Potted, spotted begonia

Polka dot begonia.

By Dorothy Dobbie

House plants have surged back into popularity during the year of COVID-19 with more varieties than ever now commonly available. One of my favourites is the polka dot begonia, Begonia maculatea ‘Wightii’. This is a cane of the cane varieties.

This is a difficult plant to grow indoors because indoor climates are often very dry, and this begonia needs lots of humidity. If it does not get enough humidity, the leaves become brittle and fall off. One idea is to run a diffuser nearby. This seems to keep it happy.

It likes damp, but not wet, soil. If the soil is too moist, the plant may develop root rot. Water from the top, not the bottom, and fertilize with a balanced feed at half strength every two weeks during the growing season. Let the water run through when you do water, then leave the plant until the top becomes dry. Try to avoid splashing the leaves. You do not need to deadhead but doing so will encourage the growth of additional stems.

Like all begonias, this plant is extremely sensitive to cold, so if you take it outside, and it is a good idea to do so, be sure to bring it in well before frost threatens. It does not like to be in temperatures below 15 degrees Celsius. Keep nighttime temperatures in mind before taking your baby outdoors for its summer holiday.

Place it in a well-shaded spot; it has little tolerance for direct sunlight. Indoors, polka dot begonia does not mind being away from direct light and will be quite happy out of the sun in a bright room. Sun scorch causes leaves to dry out and become brittle just as in the case of dry air; however, too little light and the leaves will fade and turn yellow.

Leaves are wing-shaped, covered in silvery polka dots on an olive or clear green field. The undersides of the leaves are a deep burgundy. It will reward with pale pink to almost white flowers up to three times a year.

The potting soil can be mixed with a bit of sand or additional perlite—it needs good drainage.

This is what happens when a leaf doesn’t get enough humidity.

Polka dot begonia can grow to four feet in length, so you will want to keep it pruned. The best time for pruning is in fall before bringing it back inside, which will encourage bushiness. Prunings can be easily rooted in water, provided they have at least two nodes.

Insects are less of threat than powdery mildew and fungal diseases which is why you will want to avoid wetting the leaves indoors. They are occasionally attacked by mealy bugs which look like bits of white fluff at stem junctions.

Begonia maculata can be toxic to pets, causing them to vomit or drool excessively.

This plant is well worth having for the indoor plant lover. It is not only a showstopper, it is a responsive plant that will reward you with flowers and a perky attitude when happy.

Polka dot plants need high humidity. Grouping plants near a diffuser keeps them very happy.