How to Grow Begonias

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How to grow begonias depends first on the type you have, because wax, tuberous, rex and hybrid begonias need different light, water and winter care. Across the types, the basic pattern is partial shade for most, moist soil that drains well, light feeding, and roots that never sit in water. This guide follows two Clemson University factsheets and one University of Florida publication, and it marks the points those pages leave open.

Quick answer

Most begonias grow well in partial shade, in moist, well-drained soil with plenty of organic matter.
Feed lightly. Clemson says most begonias are not heavy feeders.
Tuberous begonias must be dug up before the first frost and stored dry over winter.
Keep roots out of standing water, because overwatering will easily cause root rot in rex begonias.

Pick the begonia type first

Clemson names wax begonias and tuberous begonias as the most common begonias in southern landscapes, and it adds other groups for specialty uses. Wax begonias are the bedding type most gardeners know. Tuberous begonias grow from tubers and have flowers two to four inches wide. Rex begonias are grown mainly for their leaves. The hardy begonia is a perennial that survives winter in South Carolina, while most other begonias do not.

Within the hybrids, the choice depends on the job. The Clemson page describes the Dragon Wing series as one that will “consistently flower from spring until frost without pause.” The Non-stop series is more heat-tolerant than other tuberous begonias, and Clemson says that type is best suited to growing in the South. Angel wing begonias, also called cane begonias, can be grown as houseplants or outdoors in partial shade during the summer.

Wax begonias are the most forgiving group. The factsheet says they “withstand drought and heat better than other begonias, although they prefer moist, well-drained, fertile soil.” Their light needs are wider than the others. Those with bronze foliage “do better in the sun than green varieties”, so the leaf color is a useful guide when you pick a planting spot.

Give the right light

Light is the first thing to get right. The Clemson factsheet puts the rule this way: “In general, begonias need bright light to flower well; however, some will burn if the light is too intense.” A plant in deep shade may flower poorly, and a plant in hard sun may scorch. That is why partial shade is the default for most types, with the exceptions described above.

Tuberous begonias fit the same pattern. Clemson says they “grow best in partial shade”, and it advises care at the start: “Keep out of direct sunlight.” In practice, the tubers go into shallow trays in early spring, away from direct sun. Once frost is past, the young plants move outdoors to a partially shaded spot.

Rex begonias are a different case. The UF/IFAS guide says they “do well in bright, indirect light”, and it warns that “Foliage of these plants could burn when plants are exposed to excessive direct sunlight.” For most rex varieties it gives a light level of “1,500 to 2,200 foot-candles”, and it notes that rex begonias need 14 hours of day length to keep growing. A home grower cannot read foot-candles without a meter, so treat that number as a reference for an indoor setup rather than a setting to copy.

For plants kept indoors, the Clemson indoor factsheet says that “Flowering houseplant begonias should be located in a bright spot and receive some direct sunlight.” Its example is “Early morning sun in an east window works well.” Clemson also says many cane and shrub types flower best with some direct sun, and that several hours of winter sun help. The same guide warns that some begonias do not tolerate direct sunlight and should be placed in the shade. Match the plant to the spot, not the other way round.

Soil, water and feeding

Soil and water cause more trouble than light for most begonias. Clemson says most begonias grow well in “moist, well-drained soil containing plenty of organic matter.” For indoor plants the advice is more exact: “Keep soil evenly moist, allowing it to dry only slightly between waterings.” The same guide adds that “Always avoid wet or waterlogged soil.”

A saucer can undo good watering. The indoor factsheet states: “Never allow plants to sit in a saucer of water.” Empty the saucer after watering so the pot does not stand in it.

Water less in the cool months. The indoor factsheet says: “Reduce water in winter (stop watering tuberous begonias in fall).” For tuberous types, that means watering stops in fall. Rex begonias need a different balance, since they “prefer a very humid environment” but overwatering “will easily cause root rot.” More humidity and more water are not the same thing, and the rex guide points to drainage as the safeguard.

Tuberous begonias need a careful balance of their own. Clemson says: “The plants need frequent watering and light fertilization, but an excess of either causes flower bud drop.” Frequent watering is not a license to soak the pot, and feeding should stay light.

