Begonias pack more color into a shady corner than almost anything else you can plant, which is exactly why they’ve been a bedding and container staple for generations. The catch is that “begonia” covers a sprawling genus of roughly 1,500 species split across three completely different root systems, and the single biggest reason gardeners fail with them is applying one care routine to a plant that needs something else entirely. Drown a tuberous begonia by watering it like a wax begonia and it sheds its buds. Park a rex begonia in a sunny window that a wax type would love and its leaf patterns bleach out.
So the real skill in growing begonias is figuring out which one you have first, then giving that specific type what it wants. Get that right and they reward you with months of nonstop bloom or jaw-dropping foliage, indoors or out, with very little fuss. This guide walks through identification, then planting, light, water, feeding, overwintering, propagation, and troubleshooting, with the care that actually differs between types called out as you go.
Know your begonia type before you do anything
Every other decision flows from this one. Look at the roots, the leaves, and the flowers together and most begonias sort quickly into one of these groups:
- Wax begonias (also called fibrous-rooted or bedding begonias, Begonia semperflorens) are compact, rounded plants with small, glossy, waxy leaves in green or bronze and a steady supply of small red, pink, or white flowers. They come from a fibrous root ball with no tuber. These are the spring six-pack begonias sold by the flat.
- Tuberous begonias (Begonia tuberhybrida) grow from a fleshy, potato-like tuber and produce the showstoppers of the genus: large double blooms two to six inches across in pink, orange, red, yellow, and white, often on trailing stems made for hanging baskets. They die back completely each winter.
- Rhizomatous begonias, including the famous rex begonias (Begonia rex), spread by a thick horizontal stem at the soil surface and are grown almost entirely for dramatic foliage, with leaves in silver, burgundy, purple, and green. Their flowers are small and beside the point.
- Cane begonias, including angel wing types, grow upright on bamboo-like stems with segmented joints, carry speckled wing-shaped leaves, and dangle clusters of flowers. They range from tabletop houseplants to specimens five feet tall.
There are also a handful of hardy begonias, chiefly Begonia grandis, that survive winter in the ground in milder regions, and oddities like Begonia luxurians, the palm-leaf begonia, that can reach six feet. For most gardeners, though, the wax, tuberous, and rex groups cover the plants you’ll actually buy, and they want noticeably different things.
Where begonias grow best – light and placement
Begonias are tropical and subtropical understory plants, so most of them evolved under a forest canopy rather than in open sun. That heritage explains why partial shade or a spot with morning sun and afternoon shade is the safe default for nearly every type. Plant them where they get filtered light and good air circulation, which also helps fend off powdery mildew.
Light tolerance is one place the types diverge, and it’s worth knowing why. Wax begonias are the exception that can take real sun, but only certain ones: bronze-leaved varieties handle full sun far better than green-leaved ones because their leaves carry much more anthocyanin pigment, which works as a built-in sunscreen and antioxidant. Trials on heat-tolerant wax begonias have found those bronze types accumulate substantially more of that pigment under high light and even fold their leaves to cut the radiation hitting them. Green-leaved wax begonias lack both tricks, so give them morning sun and afternoon shade and save the full-sun beds for bronze selections like the Cocktail or Ambassador series.
Tuberous begonias are at the other end. They evolved in cool, cloudy Andean cloud forests, so direct afternoon sun bleaches their flowers and piles heat stress onto a plant that’s already unhappy when nights stay warm. Give them dappled light or gentle morning sun. Rex and other foliage begonias want bright indirect light only: an east-facing window or a spot set back from a south or west window. Too much direct sun fades the metallic leaf patterns that are the whole reason to grow them.
Soil and planting begonias outdoors
All begonias want the same basic soil: evenly moist, well-draining, and enriched with some organic matter, sitting around a slightly acidic pH of 5.5 to 6.5. In containers, reach for a quality all-purpose potting mix and make sure the pot has drainage holes, because soggy roots are the fastest way to lose a begonia. If your garden soil is heavy clay, work compost or coarse sand into the top eight to ten inches before planting. A quick test: pour water into a six-inch hole, and if it hasn’t drained within four hours, amend the site first.
Timing matters more than most people expect. Begonias are extremely frost tender, and even temperatures below 50 degrees can damage them, so wait to plant outdoors until all frost danger has passed and nighttime temperatures sit consistently at 50 degrees or warmer. Air temperature isn’t the whole story, either: planting into cold soil stunts wax begonias even when the air feels mild, so hold off until the soil reaches at least 60 degrees. Set wax begonia transplants about 6 to 12 inches apart and space larger types according to their mature size.
To plant, loosen the soil and dig a hole slightly wider and deeper than the root ball. Slip the plant out of its nursery pot, gently tease out the roots if it’s potbound, and set it so the base sits level with the surrounding soil. Backfill, tamp lightly to close air pockets, and water well, then keep the plant watered regularly until it’s established.
Tuberous begonias get a head start indoors. About 8 to 10 weeks before your last frost, set tubers concave (hollow) side up in a shallow tray of moist peat or potting mix, spaced an inch or so apart, and cover with about half an inch of mix. The growing point emerges from that hollow. Keep the soil at 65 to 68 degrees: below 65, sprouting stalls and rot creeps in. Sprouts appear in about three to four weeks, after which they move to bright light, and the plants go outside in May once soil hits 60 degrees and nights stay above 50.
Watering and feeding without killing them
The phrase to keep in mind is evenly moist, never soggy. Begonias like consistent moisture, but their roots rot in waterlogged soil, so let the top inch or two dry out between waterings. Always water at the base of the plant rather than overhead. Wet foliage invites powdery mildew and leaf spot, and on a hot day, water sitting on the leaves can scorch them. Drip irrigation or a morning watering at soil level is ideal. Wax begonias shrug off mild drought better than tuberous or rex types once established, so err on the dry side rather than the wet.
Feeding splits along a useful line: feed flowering types for blooms and foliage types for leaves. For wax and tuberous begonias, apply a balanced slow-release fertilizer at planting, then from early summer switch to a high-potassium feed such as a tomato fertilizer. The extra potassium supports sustained flowering by strengthening cell walls and helping the plant manage water during hot weather. Tuberous begonias in particular want a light hand: too much nitrogen early pushes leafy growth at the expense of flowers, and overfeeding at any point can trigger bud drop. Rex and other foliage begonias are the reverse. Grown for their leaves, they want a higher-nitrogen, water-soluble fertilizer at quarter strength every two to three weeks through the growing season, since full-strength feed burns their fine rhizomatous roots.
Caring for each type through the season
This is where generic advice falls apart, so here’s what each of the three main types actually needs once it’s growing.
Wax begonias are the low-maintenance workhorses. They bloom continuously from late spring to the first frost with little attention, and their flowers are largely self-cleaning, so deadheading is optional rather than required. A light pinch keeps plants bushy. They don’t go dormant, which means you can lift and overwinter them indoors as compact potted plants if you want to keep them going.
Tuberous begonias demand the most attention to temperature and water. They stop setting new blooms once soil temperatures climb above 80 degrees and sulk when summer nights stay above 70, so they shine in regions with cool nights and struggle through hot, humid mid-summers, where they may pause blooming entirely until things cool off. Their stems are brittle and their flowers heavy, so site them somewhere sheltered from wind, and stake the large-flowered types. The single most common complaint is bud drop, where formed buds fall before they open. It traces almost always to overwatering, dry air, or excess fertilizer: when roots sit in soggy soil, the lack of oxygen kills root tissue and the plant sheds developing buds to cut its losses. Water at the base, let the surface begin to dry between waterings, and ease off the fertilizer if buds start dropping.
Rex begonias and other rhizomatous types are grown for foliage, so the goal is steady, unstressed growth rather than flowers. Remove their small flowers if you’d rather the plant put energy into leaves. They grow actively between 65 and 75 degrees and slow down below 60. Because they spread sideways from a rhizome, they take well to shallow, wide containers, and they pair beautifully with other foliage in mixed shade plantings.
Growing begonias indoors as houseplants
Plenty of begonias make excellent houseplants, and rex types in particular are natural year-round indoor plants. The recurring indoor mistakes are overwatering and dry air. Let the soil dry slightly between waterings, and place the plant in bright filtered light near an east- or west-facing window, supplementing with a full-spectrum grow light for 10 to 12 hours a day if winter light is thin. Begonias also prefer to be slightly root-bound, so resist the urge to repot often; spring is the time to do it when you must.
Humidity is the make-or-break factor for rex begonias, which want ambient humidity in the 50 to 70 percent range. Most homes with forced-air heat run 20 to 30 percent in winter, well below that, and the first sign of trouble is brown, crispy leaf edges. Raise local humidity by setting the pot on a pebble tray filled with water to just below the gravel surface, by grouping houseplants together so their combined transpiration lifts the moisture around them, or by keeping the plant in a naturally humid bathroom or kitchen. One thing not to do is mist rex begonias directly: wet leaves invite the powdery mildew they’re especially prone to. For potting mix, an African violet blend or a light soilless mix with perlite drains far better than standard potting soil and suits their fine roots, and a shallow wide pot beats a deep one that traps water below the rhizome.
Overwintering begonias and storing tubers
In frost-free regions, roughly Zones 9 to 11, begonias can live outdoors year to year. Everywhere colder, they’re grown as annuals unless you overwinter them, and how you do that depends on the type.
Wax and other fibrous-rooted begonias can be brought inside before temperatures drop below 50 degrees and kept as houseplants in a bright window with raised humidity, or simply composted at season’s end if you’d rather start fresh. Acclimate them gradually, easing the light down as they move indoors and back up in spring, to avoid shocking them into dropping leaves.
