Begonia (Begonia spp.)

About Begonia

Begonia is a staggeringly diverse genus — with over 2,000 recognized species, it is one of the largest genera of flowering plants on Earth, exceeded in number only by a handful of other mega-genera like Astragalus and Bulbophyllum. This immense diversity means begonias come in forms so varied they can barely be recognized as relatives: from compact, waxy-leaved bedding plants that bloom in full sun, to ethereal rex begonias with leaves that look as though they were painted by an artist with metallic and jewel-toned pigments, to towering cane begonias with bamboo-like stems, polka-dotted foliage, and cascading flower clusters. No single ornamental genus offers such breadth of form, texture, color, and growing habit.

Begonias belong to the family Begoniaceae and are distributed throughout tropical and subtropical regions worldwide, with centers of diversity in Central and South America, Southeast Asia, and central Africa. The genus is divided into several horticultural groups based on root structure and growth habit. Fibrous-rooted begonias (including the ubiquitous wax begonia, B. semperflorens) produce fine, fibrous root systems and are the toughest, most sun-tolerant types. Rhizomatous begonias (including rex begonias, B. rex-cultorum) grow from thick horizontal rhizomes and are prized for their spectacular foliage. Cane-stemmed begonias (including the viral polka dot begonia, B. maculata) produce tall, jointed stems reminiscent of bamboo. Tuberous begonias grow from underground tubers and produce the largest, most rose-like flowers but are poorly suited to Philippine lowland heat.

For Filipino growers, begonias hold special significance because the Philippines is a global center of Begonia biodiversity. With over 250 native species — many found nowhere else on Earth — the Philippine archipelago ranks among the world's richest regions for wild begonia diversity. Filipino botanical expeditions regularly discover and formally describe new Begonia species from remote mountain forests across Luzon, Visayas, and Mindanao. These native Philippine begonias are increasingly prized by international collectors and represent a nationally significant botanical heritage worth both celebrating and conserving.

The most commonly grown begonias in Philippine gardens and homes include wax begonias for sun-exposed beds and borders, rex begonias for indoor collections and terrariums, and cane types like the wildly popular polka dot begonia (B. maculata) that became a social media sensation during the plantita/plantito boom. Prices range from 50 pesos for common wax begonias to 300-800 pesos for popular varieties like B. maculata, and up to 500-5,000 pesos or more for rare native Philippine species that have entered the collector market.

History & Philippine Biodiversity

The genus Begonia was named by Charles Plumier in 1700 in honor of Michel Begon, a French colonial governor and plant enthusiast. European botanical exploration during the 18th and 19th centuries brought hundreds of begonia species from tropical regions into European greenhouses, where hybridization began almost immediately. The Victorian era saw a golden age of begonia cultivation, with rex begonias in particular becoming prized greenhouse specimens admired for their extravagant foliage patterns. The development of wax begonia (semperflorens) hybrids for mass bedding production in the 20th century democratized the genus, making begonias accessible to every gardener rather than just wealthy collectors.

The Philippines occupies a uniquely important position in the global story of Begonia diversity. The archipelago hosts over 250 native Begonia species — an extraordinary number that places the Philippines among the top centers of Begonia biodiversity worldwide. This richness is driven by the Philippines' island geography, tropical mountain forests, high rainfall, and geological complexity. Many Philippine begonias are island endemics — species found on only a single island or even a single mountain, having evolved in isolation over millions of years. Filipino botanists from institutions including the Philippine National Museum, the University of the Philippines, and De La Salle University have collaborated with international researchers from the Royal Botanic Garden Edinburgh and other institutions to document this diversity, with new species being formally described nearly every year.

The cultural significance of Philippine native begonias has grown dramatically in recent years. During the plantita/plantito craze of 2020-2022, Filipino plant collectors discovered that some of the world's most beautiful and rarest begonias grow wild in their own country's forests. Native species like those from Mount Hamiguitan, the Sierra Madre, and the mountains of Palawan became sought-after collector plants. This awareness has contributed to both conservation interest (protecting forest habitats) and ethical collection debates. The Philippine begonia story connects local gardening culture to global botanical science in a uniquely meaningful way — Filipino growers are custodians of one of the planet's richest begonia heritages.

How to Plant Begonias in the Philippines

Begonias are widely available across the Philippines. Wax begonias (50-150 pesos) are found at virtually every garden center and weekend tiangge. Rex begonias (150-500 pesos) are available at plant shops and from online collectors. Cane types including the popular B. maculata (100-800 pesos) are stocked by most plant sellers. Rare native Philippine species (500-5,000+ pesos) circulate through collector groups and specialty sellers. Facebook plant groups are the primary marketplace for rare and collector begonias.

