1. Introduction

Habitat and Distribution, Native Continent

Pritchardia beccariana is endemic to the windward coastal regions and low elevations of East Maui, Hawaiian Islands, with historical populations on the Kona (leeward) coast of Hawaii Island that are now believed extinct. On Maui, the remaining populations are found in scattered locations along the Hāna coast from sea level to 300 meters elevation, primarily on steep coastal cliffs, rocky outcrops, and in wind-swept coastal shrublands. The habitat is characterized by salt spray exposure, constant trade winds, annual rainfall of 1,500-3,000mm, and volcanic or limestone-derived soils. This species has adapted to one of Hawaii's most challenging environments where few other palms can survive.

Taxonomic Classification and Scientific Classification

Synonyms

• Washingtonia beccariana (Rock) Kuntze (invalid combination)
• Pritchardia eriocarpa sensu Becc., non Becc. (misapplied)
• Sometimes confused with P. arecina in literature

Common Names

• Beccari's pritchardia (English)
• Coastal pritchardia (English)
• Loulu (Hawaiian - general term)
• Loulu kai (Hawaiian - "sea loulu")
• Hāna coast palm (Local usage)
• 贝卡里蒲葵 (Chinese)

Expansion in the World

P. beccariana has limited but growing presence in cultivation:

• National Tropical Botanical Garden, Hawaii (multiple sites)
• Ho'omaluhia Botanical Garden, Oahu
• Private collections in Hawaii (increasing)
• Some California coastal collections
• Rare in Florida collections
• Seeds occasionally available from specialists
• IUCN Red List status: Endangered

Better representation in cultivation than many Hawaiian endemics due to coastal habitat accessibility and relatively higher seed production.

2. Biology and Physiology

Morphology

Trunk

P. beccariana develops a solitary, relatively short and stout trunk reaching 5-10 meters in height with a diameter of 20-30cm. The trunk is gray to brown, prominently marked with persistent leaf base scars that create a cross-hatched pattern. Wind exposure often results in curved or leaning trunks. The base frequently shows buttressing, unusual in Pritchardia, likely an adaptation to cliff habitats. Salt spray exposure gives the trunk a weathered, roughened texture.

Leaves

The crown is compact and wind-adapted, consisting of 15-25 costapalmate leaves. Leaf blades are notably thick and leathery, 70-100cm wide, divided one-third to halfway into 35-50 segments. The key adaptation is the extremely rigid, wind-resistant leaves with a distinctive blue-green to gray-green color and waxy coating. Petioles are relatively short (60-100cm) and very stout. Young leaves have sparse woolly tomentum that quickly weathers away. The hastula is small and often asymmetric.

Flower Systems

P. beccariana is hermaphroditic with compact infrafoliar inflorescences adapted to wind exposure. The panicle is relatively short (40-80cm), stout, and held close to the trunk. Flowers are small (3-4mm), cream to pale yellow, densely clustered on short, thick rachillae. The entire inflorescence structure shows adaptations to prevent wind damage. Flowering occurs primarily in summer months (June-September), possibly triggered by day length and temperature.

Life Cycle

P. beccariana has a moderate lifespan of 60-100 years:

• Germination to Seedling (0-4 years): Slow establishment
• Juvenile Phase (4-15 years): Extended juvenile period
• Sub-adult Phase (15-25 years): Trunk development
• Adult Phase (25-70 years): Regular reproduction
• Senescent Phase (70-100 years): Wind damage accumulation

First flowering occurs at 20-30 years, relatively early for Hawaiian Pritchardia.

Specific Adaptations to Climate Conditions

• Salt Tolerance: Waxy cuticle protects from spray
• Wind Resistance: Short stout trunk, rigid leaves
• Drought Adaptation: Survives dry periods
• Cliff Anchoring: Extensive root system
• Blue-green Coloration: Reflects intense coastal sun
• Compact Growth: Reduces wind resistance

3. Reproduction and Propagation

Seed Reproduction

Seed Morphology and Diversity

P. beccariana produces medium-sized globose to slightly ovoid fruits, 2-3cm diameter. Immature fruits are green with a waxy bloom, ripening to brown or purplish-brown. The fruit surface is smooth with a distinctive glossy appearance when fresh. The pericarp is moderately thick and corky, adapted for ocean dispersal; mesocarp is minimal; endocarp is thin but tough. Seeds are globose, 1.5-2cm diameter, with homogeneous endosperm. Fresh seed weight is 2-5 grams. Moderate genetic diversity exists between populations.

Detailed Seed Collection and Viability Testing

Pre-germination Treatments

Step-by-step Germination Techniques

1. Medium: 40% coarse sand, 30% coconut coir, 20% perlite, 10% crushed coral
2. Container: Deep pots with excellent drainage
3. Sowing: Plant 2-3cm deep
4. Temperature: 24-30°C (75-86°F)
5. Humidity: 65-75% (lower than rainforest species)
6. Light: Bright filtered light from start
7. Special: Slight salinity tolerance in irrigation

Germination Difficulty

Moderate. Key factors:

• Temperature consistency important
• Good drainage essential
• Lower humidity tolerated
• Faster than highland species

Germination Time

• First emergence: 60-120 days
• Peak germination: 120-180 days
• Complete process: 240 days
• Success rate: 60-80%

Seedling Care and Early Development

Advanced Germination Techniques

Hormonal Treatments for Germination Enhancement

4. Cultivation Requirements

Light Requirements

Species-specific Light Tolerance Ranges

• Seedlings (0-2 years): 500-1000 μmol/m²/s (60-70% shade)
• Juveniles (2-5 years): 1000-1800 μmol/m²/s (30-50% shade)
• Sub-adults (5-10 years): 1800-2200 μmol/m²/s (full morning sun)
• Adults: Full sun preferred (2200+ μmol/m²/s)

High light tolerance once established.

