Saribus merrillii: A comprehensive Growing Guide for Enthusiasts & Collectors.
Saribus merrillii
1. Introduction
Habitat and Distribution
Saribus merrillii is endemic to the Philippines, specifically found in Palawan and nearby smaller islands including the Calamian Group. This palm inhabits coastal and lowland forests, often growing on limestone karst formations and coral-derived soils from sea level to 500 meters elevation. It thrives in areas with high rainfall and is frequently found along seasonal streams, forest edges, and in secondary growth forests where it benefits from increased light availability.
Native Continent
Scientific Classification
Synonyms
- Livistona merrillii Becc. (basionym)
- Livistona chinensis var. merrillii (Becc.) Becc.
- Pritchardiopsis merrillii (Becc.) Becc.
- Livistona philippinensis Becc. (misapplied)
Common Names
- English: Merrill's fan palm, Philippine fan palm, Palawan fan palm
- Filipino/Tagalog: Anahaw (though this name is more commonly used for other species)
- Palawan local names: Bayas, Silag
- Trade name: Christmas palm (confused with Veitchia merrillii)
Global Expansion
Saribus merrillii has achieved moderate distribution in cultivation:
Every cultivated specimen of Saribus merrillii contributes to the preservation of Philippine biodiversity. As habitat loss continues in Palawan, ex-situ cultivation becomes increasingly important for species survival. The palm's hermaphroditic nature ensures that even single specimens can produce viable seeds for conservation efforts.
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- Southeast Asia: Widely cultivated in Thailand, Malaysia, Indonesia
- China: Southern provinces, particularly Guangdong and Hainan
- United States: Florida, Hawaii, Southern California collections
- Australia: Queensland tropical gardens
- Caribbean: Limited cultivation in Puerto Rico and Trinidad
- Middle East: UAE and Saudi Arabia in irrigated landscapes
The species has gained popularity due to its compact size and attractive appearance, though it is sometimes confused with the more common Livistona chinensis in the trade. Its expansion has been facilitated by increased interest in Philippine endemic palms and conservation-through-cultivation initiatives.
2. Biology and Physiology
Morphology
Trunk/Stem
Saribus merrillii develops a solitary, slender to moderately robust trunk reaching 10-20 meters in height with a diameter of 15-25 cm. The trunk is gray-brown, marked with prominent, closely spaced leaf scars forming distinctive rings. Young palms retain leaf bases for several years, creating a rough texture, while mature specimens display a smoother trunk. The trunk base may be slightly swollen, particularly in limestone habitats.
Leaves
The crown consists of 25-35 costapalmate leaves forming a dense, spherical to slightly spreading canopy. Individual leaf blades measure 1.2-1.8 meters across, divided to about one-third to half their length into 50-70 segments. Leaves are bright green to deep green above with a slightly paler underside. The petiole extends 1-1.5 meters, armed with sharp, curved teeth along the margins, particularly pronounced in juvenile plants. The hastula is prominent, asymmetric, and pointed.
Flower Systems
Saribus merrillii is hermaphroditic, producing cream to yellowish flowers in branched inflorescences. The inflorescence emerges from among the lower leaves, extending 0.8-1.2 meters with 2-3 orders of branching. Individual flowers measure 4-5 mm across, with 3 sepals, 3 petals fused at the base, 6 stamens with filaments united basally, and a single pistil. Flowering occurs primarily during the dry season (December to May in native habitat) with fruits maturing in 4-6 months.
Life Cycle
- Germination phase: 1-3 months
- Seedling establishment: 1-2 years
- Juvenile phase: 3-5 years
- Sub-adult phase: 5-10 years
- Reproductive maturity: 8-12 years
- Peak productivity: 15-40 years
- Senescence: After 60-80 years
- Maximum lifespan: Estimated 100-150 years
Climate Adaptations
- Monsoon adaptation: Tolerates seasonal drought and flooding
- Limestone adaptation: Efficient calcium metabolism
- Salt tolerance: Moderate coastal salt spray resistance
- Typhoon resistance: Flexible leaves and strong trunk
- Light plasticity: Shade tolerant when young, sun-demanding at maturity
3. Reproduction and Propagation
Seed Reproduction
Seed Morphology and Diversity
Seeds are globose to slightly ellipsoid, measuring 10-14 mm in diameter. The seed coat is thin, brown to black when fully mature, with a smooth to slightly roughened texture. The endosperm is white, homogeneous, and hard. The embryo is lateral, positioned near the base. Seed weight ranges from 0.6-1.0 grams. Intraspecific variation exists between island populations, with Palawan populations showing larger seeds than Calamian populations.
