Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
Contributions From JANEEN RANDLE
Janeen Randle is the president of the Melbourne Begonia Society. The society is based in Australia and many members, including Janeen, breed their own Begonias and visit flower shows across the country.
Jane Perrone is a Journalist turned Houseplant Expert who has over 25 years of experience. Jane published a book on Houseplants at the start of 2023 and is the founder of On The Ledge podcast, with more than 250 episodes to date. She is a member of the RHS Advisory Committee on Houseplants.
After working at Thompson & Morgan for 18 years, Michael Perry began his online brand ‘Mr Plant Geek’. He now runs his own podcast and has appeared on several TV shows in the UK, including This Morning, The One Show and Steph’s Packed Lunch. Michael was listed in the '20 Most Influential Horticulturists’ by The Sunday Times in 2015.
IN THIS GUIDE
The ever-popular Begonia is not a single type of plant or flower – it is a genus comprising over 1,900 species and over 10,000 cultivars.1The BRAHMS Project, University of Oxford, Department of Plant Sciences. (n.d.-b). Begonia species. Oxford University Plants. Retrieved March 13, 2023, from https://herbaria.plants.ox.ac.uk/bol/plants400/Profiles/ab/Begonia
Some gardeners may know Begonias as perennials; others as annuals.
Flower lovers may go crazy about the vast variety of blossoms; foliage enthusiasts are equally fixated on fancy-leaf hybrids.
In our Begonia guides we feature advice from Janeen Randle, President of the Melbourne Begonia Society.
“My passion for growing begonias stems from the variety and colour in the flowers and the foliage,” says Janeen.
“These plants produce long-lasting clusters of pendulous flowers with various leaf shapes that have interesting colouring, patterning and texture.”
Overview
| Botanical Name | Begonia |
| Plant Type | Annual / Perennial Flower |
| Native Area | South America, Central America, Central Africa and South Asia |
| Hardiness Rating | H1C-H3 (sometimes hardier) |
| Foliage | Varied genus |
| Flowers | Bright blooms in various colours |
| When To Sow | March, April, May, June |
| Flowering Months | June, July, August, September |
| When To Prune | June, July |
Sunlight
Preferred
Part Shade
Exposure
Sheltered
Size
Height
0.1 – 0.5M
Spread
0.1 – 0.5M
Bloom Time
June – September
Soil
Preferred
Loam
Moisture
Moist but well drained
pH
Neutral / Mildly Acidic
Begonias are herbaceous perennials in their native habitats in the tropical and sub-tropical regions of South America, Central America, Central Africa, and Southern Asia.2An Introduction to Begonia Species. (2021, December 20). The American Begonia Society. Retrieved March 13, 2023, from https://www.begonias.org/introduction-to-begonia-species/
Because they cannot survive a frost, most varieties are grown as annuals in the United Kingdom.
However, some varieties can be grown indoors, besides in greenhouses, as perennials.
For example, B. semperflorens or wax Begonias are effectively annuals in temperate regions but can live for several years in tropical climates or controlled environments.
“If I was going to recommend a houseplant to a beginner, I’m drawn to the various different types of begonia,” shares Mr Plant Geek Michael Perry.
“They can be a little fussy, as they don’t like to be over or underwatered, but they let you know in a simple way by just wilting a little.
“You know then to just give them a little bit of water. You can’t get it wrong with them, they can be divas, but they are easily fixed. They also provide so much colour with their foliage.”
Advances in Begonia horticulture occur at a dizzying pace.
Wax and cane-like begonias would best be described as petite and cute varieties for beds and small pots, as these plants grow to about 15cm and no more than about 22cm at most.
How things have changed! Newer cultivars are big, beautiful beasties; they average 40cm and the tallest reach a height of 85cm.
What is more, they branch repeatedly so that besides being big, they are also broad and bushy.
As for the blooms and the leaves, they are colourful, striking and vibrant.
Habitat & Growing Conditions
For the most part, Begonias are understorey plants that grow in the cool and moist conditions of a rainforest canopy in their native habitats, for example, Cameroon and Malaysia.
Some tuberous varieties thrive in dry and cool climes like those of the Peruvian Andes.3Moonlight, P. W., & Reynel, C. (2018). Two new species of Begonia from Andean Peru. Phytotaxa, 381(1). https://doi.org/10.11646/phytotaxa.381.1.15
Others grow in the wild on moist, shady slopes.
Begonia habitats are the tropical and subtropical regions of South America, Central America, Central Africa, and Eastern Asia, with Southern China, Ecuador, and Cameroon being particular centres of diversity.
Other countries which boast their own brands of Begonias include Ecuador, Andean Peru, Brazil, Colombia, Venezuela, Mexico, Cameroon, Equatorial Guinea, India, Peninsular Malaysia, Borneo, Southern China, Vietnam, Philippines, and the Koreas.
