Begonia care for shade, indoors and out

Begonia covers several very different plants, and they want the same three things: shade, even moisture and warmth. Say it beh-GO-nee-ah. This page sorts out which one you have, where it goes indoors or out, when to water it, and whether it comes back next year.

Shade or bright indirect light. Morning sun is survivable, afternoon sun burns the leaf.
Water when the top of the soil is dry, never on a fixed day.
Toxic to cats and dogs, and the underground part is the worst of it.

What kind of begonia you have, leaf or flower

Two things separate the plants sold under this name: whether you bought it for the leaf or for the flower, and what it grows from underground. The leaf kinds carry silver, purple or red markings and flower thinly. The flower kinds carry a long display over plain green leaves. NC State Extension counts more than 2,100 species in the genus, almost none of which reaches a shop, so any begonia plant you meet belongs to one of five commercial groups.

The test takes a minute and settles it. Feel the base of the stems, or tip the plant out of its pot and look at what the roots come off: a flat round tuber, a thick stem creeping along the soil surface, or plain fibrous roots with nothing swollen on them. A Prayer plant is the nearest comparison for foliage grown entirely for its markings, and it tells you what the leaf groups are for.

One plant sold as a begonia is not one. Strawberry begonia is Saxifraga stolonifera, a different family that happens to run the same kind of runners, and care advice written for a begonia does not apply to it. The plant care guide lists the other guides with the light and water each plant takes.

Wax, or fibrous. Small glossy leaves with a waxy surface and constant small flowers, sold in trays for bedding. Plain fibrous roots, nothing swollen.
Rhizomatous. A thick stem creeping along the soil surface with every leaf on its own stalk. Grown for the leaf, flowers held on thin stems above it.
Rex. A rhizomatous subgroup bred for colour, with an asymmetric leaf marked in silver, purple and red. It wants the most humid air of the five.
Cane. Upright bamboo-like stems with swollen joints, wing-shaped spotted leaves and hanging flower clusters. Angel wing and maculata are both cane begonias.
Tuberous. A flat round tuber at the base, the largest flowers of any group, and it dies back to that tuber every winter.

Do begonias like sun or shade?

Shade, with one qualifier that decides where the plant goes: morning sun is survivable and afternoon sun is not. University of Minnesota Extension says very few cultivars tolerate full sun and names the afternoon beam as the one to keep it out of.

Pay that range out both ways, because both ends have a sign you can read. In good light without direct sun the markings stay sharp and the soil dries faster, so you water more often. In deep shade the new leaves come in smaller, the colour drifts toward plain green, and the soil stays wet long enough to take the roots.

A scorched patch is dead tissue and never colours back in, so cut that leaf out rather than waiting on it to recover. If the brightest wall you have is still dim, low light houseplants covers what survives there.

Watering a begonia without rotting the roots

You water when the top of the soil is dry, not on a day of the week. Push a finger in to the first knuckle, and water only if it comes out dry.

Light and warmth set how fast that happens. The same plant in a bright room drinks faster than one in a dark corner, and faster in July than in January, which is why any fixed interval is wrong for most of the year. A Peace lily collapses within hours of running dry and stands back up the same evening. This one gives you no such warning, so you check the soil instead of waiting for a symptom.

The failure that kills it is rot at the base of the stem, and both extension sources put root rot first on this plant. It shows as a soft dark patch where the stem meets the soil, and by the time a leaf reacts the roots have already gone. Water the soil and not the leaves while you are there, because UMN names wet foliage as how the mildew starts.

Humidity, soil and feeding for a begonia

A peat-free houseplant mix with something coarse worked through it, humid air around the plant, and not much food. Rex begonias are the exception on humidity and want more of it than a living room usually holds.

The distinction that matters here is humid air against wet leaves. The plant wants the first and is damaged by the second, which is the opposite of what most people do with a spray bottle. A Maidenhair fern asks for the same humid air and shows a shortfall within days, where this one takes weeks to tell you.

The mix. Any peat-free houseplant compost with a handful of perlite or fine bark through it. What you are buying is water moving out of the pot rather than sitting in it.
Humid air, not a spray bottle. Stand the pot on a tray of damp gravel with the water level below the pot base, or group plants together. The RHS says misting is what brings on begonia mildew.
Feeding. A balanced liquid feed once a month while it is making new leaves, and nothing from autumn to spring. A kind grown for flowers takes a high-potassium feed instead of a balanced one.
Repotting. Up one pot size when roots show at the drainage hole, and no further. A pot too large holds water the plant cannot use, and that is where the rot starts.

Begonia flowers, and what a dropped bud means

It flowers in flushes rather than continuously, and the end of a flush is not the end of the plant. What restarts it is light and feeding. A plant moved somewhere brighter and given a high-potassium feed sets buds again, and one that is watered harder instead just sits wet.