Seed Collection and Viability Testing
Ripeness indicators: Fruits easily detach, soft pericarp
Processing: Remove pericarp within 24 hours
Cleaning: Thorough washing to prevent fungal growth
Viability window: Best within 2 months, maximum 4 months
Testing methods:
- Float test (viable seeds sink)
- Tetrazolium test for accurate viability
- Cut test showing firm white endosperm
Pre-germination Treatments
- File opposite the embryo gently
- Soak in hot water (60°C) for 5 minutes
- Acid scarification not recommended
- Room temperature water for 72 hours
- Change water daily to prevent fermentation
- Add fungicide to soaking water if available
Step-by-step Germination Techniques
- Seed selection: Choose plump, heavy seeds
- Treatment: File and soak as described
- Medium preparation: Mix 40% coconut coir, 40% perlite, 20% vermiculite
- Container: Use deep containers for taproot development
- Sowing: Plant horizontally at seed diameter depth
- Temperature: Maintain 28-32°C for optimal results
- Humidity: Cover with plastic, maintain 75-85%
- Light: Bright shade or 50% shade cloth
- Moisture: Keep evenly moist, never waterlogged
- Monitoring: Check daily, remove any moldy seeds
Germination Difficulty: Easy to Moderate
- Success rate with fresh seeds: 70-85%
- Main challenges: Seed freshness and temperature consistency
Germination Time
- Initial root emergence: 3-5 weeks
- Shoot emergence: 5-8 weeks
- First leaf expansion: 10-12 weeks
- Variation depends on: Temperature and seed freshness
Seedling Care and Early Development
- Weeks 1-4: Maintain high humidity under cover
- Months 2-3: Gradually reduce humidity
- Months 3-6: Begin monthly weak fertilization
- Months 6-12: Increase light gradually to 70%
- Year 1-2: Transplant when 4-5 leaves present
Advanced Germination Techniques
Hormonal Treatments
- GA3: 300-500 ppm for 24 hours
- IBA: 100 ppm for root enhancement
- Cytokinin: 50 ppm combined with GA3
- Seaweed extract: Natural hormone source, weekly application
Environmental Optimization
- Bottom heat at 30°C constant
- Diurnal temperature fluctuation (25°C night, 32°C day)
- Controlled humidity chambers
- Sterile technique for high-value seeds
4. Cultivation Requirements
Light Requirements
Species-specific Light Tolerance
- Germination: Deep shade (20-30% full sun)
- Seedlings (0-1 year): 40-50% shade
- Juveniles (1-5 years): 50-70% full sun
- Sub-adults (5-10 years): 70-100% full sun
- Adults: Full sun preferred, tolerates light shade
Seasonal Light Management
- Wet season: Can tolerate lower light
- Dry season: Requires maximum light
- Transition periods: Gradual adjustment over 3-4 weeks
Artificial Lighting for Indoor Cultivation
- Type: LED grow lights, full spectrum
- Intensity: 200-400 μmol/m²/s for adults
- Photoperiod: 12-14 hours
- Distance: 60-90 cm from crown
- Supplementation: UV-A beneficial for compact growth
Temperature and Humidity Management
Optimal Temperature Ranges
- Ideal day temperature: 25-33°C (77-91°F)
- Night temperature: 20-25°C (68-77°F)
- Absolute maximum: 42°C (108°F) with adequate water
- Minimum tolerance: 2°C (36°F) for brief periods
Cold Tolerance and Hardiness
- Hardiness Zone: USDA 10a-12
- Frost damage: Occurs below 0°C
- Lethal temperature: -3°C sustained
- Recovery ability: Good from minor cold damage
Humidity Requirements
- Optimal range: 65-80%
- Minimum tolerance: 45% with increased watering
- Maximum tolerance: 90% with air movement
Soil and Nutrition
Ideal Soil Composition
- pH preference: 6.5-8.0 (limestone tolerant)
- Texture: Sandy loam to clay loam
- Organic content: 4-8%
- Special adaptation: Thrives in calcareous soils
- Recommended mix: 35% loam, 25% compost, 20% perlite, 20% limestone chips
Nutrient Requirements
- Vegetative growth: 10-5-10 NPK ratio
- Mature plants: 8-4-12 NPK with micronutrients
- Application rate: 100-150g per plant monthly
- Slow-release: 6-month formulation preferred
Micronutrient Management
- Calcium: Often adequate in limestone soils
- Magnesium: Regular Epsom salt applications
- Iron: Chelated iron for chlorosis
- Boron: Important for fruit set
- Zinc: Foliar application beneficial
Water Management
Irrigation Requirements
