Myrica faya (Faya): Complete Tree Growing Guide
Myrica faya
Myrica faya (Faya)
1. Introduction & Taxonomy
Faya has colonized volcanic slopes across the Macaronesian islands for millennia, its nitrogen-fixing roots transforming barren lava fields into fertile forest. This resilient evergreen thrives in the harsh, fog-drenched laurel forests of the Azores, Madeira, and Canary Islands, though its invasive behavior in Hawaii has earned it infamy. For temperate maritime gardens and challenging sites, it offers unmatched toughness and ecological value, provided its aggressive tendencies are managed. Myrica faya is notable for growing to 10 m tall.
An evergreen shrub or small tree usually to about 10 m tall, native to evergreen forests at mid altitudes on the Azores, Madeira, and the Canary Islands. Myrica faya is easily grown in most warm temperate climates and has escaped cultivation in southern Portugal and on Hawaii, where it is considered a weed.
Taxonomic Classification
Habitat and Distribution
Myrica faya is native to evergreen forests at mid altitudes on the Azores, Madeira, and the Canary Islands. The genus Myrica is characterised by its tree growth form.
Botanical Note: Trees are the dominant life form in most terrestrial ecosystems, providing structure, shade, food, and habitat for countless organisms. With approximately 73,000 known tree species worldwide, they represent a remarkable diversity of evolutionary strategies — from the ancient gymnosperms (conifers, ginkgos) that dominated Mesozoic forests to the angiosperms (flowering trees) that radiated spectacularly in the Cretaceous and now constitute the majority of tree species. Trees have independently evolved in many plant lineages, demonstrating the immense adaptive advantage of the woody, perennial growth form.
Native Range & Distribution Map
The map below shows the native range and notable cultivation regions for Myrica faya.
2. Morphology & Growth Form
Crown Form & Architecture
Myrica faya typically develops a rounded, dome-shaped crown with a relatively short trunk relative to the canopy spread. This balanced form provides excellent shade and a pleasing natural silhouette.
Key Characteristics
- Height: 4-10 m
- Growth Habit: Tree
- Growth Rate: Moderate under optimal conditions
- Leaf Type: Evergreen
Tree Biology Insight: Trees achieve their towering stature through secondary growth — the production of wood (secondary xylem) and bark (secondary phloem) by the vascular cambium. Each annual growth ring records a year of the tree's life, with ring width reflecting growing conditions. The world's tallest trees (Sequoia sempervirens, over 115 m) and most massive organisms (Sequoiadendron giganteum, over 1,400 tonnes) are both trees, demonstrating the extraordinary potential of woody plant architecture.
Notable Adaptations
The tree grows steadily to 6-12 meters, developing a dense, rounded crown with narrow, lanceolate leaves that are glossy dark green above and paler beneath. Bark is smooth and gray-brown, becoming slightly roughened with age, while the wood is moderately hard and historically used for small implements and fuel. The roots form symbiotic associations with nitrogen-fixing Frankia bacteria, enriching poor soils and facilitating forest succession.
3. Reproduction & Propagation
The primary propagation methods for Myrica faya: Seed, cuttings, or grafting.
Propagating Myrica faya
Dioecious trees produce separate male and female catkins in spring, with wind pollination requiring both sexes for fruit production. Female trees develop small, fleshy drupes approximately 5-7 mm in diameter that ripen from green to dark purple, containing a single seed. Birds eagerly consume the fruit, dispersing seeds widely and contributing to the tree's aggressive naturalization in favorable climates.
Myrica faya can be propagated from seed. Collect ripe fruit or seed pods and extract seeds. Many tree seeds have physical or physiological dormancy requiring scarification (nicking or soaking in hot water) or cold stratification before germination. Sow in a well-draining seed mix, keep moist, and provide warmth (20–25°C) and light.
Vegetative Propagation
- Cuttings: Take semi-hardwood cuttings in summer or hardwood cuttings in winter. Treat cut ends with rooting hormone and place in a well-draining medium (perlite/peat mix) under high humidity. Many tree species root readily from cuttings.
- Grafting: Grafting is widely used for fruit trees, ornamental cultivars, and species difficult to root from cuttings. Common techniques include whip-and-tongue, cleft, and bud grafting onto compatible rootstock.
- Air Layering: Useful for species difficult to root from cuttings. Wound a branch, apply rooting hormone, wrap with moist sphagnum and plastic, and wait for roots to develop (usually 2–6 months).