Tuberous begonias go dormant on their own, and you store the tuber, not the plant. As late summer arrives, start reducing water and let the foliage yellow and the stems soften, which signals dormancy. After the first light frost, lift the plants, brush or wash the soil off the tubers, and cut the stems back to a couple of inches. Let the tubers cure in a dry, frost-free, ventilated spot for one to two weeks, then store them in peat moss, dry sand, or sawdust somewhere cool, ideally 45 to 60 degrees. Check them monthly through winter and toss any that show rot. In early spring, repot in fresh mix and start the cycle again, waiting for settled warm weather before they go back outside. Dusting cut surfaces with sulfur powder helps fend off storage rot.
Propagating begonias for free plants
Each type propagates by a different method, and using the wrong one wastes weeks. Stem cuttings work for wax and tuberous types: take a seven-to-ten-centimeter cutting that includes a leaf node and root it in water or moist perlite, where roots form in three to four weeks. Tuberous begonias also propagate by division, splitting a dormant tuber so each piece has at least one visible growth point, with sulfur dusted on the cuts.
Rex and rhizomatous begonias have the most satisfying trick. Take a mature leaf, cut it into pie-wedge sections each with a main vein running through the center, and press the sections vein-side down into moist propagation mix. Kept warm and humid, plantlets sprout from the cut vein in four to six weeks. You can also divide the rhizome itself into sections, each carrying a leaf or two and some roots, and pot them up in shallow containers. Wax begonias are the only group really worth growing from seed: surface-sow without covering, since the seeds need light to germinate, about 16 weeks before your last frost at 70 to 75 degrees.
Common begonia problems and how to fix them
Most begonia troubles come back to water, air, and humidity, and they’re easier to read once you know the signals. Powdery mildew, a white powdery coating on the leaves, is the classic begonia disease and thrives in still, crowded conditions. Space plants well, ventilate greenhouses, water at the base, and treat with neem or a horticultural oil if it appears. A soft brown stem base with wilting points to root or stem rot from overwatering: remove the affected stems, repot in fresh dry mix, and cut back on water. Mushy gray patches on leaves or flowers are botrytis blight, again a sign of poor airflow and excess moisture, and the fix is the same: clear the affected material and improve ventilation.
On the pest side, fine webbing and silvery stippling on leaf undersides mean spider mites, which love dry conditions, especially on rex begonias, so raise humidity and treat with insecticidal soap or neem. White cottony masses tucked into leaf joints are mealybugs, dabbed off with a cotton swab of rubbing alcohol. Distorted, stippled new growth can signal thrips, which also spread plant viruses, so remove badly affected plants and use yellow sticky traps. Vine weevil grubs can attack the roots of pot-grown begonias and are worth watching for when repotting.
One more thing worth knowing: begonias are toxic to dogs and cats. The underground parts, particularly tubers and rhizomes, contain calcium oxalate crystals and are the most poisonous, so keep plants out of reach of pets and children. They aren’t toxic to humans, though they can cause allergic skin reactions in some people. On the brighter side, begonias are deer resistant, which makes them a reliable choice where deer browse other bedding plants to the ground.
Begonia varieties worth growing
With thousands of cultivars to choose from, a few categories cover most needs. For sun-tolerant, low-maintenance bedding color, the bronze-leaved wax begonias and vigorous hybrids like the Surefire and Double Up series bloom nonstop from planting until frost and need no deadheading. For drama in hanging baskets and patio pots, large-flowered trailing tuberous begonias such as the Illumination and Double Delight series deliver fragrant, rose-like double blooms in warm pastels and bold brights. For foliage that earns its keep year-round indoors, rex begonias come in endless silver, plum, and chartreuse patterns, while angel wing and other cane types bring speckled leaves and dangling flower clusters on tall upright stems.
If you garden in a cold-winter region but want a begonia that comes back on its own, Begonia grandis, the hardy begonia, survives in Zones 6 to 9, growing 12 to 18 inches tall with heart-shaped leaves and clusters of light pink flowers from summer to frost before dying back and returning in late spring.
A quick word of caution on lookalikes: the so-called strawberry begonia, Saxifraga stolonifera, has similarly fuzzy green-and-silver variegated leaves but isn’t a true begonia at all. It spreads by runners like a strawberry plant, and its care needs differ, so check the botanical name before treating it like one.
Bringing it together
Match the plant to the spot and the care to the type, and begonias become one of the most rewarding things you can grow in shade, whether you want a wash of bedding color, a hanging basket dripping with double blooms, or a windowsill of patterned foliage. Start by identifying which type you have, give it the light, water, and feeding routine that suits it, and plan ahead for the first frost so the ones worth keeping make it to next season. Pick up a six-pack of wax begonias or a single tuber this spring and let the plant show you what it can do.