Begonias

Begonias have been collected in Africa, South and Central America, India, southern China, Vietnam, Malaysia, the Philippines, Indonesia and Papua New Guinea.

Although Begonias face fierce competition for light and nutrients on rainforest floors, their habitat is inherently moist. Instead of putting energy into growing deep roots they have adapted to grow large leaves which help them to catch as much of the low light as they can.

Water-loving Begonias may also be found in the wild on steep slopes or rocks near waterfalls and streams, or in damp caves. There are even epiphyte Begonia species that can be found clinging to trees and branches.

Begonias have asymmetric leaves, and their flowers are monoecious, which means that both male and female flowers are found on the same plant. The Begonia’s ability to adapt to environmental triggers over many thousands of years has led to them being ideal for cross-breeding and propagating, and thousands of hybrids have been bred both commercially and by hobbyists. 

Begonia is both the common name and the botanical name for all members of the genus. Begonia varieties have been separated into nine distinct sub-groups to make them easier to describe. Their differing habits offer many and varied blooms, some of which are lightly fragranced, and striking foliage that is often textured, which makes them an exciting plant for home gardeners who want to get to know a single plant family.

Begonia varieties:

• Rhizomatous: Compact and grown for their highly patterned and textured leaves and stems, Rhizomatous Begonias grow from a ground-stem or rhizome

• Rex: Rex Begonias are a type of Rhizomatous Begonia grown for their dramatic, multi-coloured foliage

• Semperflorens: One of the Begonias that can be eaten raw, Semperflorens are used as bedding plants because of their abundance of flowers

• Shrub: This group branches often, has a low-growing habit and interesting foliage which may be hairy or velvety

• Thick-stemmed: One of the lesser-known varieties, if you like foliage and branches they may be the plant for you. They do not flower often, need more room, like more light and have deeper roots than other Begonia types.

• Trailing: These Begonias are grown as ground covers and climbing plants. They are ideal in hanging baskets because of their trailing habit and will also grow up posts and trellis’ with a bit of help.

• Tuberous: Tuberous Begonias have been bred to have large, eye-catching flowers. Some of them die back in winter and emerge from their tubers again in Spring

• Elatior: This Begonia type is the result of cross-breeding experiments with winter flowering species’ that could be grown indoors in the early 1900s. They now grow year-round and are prized for their blooms

• Cane: Cane Begonias have long stems with swollen nodes that resemble bamboo. They are grown for both their foliage and their flowers.

Are Begonia flowers edible?

Yes! The rumour is true, First Nations Peoples have been using Begonias in their plant medicines for thousands of years, and the leaves and flowers of some species are edible too. They have however adapted to produce high levels of oxalic acid to protect themselves from insects and herbivores, so please make sure to check that yours is edible before you nip out to the garden to forage a salad and consume your Begonia in moderation. 

Bright ideas for potted colour

If you’re always wondering what other uses you can put your plants to, oxalic acid is a mordant used to fix plant dyes, so there’s potential for your Begonias to yield even more joy and colour when you prune or uproot them at the end of the season.

In the hard to find Dyes from Plants of Australia and New Zealand (1971), Joyce Lloyd says scarlet Begonia flowers yield a bright pink when mordanted with alum. If you decide to experiment, remember to wear gloves, keep your dye pots separate from your food pots and work in well-ventilated spaces.

This rare Begonia likes to live dangerously, growing on steep, moist limestone cliffs in the semi-shade of a broadleaf forest near the mouth of Palawan's Puerto Princesa underground river. B. taraw was also found in a cave semi-shaded by tropical forest nearby. 

Although protected due to its location in a National Park, B. taraw is critically endangered and listed on the IUCN Vulnerable list due to the threat of rapid habitat loss in the Philippines.

B. taraw has fleshy, broadly ovate leaves and grows to 10cm. Its leaves are discolourous – mid-green on top and red underneath. 

Clusters of flowers in pink to white shades are arranged in cymes 50cm above the leaves with a central male flower and lateral female flowers up to 2cm in size with 3-winged ovaries. The female flowers branch up to six times, maturing successively, and there is a ring of fleshy hairs at the base of the flower's stem. The fruit of this tenacious Begonia is a 3-winged papery, pale brown capsule.

A single B. taraw specimen has been cultivated in Taiwan and flowered from summer to autumn. The plant was fruiting and flowering in November 2011 when the first specimens were collected.