Tree Reproduction Biology: Flowering trees (angiosperms) employ diverse pollination strategies: wind (many temperate hardwoods like oaks, birches, and elms), insects (most fruit trees, magnolias), birds (Erythrina, some Eucalyptus), and bats (baobab, kapok). The evolution of enclosed seeds within fruits has been a major driver of angiosperm diversification and their symbiotic relationships with animal seed dispersers.
Propagation Tips: (1) Tree seeds are often short-lived — sow as fresh as possible. (2) Grafted trees produce fruit or flowers years earlier than seedlings. (3) Many tropical trees germinate best at 25–30°C with high humidity. (4) Temperate deciduous trees often require 60–120 days of cold stratification. (5) Some seeds (legumes, palms) benefit from scarification before sowing.
4. Cultivation & Planting
Plant in full sun to partial shade with 5-8 meter spacing, as the tree develops a moderately wide crown and suckers freely from the roots. It thrives in acidic, well-drained soils but tolerates poor, infertile substrates where most trees fail, making it ideal for reclamation sites. Propagation from seed is straightforward, though controlling root suckers and seedling volunteers requires vigilance in regions where it may become invasive.
Soil Requirements
Myrica faya grows best in deep, fertile, well-drained soil with a loamy texture. Most trees are adaptable to a range of soil pH values (5.5–7.5). Amend heavy clay soils with organic matter and grit to improve drainage and aeration.
Watering
Water regularly during establishment (first 2–3 years after planting). Once established, most trees develop deep root systems that access subsoil moisture. Supplemental irrigation during prolonged drought improves growth and reduces stress.
Light Requirements
Full sun to partial shade, depending on species. Most trees produce their best form, flowering, and fruiting in full sun. Some understorey species tolerate or prefer partial shade.
Temperature & Hardiness
- Optimal Growth: 15–30°C (59–86°F)
- Minimum Tolerance: -12°C (10°F)
- USDA Hardiness: Zones 8-11
Planting Guidelines
- Timing: Plant bare-root trees in late autumn to early spring during dormancy. Container-grown trees can be planted year-round but establish best when planted in autumn.
- Spacing: Allow adequate space for the mature canopy spread. Crowding leads to poor form, increased disease pressure, and competition for light and water.
- Depth: Plant at the same depth as in the nursery container. Do not bury the root flare — this is a common planting error that leads to slow decline.
- Staking: Stake only if necessary (exposed windy sites), and remove stakes after 1–2 years to encourage trunk strengthening.
Common Planting Mistake: Planting too deep is the most common cause of tree failure. The root flare (where the trunk widens at the base) must be visible at or slightly above soil level. Deep planting suffocates roots, promotes collar rot, and leads to girdling roots that can kill the tree years later.
Seasonal Care Calendar
Follow this season-by-season guide for optimal care timing throughout the year.
🌱 Spring (March–May)
Apply compost or slow-release fertilizer if growth is desired, though established trees rarely need feeding. Remove suckers and prune lightly to shape. Monitor for new seedlings if fruit was produced and remove volunteers before they establish.
☀️ Summer (June–August)
Water young trees during extended droughts, though established specimens are remarkably drought-tolerant. Continue sucker removal and watch for seedling volunteers. Harvest fruit from female trees if you wish to use it or prevent seed dispersal.
❄️ Winter (December–February)
Prune structural issues during dormancy, removing dead, damaged, or crossing branches. Protect young trees from harsh winds with shelters or windbreaks in exposed locations. Continue vigilance for sucker growth even during the dormant season.
5. Diseases & Pests
Myrica faya, like most trees, is generally resilient when growing in appropriate conditions. Most disease problems arise from environmental stress, poor planting, or mechanical damage.
Major Diseases
Root Rot (Phytophthora, Armillaria)
Root rot is the most devastating tree disease complex. Phytophthora thrives in waterlogged soils and attacks fine roots, while Armillaria (honey fungus) produces distinctive mushrooms at the base of infected trees. Prevention: ensure good drainage, avoid overwatering, and do not pile soil or mulch against the trunk.
Canker Diseases
Canker-forming fungi (Nectria, Cytospora, Botryosphaeria) invade through wounds, pruning cuts, or stressed tissue. Sunken, discoloured bark areas expand and can girdle branches or trunks. Prune out infected wood well below the canker margin. Prevent by avoiding bark injuries and maintaining tree vigour.