Two different things make buds drop and they need opposite responses. A plant that has just come home from a shop drops buds because the light, the humidity and the temperature all changed at once, and it settles on its own if you hold the light and the water steady. A plant sitting wet or dark drops buds and keeps dropping, and nothing improves until you move it or let the soil dry out.

A red begonia, a pink begonia and a yellow begonia are all the same plant sold in different colours, with doubles in the tuberous and rieger groups. The rieger begonia is the one sold in full flower as a florist plant rather than for its leaf, and the RHS describes these hybrids as not intended for long-term cultivation and usually discarded after flowering, which is worth knowing before you plan to keep one. Angel wing flowers hang in clusters at the stem tips and stay on the plant, so they need no deadheading.

Do begonias come back every year?

It depends which one you have, and there are three cases. Most are tender and are either grown as annuals or brought indoors before the cold. Tuberous kinds can be lifted in autumn, dried and stored dormant, then started again in spring. A small number are hardy begonias that come back from the root, Begonia grandis among them.

The cold limit is the number to plan around, and two sources agree on it. NC State puts most cultivated begonias as intolerant of anything below 55°F, which is about 13°C, and the RHS gives 13°C as the winter minimum for the fibrous and rex kinds. That is a cool room rather than a frost, so a plant left on a balcony fails long before anything freezes.

What that gives you is a decision in September. If you want the foliage kinds next year, bring them indoors while the nights are still mild. If you want the tuberous ones, lift the tubers once the top growth dies back and keep them dry and frost-free. If you bought a tray of bedding begonias for one summer, treat them as one summer and take cuttings in late summer if you want more of the same plant.

Growing begonias in pots, in the ground and indoors

A pot suits most people, and the reason is control rather than looks. A pot moves out of the afternoon sun in July and comes indoors in October, and neither is possible once the plant is in the ground.

The ground case is a shade bed with soil that drains, and UMN asks for compost or sand worked into heavy soil before planting for exactly that reason. Indoors, the foliage groups are the ones that work all year: the rhizomatous and rex kinds hold their colour in a bright room set back from the window, and cane kinds grow tall enough to need a floor pot rather than a sill.

Trailing kinds belong in a hanging basket or on a shelf edge rather than in a bed, which is what weeping begonia and Begonia boliviensis are sold for. Choose the pot if you want to move the plant through the year, the ground if you have a shaded bed that drains and can treat the planting as one summer, and a basket if you bought a trailing kind.

Are begonias toxic to cats and dogs?

Yes. The ASPCA lists the genus as toxic to cats, dogs and horses, names soluble calcium oxalates as the toxic principle, and says the most toxic part is underground. That is the tuber or the rhizome, which is the part a dog digs at.

What the ASPCA lists in cats and dogs is vomiting and heavy salivation. Put the plant somewhere the animal does not go rather than relying on it to lose interest, and keep tubers off the floor while you are potting. If it has been chewed, call a vet or the ASPCA Poison Control line rather than waiting to see what happens.

A begonia on the wall

A rhizomatous or rex begonia suits a shallow pocket and a large cane one does not. The rhizome creeps sideways just under the surface, so those roots want a wide shallow space rather than a deep one. A cane begonia puts a metre of upright stem on a narrow base and goes top-heavy, which is a floor pot problem rather than a wall one.

The wall is usually the dimmest surface in the room, and that suits this plant where it would starve most flowering ones. A Pothos takes the pocket at any size if you want something beside it that asks for nothing.

The pocket holds 1.8 litres of substrate. The board hangs from one hinge on one wall hook, so the wall side is one screw, one plug and one drilled hole. Treat the filled weight like a heavy framed picture rather than a poster: plasterboard takes an expanding plug, brick a standard one, and a tiled wall needs a tile bit before the masonry bit. What each fixing actually holds once the substrate is wet is in hang plants without drilling.

Take a young rhizomatous or rex plant out of its pot.
Loosen the root ball with your fingers until it fits the pocket.
Sit it in, fill around it with substrate and press lightly.
Water slowly, in measured amounts, until the substrate is evenly damp.

Begonia problems and how to fix them

Almost everything that goes wrong here is either water at the root or air around the leaf, and the leaf tells you which. Yellowing that climbs from the bottom of the plant is the roots. A white bloom on the surface of a leaf is the air.

The two need opposite responses, which is why the distinction is worth making before you read the table. Wet roots mean the plant comes out of its pot today and the soft tissue gets cut away before it is repotted. Mildew means more air movement and less water on the leaves, and it spreads to whatever is standing next to it.

