How to Grow Begonias: Complete Care Guide for Every Type

How to Grow Begonias: Complete Care Guide for Every Type

Begonias are the answer to every gardener's biggest challenge: what do I plant in the shade? While most flowering plants demand full sun, begonias thrive in the dappled light under trees, on shaded porches, and in north-facing windows. With over 1,800 species and thousands of cultivars, there is a begonia for every growing situation — from the humble wax begonia edging a shady walkway to the jaw-dropping rex begonia with leaves that look like living abstract art.

What makes begonias truly special is their versatility. They work as bedding plants, hanging basket stars, indoor houseplants, and collectors' showpieces. This guide covers the four main groups so you can choose the right begonia and give it exactly what it needs.

Quick Facts

Types of Begonias: Choosing the Right One

Wax Begonias (Begonia semperflorens)

The easiest and most popular begonias. Compact, mounding plants with waxy, rounded leaves (green or bronze) and clusters of small flowers that bloom nonstop from planting until frost. They are the workhorses of shade gardening — tough, drought-tolerant once established, and virtually pest-free.

Best for: Shade garden beds, borders, edging, containers, mass planting. Best varieties: Ambassador (compact, heat-tolerant), Cocktail (bronze leaf), Big (extra-large flowers), Sprint Plus (early blooming).

Tuberous Begonias (Begonia x tuberhybrida)

The showstoppers. Tuberous begonias produce the largest, most spectacular flowers of any begonia — up to 6 inches across in forms that resemble roses, camellias, and carnations. They grow from tubers (like bulbs) and go dormant in winter. They prefer cool temperatures and struggle in hot, humid climates.

Best for: Hanging baskets, shaded containers, cool-climate patios, summer displays. Best varieties: Nonstop (compact, heavy blooming), Illumination (trailing for baskets), Picotee (ruffled bicolor edges), On Top (upright doubles).

Rex Begonias (Begonia rex-cultorum)

Grown for their extraordinary foliage rather than flowers. Rex begonia leaves come in stunning combinations of silver, purple, pink, red, green, and black, often with metallic sheens, spiral patterns, and dramatic veining. They are primarily houseplants.

Best for: Indoor growing, terrariums, shaded patios (summer only), collectors. Best varieties: Escargot (spiral silver leaves), Fireworks (silver and purple), Iron Cross (distinctive cross pattern), Jurassic (massive ruffled leaves).

Angel Wing Begonias (Begonia coccinea hybrids)

Tall, cane-stemmed begonias with wing-shaped leaves often spotted with silver dots. They produce hanging clusters of flowers and can grow 3-5 feet tall. Excellent houseplants or shade garden specimens.

Best for: Indoor growing, shaded patios, conservatories, tall container focal points. Best varieties: Dragon Wing (heat-tolerant, trailing), Lucerna (classic spotted leaves), Sophie Cecile (pink spots), Benigo Pink.

Rieger Begonias (Begonia x hiemalis)

Hybrid begonias bred for indoor blooming during winter. They produce masses of rose-like double flowers in bright colors. Treat as seasonal houseplants — they rarely rebloom well after the first display.

What You Will Need

• Begonia plants, tubers, or cuttings (nursery transplants are easiest)
• Quality potting mix with perlite for drainage (or mix your own: 2 parts peat, 1 part perlite, 1 part compost)
• Containers with drainage holes
• Slow-release fertilizer (like Osmocote) or balanced liquid fertilizer
• Mulch for garden bed plantings
• Humidity tray (for rex begonias indoors)
• Pruning shears for grooming

Step-by-Step Growing Guide

1. When to Plant

Outdoors: Plant after all danger of frost has passed and nighttime temperatures are consistently above 50°F. In most zones, this means late May to early June.

Tuberous begonias from tubers: Start indoors 8-10 weeks before the last frost date. Place tubers hollow-side up in shallow trays of moist potting mix at 65-70°F. Once sprouts are 2-3 inches tall, transplant to containers or garden beds.

Indoors (rex, angel wing): Any time of year. Avoid repotting during winter dormancy.

2. Light Requirements

This is where begonias differ most from other flowering plants:

The rule: Most begonias prefer bright shade or filtered light. Direct afternoon sun scorches leaves and fades flowers. Morning sun with afternoon shade is ideal for outdoor types. Indoor types want a bright north or east window.

