leaves turn yellow?
Yellowing leaves could be a sign of overwatering, or potentially of rust or botrytis.
why are my pelargoniums wilting?
Pelargoniums are drought tolerant so only water once the soil is dry. Overwatering, or damp and wet weather, can lead to wilting and yellowing leaves.
why do my pelargoniums have holes in them?
This could be the work of caterpillars.
frequently asked questions
when do you take pelargonium cuttings?
We’ve found that the best time to take cuttings is in September, when pelargoniums are in active growth.
how do you deadhead pelargoniums?
Deadheading pelargoniums regularly helps prolong flowering – do this more often during rainy periods because damp spent flower heads could become susceptible to botrytis. To deadhead, snap the flower off where it joins the stem.
what is the difference between a geranium and a pelargonium?
There is often confusion between these two, but geranium is a separate plant genus to pelargonium, they are hardy perennials. Pelargoniums are referred to as ‘tender geraniums’.
when is the best time to sow pelargonium seeds?
Most pelargoniums can be bought as seedlings, cuttings or young plants and are best grown this way. You can sow seed undercover in early spring, but collected seed is unlikely to come true to the parent plant unless you have a species seed.
when do pelargoniums flower?
They flower throughout summer and into autumn if kept well fed, watered and deadheaded.
how do you prepare pelargoniums for winter?
Pelargoniums need to be brought undercover to a frost-free place over winter. For more on this see overwintering.
how to cut & arrange pelargoniums
Pelargoniums can look good for up to three weeks in the vase, which is a fantastically long-lasting cut flower. They also look stunning in posies. And it’s not just the flowers that have appeal – many varieties have wonderful foliage on upright stems, which create excellent bases for small flower arrangements and posies.
Get more inspiration for displaying your flowers with our flower arranging videos:
