Description, History & Interesting Facts:

Begonias originally came from the tropical and subtropical moist climates of South and Central America, Africa, and southern Asia. The plants are monoecious. In other words, male and female flowers occur separately on the same plant.

There are hundreds of species and related cultivars within the Begonia genus. The Royal Horticultural Society has broken the genus into 7 main groups based on growth habit and cultivation needs.

‘Elatior’ Begonia Hybrids

Rieger begonias (Begonia × hiemalis), which are often called “Elatior” begonias, are in fact hybrids, originally created in 1883 from a cross between summer-flowering tuberous begonias (Begonia × tuberhybrida) and a rarely cultivated winter-flowering species, Begonia socotrana. Further hybridization with: Begonia veitchii, Begonia boliviensis and Begonia rosaeflora, resulted in the gorgeous Elatior hybrids we grow today.

Elatior begonias are native to, and thrive in tropical and subtropical climates where they are treated as perennials that flowers repeatedly. Outside the tropics they remain popular indoor pot plants, and are often grown as annuals in shady summer gardens.

The compact plants will grow around 30 to 40cm tall, producing fleshy, heart-shaped, green leaves, above which the spectacular richly coloured clusters of flowers appear. The flowers can be single or double and come in a wide range of colours from brilliant reds and oranges through to the gentler shades of yellow, pink, and shades of white.

Unless you are growing them in the tropics or subtropics, tuberous begonias are best treated as indoor pot plants or as summer annuals which are discarded when flowering has finished.

What to consider when buying Elatior begonias

Choose a vigorous and healthy looking plant that is compact and not too tall, as this is a sign of excessively rapid growth. Also check the plant for any signs of powdery mildew on the leaves before buying.

How to start begonia tubers indoors

If you are starting the tubers indoors, plant them in a shallow tray filled with moist palm peat, seedling or potting soil. Plant 2.5cm below the soil, and space them about 2.5cm. Place the tray in a dark room and water just enough to keep the soil moist.

Once the tubers begin to sprout, move them to an area with bright light. After the first two leaves have emerged and all danger of frost has passed, they can be transplanted straight into the garden, or into pots for indoor cultivation

The fibrous roots need good anchoring to support the heavy top growth, and a short stake, inserted when the plant is still small will support it while it grows and flowers.

For pot culture, a rich, well-drained potting mix with added perlite is perfect, though a specialist African Violet Mix is also good.

Begonia Elatiory Image by Jürgen Köditz from Pixabay 1How to care for ‘Elatior’ Begonias in the Home

Potted Begonia ‘Elatior’ hybrids are sold in full bloom throughout the year and look amazing as a coffee table centrepiece, or clustered together with tropical-looking leafy plants.

Remember, these plants are not fans of the extremes, and they thrive in a comfort zone between 15 to 26°C indoors, so if you’re comfortable in your home your begonia will also be happy.

They do best in medium to bright light indoors, and do not enjoy direct sunlight, which makes them perfect for many indoor spaces. Try to avoid drying air-conditioning if you can, as this dries the air.

Watering correctly is most important, and the soil should remain moist, but not soggy.  Allow the top 2 to 3cm of soil to dry out before watering again. Indoor pot plants should be watered from below in order to keep the foliage dry.

Although the plants do not like to stand in draughts, they do enjoy good air circulation around their leaves. Good ventilation and correct watering helps to prevent powdery mildew, leaf spot and the possibility of fungal diseases on the flowers.

Fertilise every week or two in summer with a balanced liquid fertiliser for flowering plants, diluted at half the recommended strength.

Begonia Elatior Image by Jürgen Köditz from PixabayHow to care for ‘Elatior’ begonias in the garden

It’s hard to beat tuberous begonias for bringing brilliant, long-lasting colour to shady summer gardens, and they can bloom continuously throughout summer and autumn, putting on a spectacular show in garden beds and borders, right up until the first nip of frost.

As container plants outdoors, tuberous begonias are second to none because of their long blooming season and lush foliage, so fill pots, hanging baskets and window boxes for a great show.

No matter whether you are transplanting only a few potted specimens into a pot, or mass planting the tubers in your favourite shady spot in the garden, Elatior begonias are sure to attract attention in the landscape.

When is the best time to plant begonias outdoors?

Begonias growing in pots can be transplanted into the garden once all danger of frost is over.