Leaf Spot / Anthracnose
Fungal leaf spots and anthracnose cause browning, spotting, and premature leaf drop. Usually more cosmetic than life-threatening. Improve air circulation, rake and destroy fallen leaves, and apply fungicides in severe cases.
Common Pests
- Borers — Wood-boring beetles and clearwing moths attack stressed trees. Maintain vigour through proper watering, mulching, and avoiding bark damage.
- Defoliators — Caterpillars, sawfly larvae, and leaf beetles can severely defoliate trees. Healthy trees usually recover from a single defoliation event. Apply Bt (Bacillus thuringiensis) for caterpillar control.
- Scale Insects & Aphids — Sap-sucking insects that weaken trees and produce honeydew, leading to sooty mould. Treat with horticultural oil or systemic insecticide.
- Spider Mites — Cause stippled, bronzed foliage in dry conditions. Increase humidity and apply miticide.
Integrated Pest Management: (1) Select species and cultivars adapted to your climate and soil. (2) Maintain tree health through proper watering, mulching, and avoiding mechanical damage. (3) Monitor regularly for early signs of pest or disease. (4) Preserve beneficial insects (ladybirds, lacewings, parasitic wasps). (5) Use targeted treatments rather than broad-spectrum pesticides. (6) Prune during the correct season to minimise disease entry.
Additional Disease Notes
The tree is remarkably disease and pest-resistant, with few documented issues even in introduced ranges. Root rot may occur in poorly drained, waterlogged soils, though the tree generally tolerates challenging conditions. Browsing by deer or livestock can damage young trees, requiring protection until establishment.
6. Pruning & Maintenance
Prune lightly to shape young trees and remove suckers from the base if a single-trunked form is desired, as the tree naturally develops multiple stems. Thin the canopy if it becomes overly dense, improving air circulation. Regular removal of root suckers is necessary to prevent the tree from forming thickets in garden settings.
Pruning Principles
- Formative Pruning: Establish a strong central leader and well-spaced scaffold branches in the first 5–10 years. Remove co-dominant stems, crossing branches, and low branches that will need removal later.
- Maintenance Pruning: Remove dead, diseased, damaged, and crossing branches. Never remove more than 25% of the live crown in a single year.
- Timing: Prune deciduous trees during dormancy (winter) for major structural work. Summer pruning can be used for light corrective work and to slow vigorous growth.
Mulching
Apply a 5–10 cm layer of organic mulch (wood chips, bark, leaf mould) around the base of the tree, extending to the drip line if possible. Keep mulch 10–15 cm away from the trunk to prevent collar rot. Mulch conserves moisture, moderates soil temperature, suppresses weeds, and improves soil biology as it decomposes.
Fertilisation
Young trees benefit from a balanced slow-release fertiliser (NPK 10-10-10 or similar) applied in early spring. Established trees in good soil rarely need fertilisation. Avoid high-nitrogen fertilisers that promote soft, disease-susceptible growth.
Pruning Safety: Trees are large organisms and pruning above head height involves significant risk. For any pruning that requires a ladder, elevated work platform, or chainsaw, hire a certified arborist (ISA-certified or equivalent). Improper pruning — especially topping, flush cuts, and lion-tailing — causes long-term structural damage and decay that can make trees hazardous.
7. Landscape & Agroforestry
The species excels on harsh, infertile sites where soil improvement is needed, such as eroded slopes, mine spoils, or newly reclaimed land. Its nitrogen-fixing ability and dense evergreen foliage make it valuable for windbreaks, screens, and wildlife habitat in maritime climates. In regions where it is invasive (particularly Hawaii), avoid planting and participate in removal efforts to protect native ecosystems.
Landscape Applications
- Specimen Tree: Plant as a focal point in lawns, parks, or large gardens where its form can be fully appreciated
- Shade Tree: Provides cooling summer shade for buildings, patios, and outdoor living areas. A single large shade tree can reduce cooling costs by 20–40%.
- Street / Avenue Tree: Suitable for urban planting in streets, plazas, and parks where space allows for mature canopy development.
