Rieger begonia

Rieger begonia: how do you recognise it?

Habit

Compact, bushy plant 25–35 cm tall and as wide, with fleshy stems.

Leaves

Lopsided heart shape, glossy mid to dark green, with a scalloped edge.

Flower

Single, semi-double or double, 3–5 cm across, in small clusters above the leaves.

Colour

Red, pink, orange, yellow, salmon and white, sometimes two-toned.

Roots

Fine, fibrous roots that rot quickly in wet compost.

Flowering: October–March · Plants: March–April · Pruning: March–April

Why grow it?

• Flowers for months in the darkest part of the year, from October to March.
• A wide choice of warm and fresh colours, single or double like little roses.
• Compact and ideal for a windowsill, table or desk.
• In summer it also looks good on a sheltered patio or balcony in light shade.
• A colourful gift that lasts a long time with good care.

Rieger begonia: where does it grow best?

• Bright, but out of strong midday sun: an east or west window is ideal.
• Room temperature of 15–20 °C; in a cooler room it flowers for longer.
• Not in a draught and not above a radiator: warm, dry air shortens flowering.
• Open, humus-rich compost that drains well.
• From late May to September it can go outside in a sheltered spot out of strong sun.

Light

Bright, out of direct sun

Potting soil

Multi-purpose compost or airy, humus-rich compost

Acidity

Acid or neutral

Watering

Moderately

Size

0.35 m tall, 0.35 m wide

Temperature

Minimum 12 °C

Goes well with

• Cyclamen: Also flowers in winter and likes the same cool, bright spot.
• Asparagus fern: Fine foliage as an airy backdrop for the colourful flowers.
• Poinsettia: Together they make a festive winter table.
• Ivy: Trailing green in a mixed bowl.

Rieger begonia: when and how to plant it?

Plant in March–April.

1. A newly bought plant usually does not need repotting straight away; repot in March or April, when it starts growing again after flowering.
2. Choose a pot only slightly larger, with a drainage hole.
3. Use open compost for flowering plants, if you like with a little perlite mixed in.
4. Set the plant at the same depth as before, no deeper: the base of the stems rots easily.
5. Water moderately and let the excess drain away; then give it a permanent, bright spot.

Care

Water

Water as soon as the top centimetre is dry, onto the compost or from below, never over the leaves and flowers. Empty the saucer after a quarter of an hour.

Feeding

During flowering, liquid feed for flowering plants at half strength every two weeks.

Deadheading

Remove faded flowers and yellow leaves straight away: it keeps flowering and grey mould gets no chance.

Humidity

Moderately humid air is ideal, but do not spray the leaves: that leads to mildew and spots.

After flowering

Cut back, water a little less and keep it bright. It often regrows, although it rarely flowers as freely as in the first year.

Tip: Buy a plant with lots of buds and only a few open flowers: it will flower for longest. Keep it cool and bright, water without letting it stand wet and remove every faded flower.

Rieger begonia: when to prune it?

Pruning months: March–April.

When: Remove faded flowers throughout the flowering period. After flowering, in March–April, you can cut the plant back.

How:

• Snip off faded flowers with their stalk, as close to the leaves as possible.
• After flowering, cut all stems back to 8–10 cm, just above a leaf.
• Remove yellow and rotten leaves straight away.

Caution: Use a clean, sharp knife or scissors: ragged wounds rot quickly.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Tip cuttings

In spring, take 8–10 cm cuttings from non-flowering shoots, remove the lower leaves and insert them in moist cutting compost under plastic at about 20 °C. They root in 3–4 weeks.

Rieger begonia: how does it get through the winter?

• A house plant that flowers in winter: give it the brightest spot, out of direct sun.
• Minimum 12 °C; at 15–18 °C it flowers for longest.
• Keep it away from radiators, open windows and cold draughts.
• If it has spent the summer outside, bring it in during September, before nights drop below 12 °C.

Diseases and pests

• Grey mould: Grey, fluffy mould on flowers and leaves, especially in cool, damp air. Remove faded flowers and affected parts at once, do not water over the plant and allow some air movement.
• Powdery mildew: White powder on the leaves. Cut off affected leaves, give the plant more space and a cooler spot, and do not mist it.
• Root rot: The plant wilts although the compost is wet. Water less and never leave water in the saucer; replace a badly affected plant.
• Aphids and whitefly: Small green aphids or tiny white flies under the leaves. Rinse with lukewarm water or hang up a yellow sticky trap.
• Bud drop: Caused by draughts, a spot that is too warm, dry compost or frequent moving. Give it a permanent, cool and bright place.

Through the year

• January: Flowering. Keep it away from the radiator.
• February: Flowering. Check for grey mould and mildew.
• March: End of flowering. Cut back to 8–10 cm.
• April: Repot in fresh compost. Take tip cuttings.
• May: From late May possibly outside in light shade.
• June: Water moderately. Feed every two weeks.
• September: Bring it back in before cold nights.
• October: Start of flowering. Bright spot, out of strong sun.
• November: Flowering. Feed every two weeks.
• December: Flowering. Remove faded flowers.

Edible and useful

Not edible. All begonias are poisonous, especially the tubers and roots: they contain oxalates which, when chewed, cause a burning feeling and irritation of the mouth and throat, with drooling and vomiting, in children as well as in cats and dogs; grazing animals and rabbits can fall ill from them too. Tuberous begonias overwinter dry in a box or pot: store the tubers out of reach of children and pets, and not with the potatoes. Indoor begonias often stand on the windowsill, at a child’s height and within a cat’s reach: put them higher up or in another room. The flowers of tuberous begonia sometimes appear on lists of edible flowers, but because of the oxalates they are best not eaten, especially if you have kidney stones. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Did you know?

• The name hiemalis means ‘of winter’, because it naturally flowers in winter.
• It flowers when the days are short. Growers control flowering with blackout and extra lighting, so it is sold in flower all year round.
• One of its parents, Begonia socotrana, grows in the wild only on the island of Socotra in the Arabian Sea.