3. Soil and Planting

Begonias need rich, well-draining, slightly acidic soil (pH 5.5-6.5). They are fussier about drainage than most plants — waterlogged roots rot quickly.

For containers (all types):

• Use a premium peat-based potting mix
• Add 20-30% perlite for extra drainage
• Ensure pots have drainage holes — no exceptions
• Do not use garden soil in containers

For garden beds (wax begonias):

• Work 2-3 inches of compost into the top 8 inches of soil
• Space 8-12 inches apart (closer for mass effect, wider for airflow)
• Plant at the same depth as the nursery pot — never bury the stem deeper
• Mulch lightly (1-2 inches) to retain moisture, keeping mulch away from stems

For tuberous begonias in containers:

• Plant tubers hollow-side up, barely covered with soil (1/2 inch)
• One tuber per 6-inch pot, or three per 12-inch hanging basket
• Keep soil barely moist until sprouts appear, then increase watering

4. Watering — The Critical Skill

Watering is the number one factor in begonia success or failure. The golden rule: keep soil consistently moist but never soggy.

• Check before watering: Let the top 1 inch of soil dry before watering again
• Water at the base, never overhead — wet foliage causes powdery mildew and botrytis
• Morning watering is best — gives any splashed foliage time to dry
• Containers: May need daily watering in summer heat
• Rex begonias indoors: Water when top inch is dry. They prefer slightly drier conditions than other begonias
• Tuberous begonias: Most sensitive to overwatering. Excellent drainage is critical.

Signs of overwatering: Mushy stems, yellowing leaves from the base up, stem rot. Signs of underwatering: Crispy leaf edges, wilting, flower drop.

5. Fertilizing

Begonias are moderate feeders that respond well to regular light feeding.

• Slow-release granules at planting time (lasts 3-4 months)
• OR liquid fertilizer (balanced 20-20-20 or bloom-boosting 15-30-15) every 2 weeks during active growth
• Rex begonias: Feed monthly at half strength — they are light feeders
• Tuberous begonias: Feed every 2 weeks with high-potassium fertilizer for bigger blooms
• Stop fertilizing when growth slows in fall (or when preparing tuberous types for dormancy)

6. Humidity

Begonias are tropical plants that appreciate humidity, especially indoors.

• Rex begonias need 50%+ humidity — use a humidity tray (pebbles + water under the pot), group plants together, or run a humidifier
• Wax begonias are the most humidity-tolerant and adapt to normal indoor conditions
• Do NOT mist begonia leaves — water droplets on foliage promote fungal disease. Increase ambient humidity instead.

Overwintering Begonias

Wax Begonias

Take cuttings in September, root in water or perlite, and grow on a bright windowsill all winter. Or dig up entire plants, pot them, and bring indoors as houseplants.

Tuberous Begonias

1. After the first light frost blackens the foliage, cut stems to 2 inches
2. Dig up the tubers carefully
3. Let them cure in a warm, dry place for 1-2 weeks until stems detach easily
4. Store tubers in dry peat moss or vermiculite at 45-55°F (an unheated basement or garage)
5. Check monthly — discard any that feel soft or show mold
6. Restart indoors 8-10 weeks before spring planting

Rex and Angel Wing Begonias

Already houseplants — just reduce watering and stop fertilizing during winter. Keep in bright indirect light. Growth slows but they stay evergreen.

Propagation

Begonias are among the easiest plants to propagate.

Stem Cuttings (Wax, Angel Wing)

1. Cut a 4-6 inch stem tip with 2-3 leaf nodes
2. Remove lower leaves
3. Place in water or moist perlite
4. Roots form in 2-3 weeks
5. Pot up when roots are 1-2 inches long

Leaf Cuttings (Rex Begonias)

1. Cut a healthy leaf with 1-2 inches of stem attached
2. Insert the stem into moist perlite or seed-starting mix
3. Cover with a clear plastic bag or dome to maintain humidity
4. Small plantlets emerge from the base in 4-6 weeks
5. Alternatively, lay a leaf flat on moist mix, cut through major veins on the underside, and pin flat — plantlets grow from each cut

Division (Tuberous, Rhizomatous)

In spring, divide large tubers or rhizomes with a clean knife, ensuring each piece has at least one growth eye. Let cut surfaces dry for 24 hours before planting.