Most begonias are not heavy feeders. Clemson suggests a complete slow-release fertilizer for annual flowers, applied according to the package. Indoors, the guide ties feeding to growth: “When plant is in full growth, fertilize with balanced liquid fertilizer at half strength at alternate waterings.” The rex guide suggests a foliage feed every month.

Planting and propagation

For wax begonias in the garden, Clemson says: “Set plants 6 to 8 inches apart in the garden after the danger of frost is past.” The same factsheet also gives 12 inches as the spacing for bedding varieties, so the two figures disagree. The page does not say which to use for a given cultivar, so check the plant tag. Clemson adds that begonias “look best when used in mass”, which argues for grouping plants rather than setting single specimens.

Wax begonias can also start from seed. Clemson says to “Sow the tiny, dust-like seed indoors, on top of the growing medium, without covering, at 68 to 75° F.” It says to “Start seed about 12 weeks before planting outdoors.” Tuberous begonias take longer from seed. The factsheet says they “should be started from seed as much as 14 to 16 weeks before they will be ready to be planted out in the landscape.”

Cuttings are another route. Clemson says: “Plants may also be started indoors from stem cuttings taken in the spring or fall.” For rex begonias, the UF/IFAS guide lists three methods: “Rex-cultorum begonias can be propagated in three ways, based on their type: by softwood cuttings, by leaf cuttings, or by dividing the rhizomes in summer.” The guide adds that leaf cuttings can work because rex begonias can regenerate from almost any plant part.

Overwinter tubers and cut back old plants

Tuberous begonias do not survive a cold winter in the ground. Clemson says: “Tuberous begonias must be dug up and replanted each year because they will not survive the winter cold.” The steps come in order. First, “Dig tubers before the first frost.” Second, “Cut tops back to within a couple of inches of the tubers.” Third, after the tubers dry, pack them “in cardboard boxes between layers of vermiculite, peat moss, or wood shavings” and store them at 45 to 55° F.

The indoor factsheet describes the same task from a different angle. At the end of the flowering season, it says, “stop watering and cut off shoots.” Then “Lift tubers from the soil and store in dry peat moss in a cool, dry place.” It adds that “Tubers can be saved over winter and replanted in spring.” The two pages name different packing materials, but both agree on dry and cool storage.

Lorraine and Elatior begonias are a winter-flowering group, and the indoor factsheet gives them their own rules. It says they “are usually discarded after flowering but can be restarted by cutting them back to within 3 inches of the crown.” It also says: “Reduce water and keep in a cool location. Increase water in spring.” Pinching helps the young plant branch, because the factsheet says to “Pinch out the tips when the plant is young to promote bushier growth.”

Containers suit many begonias. Clemson says they “can be used as bedding plants and in window boxes, hanging baskets, and other containers.” Tuberous types with trailing stems, which the Clemson page says reach “12 to 18 inches long”, are a good fit for hanging baskets. For a balcony, see our balcony planters guide, and for a window box, see self-watering window box planters.

Common problems and warning signs

Clemson lists the disease problems: “Disease problems associated with begonias include Botrytis blight and stem rot, powdery mildew, and Pythium root and stem rot.” It also names the common pests: “The major pests of begonias are mealy bugs, spider mites, thrips, scales, snails, and slugs.” Those are the groups to look for. This guide does not add treatment advice.

The UF/IFAS rex guide describes the fungal pattern in more detail. It says: “Major adversaries to rex-cultorum are botrytis and powdery mildew.” The same guide notes that “These fungal diseases are characterized by white spores on the leaves”. Its prevention advice is cultural: “The best way to prevent these is to remove dead leaves quickly and ensure good air circulation reaches the plant.”

Overwatering is the other warning sign. For rex begonias the guide is blunt, saying overwatering “will easily cause root rot.” A pot or bed that stays wet for long periods is the first thing to check.

