Watering, location, varieties & overwintering
Begonias are true beauties — but only if their roots aren’t left sitting in wet soil for too long.
The begonia is one of those plants people often pick up almost casually — and then it surprises them. Some varieties bloom for months, others look as if they were painted (Rex begonias), and others are simply perfect for the balcony. And yet, begonias end up on far too many windowsill plant graveyards far too quickly.
The reason is almost always the same: too much water, too little air around the roots, or a spot that may look bright but is actually too hot (south-facing window) or too dark (north-facing window). Once you know the basics, begonia care is honestly quite simple.
Quick profile: Begonia
Botanical: Begonia (Begoniaceae)
Origin: Tropics/subtropics (America, Asia, Africa)
Types: Flowering begonia, foliage begonia (Rex), tuberous begonia
Toxic? mildly irritating (especially tubers/sap), best kept out of reach of pets
Location: Bright, no intense midday sun
Watering: Moderate, allow the soil to dry slightly between waterings
Substrate: Loose, well-draining
Difficulty: easy to moderate (depending on the variety)
Which begonia variety do you have?
“Begonia” is a huge umbrella term. For proper care, it helps to roughly identify which type you have:
- Flowering begonias (e.g. Begonia semperflorens): Hardy, long-blooming, and perfect for balconies and bright windows.
- Rex begonias (foliage begonias): Loved for their leaves, they prefer even moisture and no hot direct sun.
- Tuberous begonias: Large flowers, love semi-shaded outdoor spots, and need a dormant period in autumn.
- Begonia maculata (“Polka Dot”): A very popular houseplant flower that loves bright, indirect light and consistent watering.
Begonia location
The best location is bright, but not scorching. A spot with morning or evening sun is ideal. Intense midday sun (especially behind glass) can burn the leaves — this shows up as dry, pale spots with brown edges.
If you keep it outside on the balcony: begonias prefer partial shade. Especially in Vienna, where balconies can heat up quickly in summer, a sheltered spot without direct midday sun is the best choice.
Quick check: Are the shoots becoming long and thin? Then the begonia is getting too little light. Are the leaves developing spots and drying out? Then it is often getting too much sun or the air is too dry.
Watering begonias
When it comes to watering begonias, the rule is: water regularly, but with care. Begonias do not like bone-dry soil, but they like being constantly wet even less.
- Water only when the top 2–3 cm of soil are dry.
- Always let excess water drain away (use a pot with a drainage hole).
- Water much less in winter because the plant grows more slowly.
Warning sign: Yellow, soft leaves and a “musty” smell from the pot are often a sign of too much water. In that case: water less, loosen the soil, check the pot (is the drainage hole clear?), and repot if needed.
Soil, pot & repotting
Begonias want a substrate that holds moisture without becoming waterlogged. A good flower potting soil with a little perlite, pumice, or coarse sand works beautifully. What matters most is proper drainage in the pot: a drainage hole + no standing water in the outer pot.
Repotting is worth it if:
- the soil is very compacted and water sits on top,
- roots are growing out of the bottom,
- the plant keeps looking limp despite proper care.
Fertilizing begonias
During the growing season (spring to late summer), one application of liquid fertilizer every two to three weeks is enough — at half strength. For flowering begonias, you can use a fertilizer for flowering plants; for foliage begonias, a balanced green plant fertilizer works well.
In winter: do not fertilize, or only very sparingly if the plant is still actively growing (e.g. by a very bright window).
Overwintering begonias
Many begonias are not frost-hardy. As soon as the nights turn cold, they need to come indoors. For balcony begonias, that means moving them to a bright spot before the first frost, watering less, and gradually letting the plant wind down.
Tuberous begonias have a true dormant period: the plant dies back, and only the tuber remains. Then store it dry and cool (not wet!) and restart growth in spring.
Propagating begonias
Begonias are surprisingly easy to propagate. The simplest methods are cuttings (for many varieties) or leaf cuttings (for Rex begonias): place a healthy leaf with its stem into loose substrate, keep it warm and bright, and maintain lightly even moisture — after a few weeks, new little plants will appear.
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Frequently asked questions about begonias
As soon as the top few centimeters of soil are dry. In summer, that may be every few days; in winter, much less often. The important thing is that no water sits in the pot.
Yellow leaves usually mean too much water or too little light. Brown, dry edges are often caused by air that is too dry, too much sun, or irregular watering. First check: pot drainage, location, and watering routine.
Yes, many varieties do very well outdoors — ideally in partial shade. Important: no frost. As soon as the nights turn cold, bring them inside or, in the case of tuberous begonias, start their dormant period.
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