Common Problems and Solutions

Powdery Mildew

White powdery coating on leaves — the most common begonia disease. Caused by overhead watering and poor air circulation. Water at the base, improve spacing, remove affected leaves. Fungicide if severe.

Stem Rot (Botrytis)

Mushy, collapsing stems with gray fuzzy mold. Usually from overwatering or too-wet conditions. Remove affected stems cleanly. Improve drainage and reduce watering frequency. Ensure good airflow.

Leaf Drop

Sudden leaf drop usually indicates temperature shock (moved from warm to cold or vice versa), severe underwatering, or drafts. Begonias dislike sudden changes — acclimate gradually when moving between indoors and outdoors.

Mealybugs

White cottony clusters in leaf axils and on stems. Common on indoor begonias. Dab with rubbing alcohol on a cotton swab for small infestations. Use insecticidal soap or neem oil for larger problems.

Leggy Growth

Stretched, sparse growth with long bare stems. Caused by insufficient light. Move to a brighter location. Pinch or cut back leggy stems to encourage bushy regrowth. For wax begonias, pinch tips when young to promote branching.

Scorched Leaves

Brown, papery patches on leaves. Caused by direct sun. Move to shadier location immediately. Remove damaged leaves — they will not recover.

Companion Planting

Begonias pair beautifully with other shade-lovers:

• Impatiens — complementary bloom shapes and colors in shade beds
• Ferns — textural contrast, especially with rex begonias
• Coleus — colorful foliage that echoes rex begonia's drama
• Hostas — bold leaf shapes alongside begonia's finer texture
• Caladiums — tropical look with arrow-shaped colorful leaves
• Fuchsia — hanging basket companion with pendulous flowers

Frequently Asked Questions

Do begonias grow in full shade?

Begonias grow well in partial shade (2-4 hours of filtered sun), but most types struggle in full, deep shade with no light at all. The exception is rex begonias, which can thrive in bright indirect light with no direct sun. Wax begonias are the most adaptable — bronze-leaf varieties can actually handle full sun in cooler climates (Zones 3-6), while green-leaf varieties prefer more shade. Tuberous begonias need bright shade but absolutely no direct afternoon sun. The sweet spot for most begonias is morning sun with afternoon shade, or all-day dappled light under a tree canopy.

How do I keep tuberous begonias over winter?

After the first frost kills the foliage, cut stems to 2 inches and dig up the tubers. Let them cure in a warm, dry spot for 1-2 weeks until the remaining stem stub detaches easily. Then store the dry tubers in peat moss or vermiculite at 45-55°F — an unheated basement, garage, or root cellar works well. Check monthly for rot or mold and discard any soft tubers. In late winter (8-10 weeks before your last frost date), bring tubers out and restart them in shallow trays of moist potting mix at 65-70°F. Sprouts appear in 2-4 weeks.

Why are my rex begonia leaves losing their color?

Rex begonia foliage color fades when the plant gets too much or too little light. Too much direct sun bleaches the colors and causes scorching. Too little light makes the leaves revert to mostly green as the plant tries to maximize chlorophyll. The fix is bright, indirect light — an east-facing window is ideal. Also check humidity: low humidity (below 40%) stresses rex begonias and can dull their colors. Use a pebble tray or humidifier to keep humidity around 50-60%.

Can I grow begonias from seed?

Yes, but it requires patience. Begonia seeds are extremely tiny — dust-like, among the smallest of all garden plants. Sow on the surface of moist seed-starting mix (do not cover — they need light to germinate). Cover the tray with a clear dome to maintain humidity. Germination takes 14-21 days at 70-75°F. Seedlings grow very slowly for the first month. Most gardeners prefer buying transplants or propagating from cuttings, which is much faster and easier. If you do grow from seed, start 12-16 weeks before your target planting date.

Are begonias safe for pets?

Begonias are considered mildly toxic to dogs, cats, and horses by the ASPCA. The tubers are the most toxic part, containing soluble calcium oxalates that cause oral irritation, drooling, vomiting, and difficulty swallowing if ingested. The leaves and stems are less concentrated but can still cause mild GI upset. Rex begonias and tuberous begonias tend to be more irritating than wax begonias. Keep begonias out of reach of pets who chew on plants, and store dormant tubers where pets cannot access them.