The Palm-Leaf Begonia hails from the rainforests of south-eastern Brazil in Rio de Janeiro and Sao Paulo.

Like most tropical plants it is frost-tender and will thrive in an environment with consistent humidity and moist, fertile, well-drained soil. Found in the understory of rainforests, B. luxurians will be most likely to grow well if you have a spot with indirect sunlight or bright shade and some early morning sun.

A Begonia that is well suited to container gardening!

The Palm-leaf Begonia offers interesting foliage and fragrant flowers in spring and summer. Its shallow roots are ideal for pots or containers as long as you provide dappled light, constant moisture, good soil and drainage. It’s a great plant to integrate into your potted garden If you live in an apartment with a balcony or courtyard.

B. luxurians is one of the 'cane' Begonia varieties, and its height and shallow roots mean its stems will need staking to prevent them from snapping if they get too tall. Because of its height, it also benefits from an annual prune to remove any growth that looks leggy and unkempt.

B. luxurians leaflets are slender and serrated, creating palmate leaves up to 45cm wide. Stems are thick and visually akin to bamboo. They are discolourous with a green upper and a reddish-bronze underside which folds upward lengthwise.

The new leaves and stems of this decorative plant have a pink-red tinge, and the fragrant flowers are small, creamy-white with yellow stamens, growing in cymes above the foliage from late winter to summer.

Middle Gardens Beds 29 and 30 

Begonia x tuberhybrida cultivars are grown commercially in nurseries worldwide and only exist as the result of cross-breeding, which means there are no examples of them in the wild. Modern hybrid Tuberous begonias enjoy the shade and do not do well in areas prone to frost.

Tuberous Begonias are ideal hanging plants for bright places

These Begonias are grown for their vibrant, showy flowers, which bloom from summer to autumn, offering great value for the home gardener on a budget. They're most often used for seasonal bedding displays and potted colour in shady spots with dappled light and places that only get morning or late afternoon sun. 

They are frost-tender but don't despair if you're in a cool climate; they are also ideal as hanging plants and do well in indoor container gardens if they get at least four hours of indirect sunlight a day. Growing them indoors may reduce their flowering duration.

Growing begonias isn't hard, but there are a few things you can do to avoid common issues.

• Deadheading will prevent rotting flowers from causing disease.

• If your plant looks leggy, move it to a spot that gets more light. 

• If the leaves are turning brown and drying out, your green friend may be getting too much direct sun and needs to relocate to a spot with dappled light. 

The plant's flowers are waxy and come in shades of white, yellow, apricot, pink and red. Begonia x tuberhybrida's male blooms are the show stoppers; they're doubles and grow up to 15cm. Commercial growers will often remove the two female flowers that accompany the male, enabling the plant to put more of its energy into creating a dramatic display.

Unearth new forms propagating Tuberous Begonia seeds

Begonia x tuberhybrida has a winged seed capsule containing thousands of seeds that form behind the female flowers.

Because these are hybrid cultivars, their seeds may produce plants that vary from their parents, offering an exciting opportunity to grow new forms if you're a patient gardener who likes to experiment.

If you love your plant as it is and want more, true-to-type propagation is possible via tuber division or leaf cuttings. 

Although they are not on permanent display in the Garden, they are sometimes included in exhibition plantings in The Calyx. 

The wild ancestor of our modern Begonia rex cultivars was collected in Assam in the Himalayas. The plant is native to northeast India, the eastern Himalayas, southern China, northern Myanmar and Vietnam. It is found in rocky, moist, subtropical forested valleys and slopes with filtered light, high humidity and no frost.

Rex Begonia's hybrid descendants are now cultivated in nurseries worldwide. 

Rex Begonias are evergreen, rhizomatous perennials that grow to 50 cm. They are renowned for their variously patterned, veined, coloured and textured foliage, and their leaves can grow up to 30 cm. Stems are long, erect, succulent and hairy.

Although Rex Begonia varieties display clusters of small pale pink or white flowers in spring, summer or autumn, the vibrant leaves are the star of this show. The plants produce a dry, three-sided, winged seed capsule which contains seeds that look like rust. 

Gardeners can easily propagate from seed, however Rex Begonias  are crossbred, so their offspring may not be the same as the parent plant. If you want a true-to-type plant, your only option is clonal propagation by leaf cutting or rhizome sections.

Begonia ’ Black Magic’ is planted in Bed 29 in the Middle Garden, and other cultivars sometimes feature in displays at The Calyx. 