Planting Steps

1. Select a begonia type suited to your conditions: Outdoor beds with some sun: wax begonia (semperflorens) — the toughest type. Indoor bright indirect light: cane/angel wing types (including B. maculata). Humid indoor spots, terrariums, or collections: rex begonias — the most spectacular foliage but the most demanding care. For beginners, start with wax or cane types before progressing to finicky rex varieties.
2. Pot in a light, airy growing mix: Combine coco peat, perlite, and chopped orchid bark (2:1:1) for a light, fast-draining mix. Begonia roots are fine and need excellent aeration — heavy, compacted soil causes root rot rapidly. For rex begonias, add chopped sphagnum moss for extra moisture retention without compaction. Use pots with drainage holes, slightly snug (2-3 cm wider than the root ball). Terracotta pots provide beneficial aeration for begonia roots.
3. Position in bright indirect light to partial shade: Most begonias need bright but indirect light — the gentle illumination near (but not in) a window, under shade cloth, or in dappled tree shade. Rex begonias need the most shade and burn easily in direct sun. Wax begonias tolerate 2-4 hours of gentle morning sun. Cane types prefer bright filtered light. East-facing positions in Filipino homes work well for most types.
4. Water at the base — never on the foliage: Allow the top 2-3 cm of soil to dry slightly between waterings, then water thoroughly at the base. NEVER water from overhead or allow water to sit on begonia leaves — wet foliage causes spotting, powdery mildew, and botrytis rot. This is the single most important care rule for begonias in the humid Philippines where fungal disease spreads rapidly on wet leaf surfaces.
5. Provide humidity without wetting leaves: Rex and cane begonias thrive in humidity of 60-80% — naturally provided by Philippine ambient conditions. In air-conditioned rooms (which dry the air to 30-40%), raise humidity with pebble trays (shallow tray of pebbles and water beneath the pot), grouping plants together, or growing in terrariums. Do NOT mist rex begonia leaves — water on their textured surfaces causes rot spots rather than benefiting the plant.

Propagation

Rex begonias: leaf propagation — cut a leaf into wedge sections containing major veins, lay on moist perlite/sphagnum, plantlets emerge from vein cuts in 4-8 weeks. Whole-leaf method: make cuts across leaf veins, pin flat on moist medium, plantlets form at each cut. Cane/angel wing types: stem cuttings 10-15 cm with 2+ nodes, root in water or moist perlite in 2-4 weeks. Wax begonias: stem cuttings root easily in water or moist mix in 2-3 weeks. Rhizomatous types: divide rhizomes when repotting. All begonia types propagate readily — the leaf propagation of rex begonias is one of the most rewarding propagation experiences in horticulture.

Care Guide

Sunlight

Bright indirect to partial shade — the specific requirement varies by type. Rex begonias need the most shade: bright ambient light without any direct sun (which burns their delicate, textured leaves). Wax begonias are the most sun-tolerant: they handle 2-4 hours of gentle morning sun and even tolerate some afternoon sun in cool highland areas. Cane types (angel wing, polka dot) prefer bright filtered light — the dappled illumination under shade cloth or near bright windows. In Philippine conditions, east-facing positions provide ideal morning light for most types. Avoid west-facing exposures where harsh afternoon sun scorches foliage.

Water

Moderate — let the top 2-3 cm of soil dry slightly between waterings, then water thoroughly. Begonias occupy a middle ground: they need regular moisture but rot quickly in waterlogged soil. The critical rule: ALWAYS water at the base, never from overhead. Wet foliage in Philippine humidity leads rapidly to powdery mildew, botrytis, and bacterial leaf spot. In well-draining mix, water every 4-7 days indoors. Reduce frequency in air-conditioned rooms where evaporation is slower. Rex begonias in terrariums need watering only every 2-4 weeks due to the enclosed humidity.

Soil

Light, well-draining, slightly acidic. pH 5.5-6.5. Begonia roots are fine and fibrous, demanding excellent aeration — they suffocate and rot in dense, heavy soil. The ideal mix: coco peat + perlite + orchid bark (2:1:1). For rex types, add chopped sphagnum moss. Avoid standard garden soil (too heavy and compacting). The mix should feel light and fluffy, draining within seconds when watered. Repot every 1-2 years in fresh mix, or when roots become crowded. Avoid overpotting — excess soil around small root systems stays wet and promotes rot.