A few Begonias are native only to isolated areas in remote locations such as Sao Tome, the Bolivian Andes, and New Guinea; in contrast, Begonia cucullata grows freely across a huge swath of land in Argentina, Brazil, Paraguay, and Uruguay.
The famed Begonia rex cultivars originate from the species which is native to North-East India and Myanmar.4Begonia rex Putz. (n.d.). Kew Royal Botanic Gardens. Retrieved March 28, 2023, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:105573-1
Regardless of the species or cultivar, the flowers of this genus are monoecious, that is, a given flower on a plant is either female or male.
Most varieties are hardy to H1C-H3.
Begonia grandis, also known as the Hardy Begonia, is a well-known exception that is winter hardy in temperate regions, being hardy to H5/H6.
Begonia Care
Caring for Begonia, as one of the most diverse genera, can scarcely be described in a one-size-fits-all section.
That said, three essential guidelines hold good for virtually the entire genus. These are:
- Begonias do not like strong, direct sunlight and do best in indirect or filtered sunlight or bright shade.
- They are susceptible to frost and must be protected from it.
- They do best with moderate and regular watering but are averse to wet soil.
“Although Begonias do not like wet soil, they also don’t like getting dry and can drop their flowers if they do,” advises Horticulturist Colin Skelly, whose experience includes time as a Skilled Horticulturist and Nursery Manager.
Everything else is a variation on these guidelines, apart from specific requirements, such as minimum winter temperatures.
Temperature & Sunlight
As understorey plants, Begonias generally prefer indirect or filtered sunlight, but stronger sunlight is necessary for Rex Begonia and its cultivars, keeping in mind that the darker-coloured the leaf, the more it can withstand strong sunlight.
Most Begonias do well in temperatures of 18-25°C but fare well in warmer temperatures provided they are kept under shade or a natural canopy.
Soil Requirements
The best soil has a moderate to slightly acidic pH of 5.6-6.5 which is of a loose, rich, loamy type.
“The aim is for the horticultural sweet spot of free draining but moisture-retentive soil,” says Colin Skelly.
“Add some horticultural grit to your compost to make sure that the compost drains freely and consider using pot feet to aid free drainage.”
Compost may be mixed with the soil; it should preferably contain coir but be free of peat.
Common Problems
Begonias can become infested by mealybugs and aphids.
You can treat either and both by using products like Safer’s soap according to the manufacturer’s instructions.
Aphids are a particular menace because of their rapid breeding and harmfulness.
Mealybugs on outdoor plants can be eliminated using nature to fight nature.
Release ladybugs, lacewings, and mealybug destroyers on the affected plants. These are beneficial insects that prey upon mealybugs.
Rex Begonias are particularly susceptible to nematodes.
While many nematodes are beneficial and even kill harmful insects, some are parasites that dwell in soil and destroy plants.
Garden centres usually stock some products for nematode infestation.
A few natural methods exist to eliminate nematodes, such as raising the soil temperature by sealing it off, but these cannot be used on soil inhabited by plants.
One semi-natural remedy that can be used to put down a nematode infestation is to put naptha mothballs on the soil, and water plants as usual.
Begonias, especially saplings and young plants, are delicacies for snails and slugs so be on the lookout for them and remove or eliminate them promptly so that their numbers do not get out of hand.
While waterlogged soil is harmful to almost all plants, even damp soil poses a threat to tuberous Begonia varieties as dampness can bring about rot.
Ensure that the soil is drained well and put containers on tiles or wedges so they are off the ground.
Although Begonias like some humidity, avoid misting them and do not expose them to overly humid environments to prevent mildew, as Jane Perrone, houseplant expert, explains:
“Lots of begonias really like humidity which you can check with a humidity meter. They like a humidity of around 50%, so it is a good plant for a bathroom or something similar.
“Begonias don’t like dry air, so don’t place them next to a radiator.”
Begonia Origins
The well-known name of one of the most popular plant families memorialises quite an unknown gentleman.
Way back in the 1600s, a French ancien regime official by the name of Michel V Bégon served in various ‘intendant’ positions in France’s colonies in the Caribbean.
This gentleman was passionate about plants and when he met with naturalist and botanist Charles Plumier, the latter was so impressed with the good intendant that he named a new genus after Monsieur Bégon.5Schumaker, P. (2020, February 13). The plant named after Michel Begon. UF/IFAS Extension Charlotte County. Retrieved March 13, 2023, from https://blogs.ifas.ufl.edu/charlotteco/2020/02/17/the-plant-named-after-michel-begon/
FAQs
Are Begonias Easy To Grow?
Begonias are among the easiest plants to grow, especially if they are propagated from stem cuttings or leaf cuttings which is possible to do with nearly all species and varieties.
Are Begonias Perennials?
In their native habitats, Begonias are perennials but in the temperate and cool climates of Europe they are annuals unless they are brought indoors to overwinter or kept in a greenhouse.
When Should I Plant Begonia semperflorens?
An ever-popular bedding variety, it is best planted in mid-spring via stem or leaf cuttings. See section Propagating Begonia for details.