Begonia tubers can also be planted directly outdoors in spring, but to speed things up, you can start the tubers indoors about 8 to 12 weeks before the last frost date in your area so they have time to develop before being moved outside.

Once the weather warms up and night time temperatures are consistently above 10°C, the tubers can be transplanted into the garden. Like those grown indoors, they thrive in a comfort zone between 15 to 26°C outdoors.

These temperatures are also optimal over the winter because as tropical plants, these begonias are accustomed to consistent temperatures throughout the year. Therefore, if temperatures soar in midsummer, they may sulk a bit and stop flowering until the temperatures drop again in late summer and autumn. Check watering regularly during hot and dry spells to ensure they never dry out completely.

Remember, these plants are not fans of the extremes. They thrive in a comfort zone between 15 to 26°C. The perfect position would be in dappled sun or bright shade, and in a spot protected from strong winds which can damage the foliage and stems.

What soil type is best for begonias?

To avoid rotting of the tubers, begonias must be planted in well-drained soil.

In the garden, work in some compost or potting soil and other organic matter before planting to improve soil aeration and drainage. This is especially important if you have heavy or clay soil that drains poorly. If your soil is unsuitable it may be best to plant begonias into pots.

How to plant begonia tubers into garden beds

If you are planting tubers directly in the garden set each tuber round side down, about 2.5cm below the surface of the soil. To ensure good air circulation, space plants about 30 to 35cm apart in the garden. Stakes will be required to support the plants as they are abundant with foliage and flowers.

To jumpstart growth, pre-sprout the tubers before planting out. Read ‘How to start begonia tubers indoors’ above.

How to water begonias correctly

Watering correctly is most important in the care of begonias. The soil should remain moist, but not too wet.  Allow the top 2 to 3cm of soil to dry out before watering again.

Although the leaves of indoor plants should be kept dry, and drip irrigation works well to keep the foliage dry outdoors. Outside they will receive rainfall, and can be watered overhead, as the leaves and flowers will dry out much quicker than those growing inside.

If you are watering overhead, do so early in the day to give the foliage and flowers time to dry out before nightfall. This helps to prevent leaf spot and the possibility of fungal diseases on the flowers.

Fertilising Begonias

Fertilise every week or two in summer with a good liquid fertiliser for flowering plants, diluted at half the recommended strength.

Pruning:

Withered flowers should be removed regularly. This not only keeps the plant looking good but also prevents infestation with fungi.

If your begonia is tall and leggy, pruning can help it grow into a better shape. You can use your finger nails or a clean pair of scissors to prune away any old growth and shorten the top growth. The plant will respond by producing side shoots and grow into a fuller, bushier plant.

Repotting:

As its fibrous roots grow, the Elatior begonia will occasionally need to be re-potted to give it more room. Gently lift the plant out of its existing pot and place into a slightly larger pot and fill in with fresh potting soil and water well.

Begonia Elatior Image by Jürgen Köditz from PixabayPropagation:

Begonias, including Elatior begonias, are easily propagated from single leaf cuttings. While you can easily propagate begonias throughout the year, the best time to do so is in the spring, before they've hit their summer blooming season.

Select a healthy leaf for your cutting making sure it has a woody stem. Take a leaf cutting using a small, sharp knife or clean pair of pruning shears, and be careful to leave at least 2.5cm of the stem that connects the leaf to the rest of the plant. Nick a vein on the back of the leaf and press the stem into soil until the leaf lies on the damp soil to root.

Cover the newly planted cutting with a plastic bag to create a humid environment and place in a well-lit and warm spot.

Mist the cutting every few days, or as required, and within six to eight weeks, your Elatior begonias will have developed roots and be ready to be planted out.

Even a fleshy stem placed in a glass of water will root, or you can dip it in hormone rooting powder or gel and insert into moist, palm peat or potting mix.

Problems, Pests & Diseases:

If your Begonia is stretching out like it's trying to escape its pot, it's likely too hot. If it looks like it's hugging itself, curling inwards, it's probably too cold.

Similar to other houseplants, Elatior begonias can become afflicted by various pests, including: Aphids, caterpillars, spider mites, thrips, and whiteflies. Apply neem oil or insecticidal soap to get rid of pesky insects.

Diseases to watch out for include botrytis, fusarium, powdery mildew, and rhizoctonia. The best way to prevent these is to ensure adequate ventilation and correct watering.