Seasonal Light Variations and Management

• Adapts to seasonal changes well
• Young plants need some protection
• Adults thrive in full exposure
• Coastal sun intensity tolerated

Artificial Lighting for Indoor Cultivation

• High light needs challenging
• Metal halide or LED required
• 14-16 hours photoperiod
• 400+ foot-candles minimum

Temperature and Humidity Management

Optimal Temperature Ranges

• Ideal: 22-30°C (72-86°F)
• Acceptable: 15-35°C (59-95°F)
• Minimum survival: 8°C (46°F)
• Maximum tolerance: 40°C (104°F)
• Wide temperature tolerance

Cold Tolerance Thresholds

• Light damage: 10°C (50°F)
• Severe damage: 5°C (41°F)
• Death likely: 2°C (36°F)
• Brief cold snaps tolerated

Hardiness Zone Maps

• USDA Zones: 10a-11
• Zone 9b possible in coastal areas
• Sunset Zones: 22-24
• Salt spray adds cold protection

Humidity Requirements and Modification

• Optimal: 50-70%
• Minimum tolerable: 35%
• Adapts to dry conditions
• Salt spray substitutes for humidity

Soil and Nutrition

Ideal Soil Composition and pH

Nutrient Requirements Through Growth Stages

Organic vs. Synthetic Fertilization

Micronutrient Deficiencies and Corrections

• Iron: Occasional in alkaline soils
• Magnesium: Epsom salts helpful
• Manganese: Rare deficiency
• Boron: Coastal soils often sufficient

Water Management

Irrigation Frequency and Methodology

• Moderate water needs
• Drought-tolerant once established
• Deep, infrequent watering
• Tolerates brief dry periods

Drought Tolerance Assessment

• Good drought tolerance for Pritchardia
• Survives several weeks without water
• Leaves fold but recover
• Deep roots access moisture

Water Quality Considerations

• Tolerates saline water
• Brackish water acceptable short-term
• pH 6.5-8.5 tolerated
• High mineral content okay

Drainage Requirements

• Excellent drainage mandatory
• No waterlogging tolerance
• Raised beds in heavy soil
• Gravel mulch beneficial

5. Diseases and Pests

Common Problems in Growing

• Root rot: Only in poor drainage
• Scale insects: Occasional
• Rat damage: To fruits
• Wind damage: Physical injury

Identification of Diseases and Pests

Disease Issues:

• Minimal disease problems
• Phytophthora only if overwatered
• Leaf spots rare
• Very disease resistant

Pests:

• Coconut scale: On leaves
• Mealybugs: Minor issue
• Palm weevil: Rare
• Generally pest-free

Environmental and Chemical Protection Methods

Cultural Prevention:

• Proper drainage prevents issues
• Good air circulation
• Remove damaged fronds
• Natural resistance high

If Treatment Needed:

• Neem oil for scales
• Rarely needs intervention
• Focus on cultural practices

6. Indoor Palm Growing

Specific Care in Housing Conditions

Indoor Challenges:

• High light requirements
• Low humidity tolerance helps
• Moderate size manageable
• Air circulation important

Success Factors:

• Maximum light essential
• Well-draining mix
• Moderate temperatures fine
• Less demanding than forest species

Replanting and Wintering

Replanting Schedule:

• Every 2-3 years adequate
• Spring timing best
• Tolerates disturbance well

Winter Care:

• Maintain above 10°C (50°F)
• Reduce watering significantly
• No fertilization needed
• Maximum light exposure
• Good ventilation important

7. Landscape and Outdoor Cultivation

Landscape Value

• Excellent coastal specimen
• Wind-resistant palm
• Drought-tolerant option
• Blue-green color attractive

Design Applications

• Beachfront gardens
• Xeriscape designs
• Wind-exposed sites
• Salt-spray zones

8. Cold Climate Cultivation Strategies

Cold Hardiness

Better cold tolerance than most Hawaiian palms due to wind exposure adaptation.

Winter Protection

• Hardy to brief cold
• Protect below 10°C (50°F)
• Dry conditions improve hardiness
• Wind protection helpful

Hardiness Zone

• USDA 10a-11 standard
• Zone 9b in perfect coastal sites
• Mediterranean climates suitable

Winter Protection Systems and Materials

Marginal Areas:

• Coastal thermal mass helps
• Overhead protection
• Wind barriers critical
• Mulch root zone

Container Culture:

• Move to protection
• Reduce water drastically
• Maintain drainage
• Cool but frost-free

Establishment and Maintenance in Landscapes

Planting Techniques for Success

Site Selection:

• Full sun to light shade
• Wind exposure tolerated
• Excellent drainage essential
• Salt spray acceptable

Soil Preparation:

• Improve drainage extensively
• Add coarse amendments
• Slightly alkaline okay
• Avoid heavy clay

Planting Process:

• Plant high if drainage questionable
• Stake initially in windy sites
• Water to establish
• Mulch with gravel

Long-term Maintenance Schedules

Monthly (Growing Season):

• Check for pests
• Light watering if dry
• Remove damaged fronds

Quarterly:

• Fertilizer application
• Health assessment
• Prune only dead material

Annual:

• Soil testing
• Evaluate salt buildup
• Document growth
• Minimal care needed

Low Maintenance Overall: Very self-sufficient, Natural adaptations work, Less demanding than forest species