Seasonal timing and cold

Most begonias are tender. The indoor factsheet says that begonias are “grown either as annuals or dug up in the fall, stored and replanted in the spring”, with the hardy begonia as the exception. That single sentence describes two routes: treat the plant as an annual, or lift it and keep it through winter.

For rex begonias, the UF/IFAS guide gives a different scale. It lists USDA hardiness zones 7 to 12 for the type and gives 72 to 80 degrees Fahrenheit as the best daytime range, with 60 to 65 degrees at night. The guide says that “Generally, rex begonia plants prefer relatively cool temperatures”. Some varieties, it adds, “can handle temperatures as low as 50°F or as high as 90°F.”

Mistakes to avoid

Standing a pot in a saucer of water, which the indoor factsheet says never to allow.
Feeding heavily. Clemson’s guidance for most begonias is a complete slow-release fertilizer, applied as the package says.
Leaving tubers in the ground past the first frost, when Clemson says to dig them before the frost arrives.
Leaving dead leaves on the plant, where the rex guide says to remove them quickly.

How we chose

This guide draws on three publications: the Clemson University HGIC factsheet on begonias, the Clemson HGIC factsheet on growing begonias indoors, and the University of Florida IFAS publication on rex begonias. We opened each one on 2026-10-23 and read its text. We kept statements that a page makes in plain words, and we checked every quoted sentence against the text of the page it came from. Where a page covers only one group, such as rex begonias, we say so. None of the three pages names a product to buy, so this guide does not name one either.

What we could not verify

The three pages do not give one watering schedule in days, so the water advice here is a matter of soil condition rather than a calendar. They also do not give exact in-ground spacing for tuberous or rex begonias, and the two spacing figures for bedding plants in the Clemson material differ, as noted above. Lorraine and Elatior begonias get only a short passage. This guide does not compare cultivars for bloom length or color, and it does not rank varieties.

What the sources do not say

The sources do not give a frost date, a tuber size, or a storage length in months. The two Clemson pages describe conditions in South Carolina, and the rex guide comes from a University of Florida publication, so the calendar in your own region may differ. The sources also do not say how long a dormant tuber can stay in storage before it should be checked. Your county extension office can fill those gaps for your area.

Frequently asked questions

Can begonias grow in full sun?

Some can. Clemson says: “These begonias are not restricted to partial shade; they can be grown in full sun as well.” That refers to wax begonias, and bronze-leaved wax begonias do better in sun than green ones. Tuberous begonias grow best in partial shade, and the rex guide warns that foliage can burn in strong direct sun.

Do begonias need to come indoors for winter?

It depends on the type. Clemson says tuberous begonias “must be dug up and replanted each year because they will not survive the winter cold.” The indoor factsheet says wax begonias “can be dug up and potted in autumn and brought indoors for the winter.” The hardy begonia is the exception, and the indoor factsheet says it “will survive winters in South Carolina”.

How often should begonias be watered?

The sources do not give a number of days. The indoor factsheet says to keep the soil “evenly moist, allowing it to dry only slightly between waterings.” Cut back in winter, and never let the pot sit in a saucer. The right schedule keeps the soil moist without making it wet.

Why do begonia leaves get white spores?

The UF/IFAS rex guide describes fungal diseases “characterized by white spores on the leaves”, and names botrytis and powdery mildew as the main ones. Clemson lists powdery mildew among the disease problems of begonias. The prevention step in the rex guide is to “remove dead leaves quickly and ensure good air circulation reaches the plant.” This guide does not recommend a treatment, so ask your local extension office about options for your area.

Can begonias be grown indoors?

Yes. The indoor factsheet says flowering houseplant begonias “should be located in a bright spot and receive some direct sunlight.” It recommends an east window for early morning sun, and it says that “Begonias growing indoors should be moved to a partly sunny location outdoors during the summer.” Keep the soil evenly moist, and do not let the pot stand in a saucer.

Sources

https://hgic.clemson.edu/factsheet/begonia/ (opened 2026-10-23)
https://hgic.clemson.edu/factsheet/growing-begonias-indoors/ (opened 2026-10-23)
https://journals.flvc.org/edis/article/download/131685/136498/241327 (opened 2026-10-23)