Humidity & Temperature

Begonias thrive in humidity of 50-80% — and Philippine ambient humidity (65-85%) naturally provides this, giving Filipino growers a significant advantage over temperate growers who struggle to maintain adequate humidity. The challenge in Philippine homes is air conditioning, which drops humidity to 30-40% — below the comfort level for rex begonias especially. Solutions: pebble trays, grouping plants, terrariums for rex types, or positioning begonias in non-air-conditioned areas (bathrooms, kitchens, covered patios). Temperature: 18-30 degrees Celsius. Begonias are sensitive to cold below 13 degrees Celsius and heat above 35 degrees Celsius. Philippine lowland temperatures are generally fine, though highland areas (Baguio, Tagaytay) offer the most ideal conditions.

Fertilizer

Moderate feeder. Apply balanced liquid fertilizer (10-10-10 or 14-14-14) at half strength every 2-3 weeks during active growth. For flowering types (wax and cane begonias), a bloom-boosting formula (higher phosphorus) enhances flower production. For rex begonias grown primarily for foliage, balanced nutrition supports leaf size and coloration. Avoid over-fertilizing — excess salts burn the delicate root system and cause leaf edge browning. Organic fish emulsion (diluted) and worm casting tea are gentle, effective organic options. Reduce feeding during cooler months when growth slows.

Pruning

Type-dependent. Wax begonias: pinch growing tips to encourage bushier growth and remove spent flower clusters. Cane/angel wing types: prune tall canes back by one-third to promote branching — unpruned cane begonias become top-heavy and leggy. Cut just above a node; new shoots emerge below the cut. Rex begonias: remove old or damaged leaves at the base — minimal pruning needed as growth is naturally compact. For all types: remove any leaves showing disease spots (powdery mildew, rot) immediately to prevent spread. Sterilize cutting tools between plants to avoid transmitting disease.

Growing Medium Options

Ornamental Uses

Begonias serve an extraordinarily wide range of ornamental roles — from mass bedding displays to collector terrariums to architectural indoor statements. Few other genera can fill so many different design niches, and the diversity of form, color, and texture within the genus means there is a begonia for virtually every ornamental application in shade or partial shade conditions.

Indoor & Collection Displays

• Rex begonia terrarium collection: Rex begonias displayed in glass terrariums create living art installations — the metallic, jewel-toned leaves are showcased beautifully through glass while the enclosed environment provides the humidity these foliage specialists demand. Multiple terrariums create a stunning indoor collection
• Polka dot begonia statement plant: A mature B. maculata in a decorative pot makes a dramatic interior focal point — the silver-spotted leaves with red undersides are among the most photogenic of all houseplants. Position on plant stands, shelving, or tabletops in bright indirect light
• Angel wing begonia floor specimen: Tall cane begonias reaching 100-150 cm become impressive structural plants for bright indoor corners, flanking furniture, or filling vertical space in room designs. The hanging flower clusters add seasonal color to the architectural form
• Mixed begonia shelf display: Collections of different begonia types on open shelving create a living gallery of foliage textures and patterns — rex varieties provide color and pattern, cane types add height and structure, and wax types contribute flowers

Outdoor & Landscape Uses

• Wax begonia bedding and borders: Mass plantings of wax begonias in shaded to partially sunny beds create uniform, continuously blooming ground-level displays. Available in coordinated colors (red, pink, white) for formal designs. The toughest begonia for Philippine outdoor conditions
• Shade garden accent: Begonias planted among ferns, aglaonema, and calathea add diversity of form to shade garden compositions. Rex types contribute foliage drama while wax types add flower color in positions too shaded for most other blooming plants
• Container gardens on shaded patios: Mixed begonia containers on covered terraces and shaded balconies create lush, tropical-feeling displays with minimal sun requirements — perfect for the shaded outdoor living spaces common in Filipino homes

Air Quality & Oxygen

Begonias contribute to indoor air quality through photosynthesis — absorbing carbon dioxide and producing oxygen during daylight hours. While begonias were not specifically included in the NASA Clean Air Study, research from Kamal Meattle and the Central Pollution Control Board (India) has referenced begonias among tropical plants that contribute to indoor air quality improvement when grown in sufficient numbers. The broad foliage of rex and cane begonias provides meaningful leaf surface area for gas exchange relative to their pot size.