- Growing season: Deep watering 2-3 times weekly
- Dry season: Daily watering may be needed
- Cool season: Once weekly sufficient
- Volume: 15-30 liters per mature plant
Drought Tolerance
- Rating: Moderate when established
- Survival period: 2-4 weeks without irrigation
- Stress signs: Leaf tip browning, reduced growth
- Recovery: Rapid with resumed watering
Water Quality
- pH tolerance: 6.0-8.5
- Salinity: Moderate tolerance (up to 1,500 ppm TDS)
- Calcium: Beneficial in water
- Chlorine: Sensitive, dechlorinate if possible
Drainage Requirements
- Critical factor: Must have good drainage
- Percolation rate: Minimum 2.5 cm/hour
- Amendments: Add perlite or sand if needed
- Raised beds: Beneficial in heavy soils
5. Diseases and Pests
Common Problems
- Yellowing leaves: Usually nitrogen or magnesium deficiency
- Tip burn: Low humidity or fluoride toxicity
- Stunted growth: Inadequate light or root-bound
- Leaf spots: Various fungal pathogens
Disease Identification
Fungal Diseases
- Leaf spot (Pestalotiopsis): Brown spots with yellow halos
- Anthracnose: Dark, sunken lesions on leaves
- Ganoderma butt rot: Fatal trunk rot, no cure
- Graphiola leaf spot: Small black pustules on leaves
- Treatment: Copper fungicides, improve air circulation
Bacterial Diseases
- Bacterial bud rot: Foul-smelling crown rot
- Leaf blight: Water-soaked lesions
- Treatment: Remove affected parts, copper bactericides
Pest Identification
- Rhinoceros beetle: Bore into crown, use pheromone traps
- Red palm weevil: Trunk damage, systemic insecticides
- Scale insects: Sucking pests, horticultural oil
- Mealybugs: White cottony masses, insecticidal soap
- Leaf miners: Serpentine trails, systemic insecticides
Protection Methods
Environmental
- Adequate spacing (4-5 meters)
- Avoid overhead irrigation
- Remove dead fronds promptly
- Mulch to prevent splash
- Quarantine new plants
Chemical
- Monthly preventive sprays in wet season
- Rotate fungicide classes
- Systemic insecticides for borers
- Always follow label directions
6. Indoor Palm Growing
Specific Indoor Care
Container Selection
- Size: Minimum 50cm diameter for adults
- Depth: At least 60cm for taproot
- Material: Heavy ceramic or fiberglass
- Drainage: Multiple large holes essential
Environmental Requirements
- Light: Brightest available location
- Temperature: 18-28°C year-round
- Humidity: Increase to 60% minimum
- Air circulation: Fan for air movement
Special Considerations
- Rotate quarterly for even growth
- Clean leaves monthly
- Watch for spider mites in dry air
- May need supplemental lighting
Replanting Procedures
- Timing: Spring optimal
- Preparation: Water well 2 days prior
- Pot selection: 25% larger diameter
- Root inspection: Trim only damaged roots
- Positioning: Same planting depth
- Backfilling: Firm gently as you go
- Watering: Thoroughly until drainage
- Recovery: Shade and high humidity for 2 weeks
Wintering Indoor Palms
- Temperature: Minimum 15°C
- Watering: Reduce frequency 50%
- Fertilization: Suspend November-February
- Humidity: Critical to increase
- Pests: Monitor for scale and mites
- Light: Supplement if needed
7. Landscape and Outdoor Cultivation
Design Applications
- Avenue planting: Excellent for formal drives
- Specimen: Strong architectural element
- Group planting: Stunning grove effect
- Poolside: Tropical atmosphere
- Coastal gardens: Good salt tolerance
- Urban landscapes: Pollution tolerant
- Conservation gardens: Important for species preservation
Site Selection
- Consider 4-meter crown spread
- Allow for 20-meter eventual height
- Well-draining location essential
- Protection from strong winds when young
- Avoid frost pockets
- Consider overhead clearance
8. Cold Climate Cultivation Strategies
Cold Hardiness Assessment
- Optimal growth: 25-33°C
- Growth cessation: Below 15°C
- Chilling damage: Below 5°C
- Frost damage: At 0°C
- Death: Below -3°C
Winter Protection Systems
Preventive Measures
- Site selection near thermal mass
- Mulch heavily before cold
- Anti-desiccant sprays
- Temporary windbreaks
Active Protection
- Wrap trunk with insulation
- Cover crown with frost cloth
- String Christmas lights for heat
- Build temporary greenhouse