The native habitat of B. listada spans southern Brazil, Paraguay and northern Argentina.

It is found in the understorey of subtropical rainforests and enjoys filtered light, high humidity, and moist soil that is rich in nutrients.

B.listada or Begonia listada is a compact, bushy evergreen perennial that grows to 30cm tall. Its leaves have a bright green midrib and a deep red underside which is thought to reflect sunlight into the plant, assisting with photosynthesis. The contrast in foliage colour is enhanced when planted in acidic clay soil.

B. listada's leaves are elongated, asymmetrical, hairy and have the texture of velvet. It produces panicles of white flowers throughout the year in subtropical climates, but it needs bright, indirect or filtered light to put on a good show. 

The plant's fruit is a three-sided capsule containing an abundance of tiny seeds which can be propagated easily.

Plant in a semi-shaded location with soil enriched with welll composted organic material, protect from snails, especially when your plants are young and provide regular applications of slow release fertiliser.

Visit any of the following beds to see mass plantings: 

Bed 133a
Bed 30 
Bed 81 
Fer 

Buy a Begonia listada and support the Garden

You'll find the wild relatives  of the Semperflorens group growing in filtered light on forest floors in the moist subtropical rainforests of Argentina, Brazil, Paraguay and Uruguay in South America. 

The cultivars of the Semperflorens group grow in compact mounds to 30 cm tall. They have fibrous roots and soft, succulent stems, which makes them frost tender. The foliage is rounded and waxy and ranges from green to bronze.

Like the Tuberous Begonia, the flowers are the bedding Begonia's drawcard. They will bloom in loose clusters of single or double flowers in shades of red, pink and white with yellow stamens for most of the year if you live in a subtropical climate. The flowers are 1-2.5 cm across, the females have 4-5 petals with a three-winged ovary below, and the males have four petals, two narrow and two broad.

Given the right conditions, when the female flowers' winged capsule splits to disperse many tiny seeds, this Begonia will self-seed easily. They can become weedy if you live in Sydney, which has the perfect subtropical climate for self-seeding. 

Although they are often grown as annuals to bring a splash of potted colour to a mass planting, Begonia Semperflorens group are short-lived perennials. They are gregarious and do best planted in clusters. 

Their love of light shade and shallow roots make them ideal for plantings under trees because the trees' roots won't be interfered with; the trees will also protect them from frost if you live in a cooler climate. This combination of qualities makes Wax or Bedding Begonias an ideal plant for container gardening on balconies or patios. These delightful plants will also adapt to full sun in mild climates but need well-drained soil. 

 Top tips for transplanting Wax Begonias

Planting them a bit deeper in the soil than they were in their original container will trigger the newly buried stem to sprout additional roots which makes for a stronger, healthier plant.

Visit the Garden Explorer site to search for the  current location of Bedding Begonias.

B. Irene Nuss is frost tender and best suited to warm, sheltered spots, filtered light, sub-tropical humidity and moist soil.

Add texture and perfume to your container garden

B. Irene Nuss is a perennial, and the deep colour and texture of its foliage offers an ongoing source of delight. Cane Begonias are also known as Tree Begonias, and this cultivar has the potential to grow to 1.2m given ideal conditions, which will bring drama to your containers or pots. Its preference for filtered light and warm, protected positions serves apartment and balcony gardeners well.

Begonia ‘Irene Nuss’ is an evergreen, perennial with fibrous roots. It's a heavy feeder, so ensure you have fertile soil and regularly repot your plant if you're growing it in pots or containers.

Its leaves range from dark green to bronze and grow up to 20cm long. They are waxy with deep lobes, which led to their alternative moniker, Angel Wing Begonias. 

The flowers are mid-pink, with blooms growing up to 4cm on hanging panicles. They have the potential to bloom year-round in a subtropical climate, which means Sydneysiders get more bang for their buck with these stylish plants. 

The three-sided papery fruit capsule will split when dry, enabling the plant to self-seed. Because B. Irene Nuss is a hybrid If you want to grow another 'true-to-type' plant, you must propagate a clone from a cutting.

Grow cut flowers at home!

If you have designs on a cut flower garden, B. Irene Nuss is a must-have; its dark green to bronze leaves bring understated elegance to floral arrangements.

Take B. Irene Nuss home with you

If you love the look of 'Irene Nuss' and want to see it in your garden, visit the Growing Friends Nursery and pick up some plants. Your garden will look great, and your purchase supports the Gardens' scientific research.