For Filipino indoor environments, begonias in collections and terrariums contribute to micro-environment quality through transpiration (adding moisture to dry air-conditioned rooms) and oxygen production. The humidity released through transpiration is particularly beneficial in air-conditioned spaces where dry air causes discomfort. Beyond measurable air quality contributions, the psychological impact of surrounding indoor spaces with the spectacular foliage of rex begonias and the sculptural forms of cane types is significant — natural beauty, varied textures, and living color in indoor environments are consistently associated with reduced stress, improved mood, and greater satisfaction with living spaces.

Toxicity & Safety

Humans: Begonias contain calcium oxalate crystals, concentrated most heavily in the underground parts (tubers, rhizomes, and roots). Chewing or ingesting these parts causes oral irritation, burning sensation, and swelling. The leaves and stems contain lower concentrations and are less likely to cause significant reaction. Despite the calcium oxalate content, begonia toxicity to humans is classified as mild — accidental ingestion of a small amount of leaf material typically causes only minor oral discomfort. Handle rhizomes and tubers with care during repotting and propagation — wash hands after contact. Keep away from small children who might mouth plant parts, though the risk of serious harm is low.

Pets: The ASPCA lists begonias as toxic to dogs and cats. Calcium oxalate crystals — most concentrated in the roots and tubers — cause oral irritation, drooling, vomiting, and difficulty swallowing when chewed. The toxicity is classified as MILD: while unpleasant, serious or life-threatening reactions are rare. The immediate pain from calcium oxalate crystals typically causes the animal to stop chewing before ingesting a significant amount. For pet-owning households: place begonias on elevated surfaces, use hanging planters, grow rex types in enclosed terrariums (naturally pet-proof), or choose pet-free rooms. If a pet chews begonia: rinse mouth with water, offer milk to soothe tissues, and monitor. Consult a veterinarian if symptoms are severe or persistent.

Common Pests & Diseases in the Philippines

• Powdery mildew: White, powdery fungal coating on leaf surfaces — the most common begonia disease in the Philippines. Thrives in warm, humid conditions with poor air circulation — exactly the conditions that characterize many Filipino indoor growing environments. Prevention: ensure good air circulation around plants, avoid wetting foliage, space plants adequately. Treatment: remove affected leaves, improve ventilation, apply sulfur-based or potassium bicarbonate fungicide spray.
• Botrytis (gray mold): Fuzzy gray mold on flowers, stems, and leaves — develops rapidly on wet plant tissue in humid, stagnant air. Particularly destructive on rex begonia leaves where water sits in the textured surface. Prevention: water at the base only, ensure air movement, remove spent flowers and dead leaves promptly. Treatment: remove all affected tissue, improve air circulation, fungicide spray for persistent problems.
• Stem rot (Pythium, Rhizoctonia): Stems turn soft, brown, and mushy at the soil line — caused by waterlogged growing medium with poor drainage. The #1 cause of begonia death. Prevention: use light, fast-draining potting mix, pots with drainage holes, allow top soil to dry slightly between waterings. Treatment: cut away rotted stem above the infected area, re-root the healthy top section as a cutting, and discard the rotted base and contaminated soil.
• Mealybugs: White, cottony clusters at leaf axils, on stems, and on leaf undersides. Suck sap and excrete sticky honeydew. Inspect regularly — mealybugs hide in the crevices of begonia stems and leaf bases where they are easily overlooked. Remove with alcohol-dipped cotton swabs or spray with neem oil. Persistent infestations require systemic insecticide.
• Snails and slugs: Common in the moist, shaded conditions begonias prefer (especially outdoor plantings). Chew irregular holes in leaves and can devastate young plants overnight. Handpick at night, use beer traps, apply iron phosphate bait, or surround pots with crushed eggshell barriers. Particularly problematic during the Philippine wet season when populations boom.

Frequently Asked Questions

Sources

• Plants of the World Online — Begonia. Royal Botanic Gardens, Kew.
• ASPCA — Animal Poison Control Center: Toxic and Non-Toxic Plant Lists — Begonia.
• Hughes, M. et al. (2015). Begonia sect. Baryandra: Philippine Endemic Begonias. Edinburgh Journal of Botany.
• American Begonia Society — Cultural Information and Classification of Begonia.
• Peng, C.I. et al. (2015). New Species of Begonia from the Philippines. Botanical Studies, 56:30.

This guide is for informational purposes. Begonias are mildly toxic — keep away from pets and small children.