Hardiness Zone Specifications
- Zone 12: No protection needed
- Zone 11: Rare cold protection
- Zone 10b: Occasional protection
- Zone 10a: Regular monitoring and protection
- Zone 9b: Container culture recommended
Winter Protection Materials
- Frost blankets (multiple layers)
- Pipe insulation for trunk
- Heat cables for extreme events
- Bubble wrap for additional insulation
- Pine straw or hay bales
Establishment and Maintenance in Landscapes
Planting Techniques for Success
- Site analysis: Drainage test mandatory
- Soil improvement: Add organic matter
- Hole preparation: 3x root ball width
- Base preparation: Add gravel for drainage
- Mycorrhizal inoculant: Beneficial addition
- Remove container carefully
- Inspect and loosen roots
- Position at correct height
- Backfill in layers
- Water each layer
- Create water basin
- Apply thick mulch
- Stake if necessary
- Provide shade initially
Long-term Maintenance Schedules
- Deep watering check
- Fertilization (growing season)
- Pest inspection
- Dead frond removal
- Nutritional assessment
- Growth measurement
- Mulch renewal
- Micronutrient application
- Comprehensive health check
- Soil testing
- Major pruning
- Support system check
- Photograph for records
- Consider relocation if needed
- Major crown cleaning
- Root barrier assessment
- Complete soil renovation
Final Summary
Saribus merrillii stands as one of the Philippines' most attractive endemic fan palms, combining moderate size with exceptional ornamental qualities. This species offers gardeners and landscapers a manageable fan palm that reaches 10-20 meters in height, making it suitable for a wider range of landscape applications than larger species. Its bright green, nearly circular leaves and slender trunk create an elegant tropical appearance that has made it increasingly popular in cultivation worldwide.
The palm's natural adaptation to limestone soils provides unusual versatility in cultivation, thriving in both acidic and alkaline conditions (pH 6.5-8.0). This characteristic, combined with its moderate drought tolerance once established, makes it particularly valuable for challenging soil conditions where other palms might struggle. Its origin in the Philippine archipelago has endowed it with good tolerance to humid conditions and moderate resistance to wind, though not to the extreme level of true coastal palms.
Successful cultivation centers on providing excellent drainage (absolutely critical), consistent moisture during establishment, and gradual acclimatization from shade to sun as the palm matures. The species shows good vigor with fresh seeds germinating readily (70-85% success rate), though seed viability declines rapidly after 2-4 months. Its relatively fast growth rate compared to other fan palms means landscape specimens can be established within 5-8 years from seed.
Temperature tolerance limits outdoor cultivation to USDA zones 10a-12, with brief tolerance to near-freezing temperatures but no true frost hardiness. This makes it ideal for tropical and subtropical regions but requires protection or container culture in marginal zones. Indoor cultivation is possible but challenging due to high light requirements and the palm's eventual size.
From a conservation perspective, Saribus merrillii faces habitat pressure from deforestation in its native range, particularly in Palawan. Cultivation serves dual purposes of ornamental horticulture and ex-situ conservation, with each garden specimen contributing to the species' preservation. The palm's moderate size, attractive appearance, and relative ease of cultivation make it an excellent choice for botanical gardens, palm collectors, and tropical landscapes.
The species rewards proper cultivation with steady growth, reaching reproductive maturity in 8-12 years and potentially living for over a century. Its hermaphroditic flowers ensure fruit production even from single specimens, providing seeds for propagation and contributing to conservation efforts. For those seeking a manageable, attractive fan palm with interesting provenance and good landscape qualities, Saribus merrillii offers an excellent choice that combines beauty with botanical significance.