What you see	Why	The fix
Yellow lower leaves	Soil that has stayed wet, or roots already rotting	Stop watering, feel the stem base for soft tissue and repot if it gives.
White powdery film on the leaf	Begonia mildew, from still damp air or water on the foliage	Move air around it, stop misting and take the worst leaves off.
Brown crisp leaf edges	Dry air, or fertiliser salts building up in the pot	Raise the humidity around the pot and flush the soil with plain water.
Bleached pale patches that do not recover	Direct sun on the leaf	Move it out of the beam and cut the burnt leaves off.
Flower buds dropping	A recent move, or soil that is too wet or too dark	Hold light and water steady for three weeks before you change anything else.
Leggy stems with bare bases	Too little light, on a cane or wax kind	Move it brighter and cut the stems back to force branching lower down.

Begonia types: angel wing, rex, maculata and wax

Sort them by how much light the leaf needs, because that is what decides where in the house the plant can live. The marked and coloured forms lose their markings in the corner where the plain green ones are perfectly happy, so the prettiest one in the shop is the one that wants the best light in your room.

The angel wing carries the most weight of any name in this list, and the Chicago Botanic Garden describes it as a fibrous cane begonia with folded wing-shaped leaves, speckled or banded in several colours, and heavy hanging clusters of flowers. Past the table there is a long tail of collector begonia varieties, Begonia ferox, Begonia amphioxus and the escargot begonia among them, bought by people who already keep a few and sold on leaf texture rather than on flower.

Type	How to spot it	Light it wants	Fits a pocket?
Angel wing begonia	Upright canes with swollen joints, folded wing-shaped leaves, hanging flower clusters	Bright, no direct sun	Only while young
Begonia rex	Asymmetric leaf marked in silver, purple and red, on a creeping rhizome	Bright indirect, the most of any group	Yes
Begonia maculata, polka dot begonia, spotted begonia	One plant under three names. Silver-spotted olive leaf, red underside, cane stems	Bright, no direct sun	Only while young
Wax begonia, semperflorens	Small glossy waxy leaves, constant small flowers, sold in bedding trays	Shade to morning sun	Yes
Tuberous begonia	Flat round tuber at the base, the largest flowers, dies back every winter	Shade	No, it goes dormant
Rhizomatous, beefsteak begonia, Begonia masoniana	Thick stem creeping across the soil, grown for leaf texture rather than colour	Bright indirect	Yes
Dragon wing begonia, butterfly begonia	Cane-type hybrids bred for garden use, glossy leaf, heavy flowering	Shade to morning sun	No, too large

How to propagate a begonia from a leaf or a stem cutting

Which method works depends on which group you have, so settle that before you cut anything. The rhizomatous and rex kinds root from a leaf. The cane and wax kinds root from a stem cutting, because a cane leaf has no growing point to make a new plant from. Begonia seeds are how the breeders do it, and they are slow and unreliable at home, which is why the steps below cover the two methods that are not.

Take a newly matured leaf from a rex or rhizomatous plant, or a 7 to 10 cm stem tip from a cane or wax one.
For a leaf, cut through the major veins on the underside with a clean blade, about 2.5 cm apart.
For a stem cutting, strip the leaves off the lower half so nothing sits below the surface.
Lay the leaf face up on damp peat-free cutting compost and weight it so the cuts touch, or push the cutting into the same mix.
Cover with a clear bag or a propagator lid and keep it out of direct sun.
Pot each plantlet on once it has two or three leaves of its own.

Which group you have decides the method, and the one already on your windowsill is the one to start with. A rex leaf gives you several plants from one leaf, and a cane cutting gives you one plant that is already a stem tall.

Why are begonias hard to care for?

Because the name covers plants with different needs, so most people follow advice written for a group they do not own. A tuberous begonia wants a dormant winter and a rex wants humid air all year. The one mistake that kills across all of them is watering on a schedule instead of checking the soil.

Can a begonia take full sun at any time of year?

No, not as a rule. Weak morning sun is the one exception and UMN says so explicitly, while afternoon sun bleaches the leaf in patches that never colour back in. If the only window you have faces south, set the plant back from it rather than on the sill.

Is a strawberry begonia really a begonia?

No. It is Saxifraga stolonifera, in a different family, and it earned the name from the runners it throws rather than from any relationship. It wants cooler conditions and more light than a true begonia, so advice from this page does not transfer to it.

How do you keep a begonia blooming?

Light and feeding are the two levers. Move it somewhere brighter without direct sun, and switch to a high-potassium feed while it is in growth. Watering more does not bring buds back and it is the fastest way to lose the plant.

Can a begonia live in a bathroom with no window?

No. The humid air suits it and the light does not, and no plant makes food in the dark. A bathroom with a window is one of the better rooms in the house for one, and a windowless one is a place it slowly declines in.