- Wildlife Habitat: Provides nesting sites for birds, food sources (seeds, fruit, nectar), and shelter for diverse wildlife
Companion Planting
Create effective plant communities by combining with:
- Understorey Trees — Smaller trees and large shrubs that thrive beneath the canopy
- Ground Covers — Shade-tolerant perennials, ferns, and bulbs for the forest floor layer
- Climbers — Mature trees can support non-damaging climbers like clematis or jasmine
- Bulbs — Spring-flowering bulbs beneath deciduous trees take advantage of light before leaf emergence
Ecosystem Services: A single mature tree provides extraordinary environmental benefits: absorbing 20–50 kg of CO₂ annually, releasing oxygen for 2–4 people, intercepting thousands of litres of stormwater, filtering air pollutants, reducing ambient temperature by 2–8°C through transpiration, and supporting hundreds of species of insects, birds, and other organisms. Trees are among the most cost-effective environmental investments any landowner can make.
8. Climate Adaptation & Hardiness
Hardy to approximately -10°C for brief periods, the tree thrives in USDA zones 8-10 with oceanic or Mediterranean climates. In colder zones, it may survive in sheltered coastal locations but suffers from severe winter cold or desiccating winds. Container culture is possible for smaller specimens, overwintered in cool greenhouses in marginal zones.
Hardiness Thresholds
- USDA Zones: 8-11
- Minimum Survival Temperature: -12°C (10°F)
Cold Protection Strategies
- Site Selection: Plant in sheltered positions with good air drainage (avoid frost pockets). South- or west-facing walls provide radiated warmth and wind protection.
- Mulching: A deep mulch layer (10–15 cm) over the root zone insulates roots from freezing temperatures and reduces soil temperature fluctuations.
- Wrapping: Protect the trunk and scaffold branches of borderline-hardy trees with horticultural fleece or hessian during severe cold events. This is especially important for young trees during their first few winters.
- Container Growing: Trees in containers can be moved to frost-free locations for winter. Use large, insulated containers to protect roots from freezing.
Heat & Drought Adaptation
Many trees develop deep taproots and extensive lateral root systems that access water well beyond the canopy drip line. Drought adaptations include deciduousness (shedding leaves to conserve water), thick bark, small or waxy leaves, and the ability to close stomata rapidly during water stress.
Climate Change Consideration: As climate zones shift, tree species suitable for a given location are changing. When planting trees for the long term (50–200+ years), consider selecting species or provenances adapted to projected future conditions rather than current ones. Diversifying species selection across a property or community reduces the risk of catastrophic losses from any single pest, disease, or climate event.
9. Ethnobotany & Cultural Significance
Macaronesian islanders historically used the fruit to produce a fermented beverage and dye, while the wood provided fuel and small tools. The tree's nitrogen-fixing ability was recognized and valued for improving agricultural soils long before the scientific mechanism was understood. In Hawaii, it has become the target of extensive control efforts to protect native ecosystems from nitrogen enrichment that favors invasive species.
Conservation Note: Many tree species face threats from deforestation, climate change, and overexploitation. Trees are keystone organisms in terrestrial ecosystems, providing habitat for countless species, sequestering carbon, regulating water cycles, and stabilising soils. By cultivating Myrica faya and supporting sustainable forestry practices, you contribute to the conservation of global tree diversity. Over 30% of the world's tree species are threatened with extinction.
Frequently Asked Questions
Is Faya invasive in my area?
It is highly invasive in Hawaii and potentially problematic in other mild, humid climates with native ecosystems sensitive to nitrogen enrichment. Check local invasive species lists and avoid planting in ecologically sensitive areas or regions with similar climates to Hawaii.
How do I control root suckers?
Regularly cut or mow suckers at ground level, or apply selective herbicide to cut stumps to prevent regrowth. Installing root barriers around the tree during planting can limit sucker spread in garden settings.
Can it improve poor soils?
Yes, its nitrogen-fixing root nodules enrich the soil over time, making it valuable for reclamation projects and preparing sites for more demanding species. However, this same trait drives its invasiveness in some ecosystems.
Do I need both male and female trees for fruit?
Yes, as the species is dioecious, both sexes must be present for pollination and fruit production. If fruit is undesirable (to reduce invasiveness), plant only male trees.
Why are my leaves yellowing?
While the tree tolerates poor soils, extremely alkaline conditions or waterlogging can cause stress and chlorosis. Ensure proper drainage and verify soil pH is acidic to neutral for best performance.
Summary & Key Takeaways
Faya is a nitrogen-fixing evergreen from Macaronesia, thriving in poor, harsh maritime conditions where it improves soil and provides wildlife habitat. Hardy to zone 8 but invasive in Hawaii, it requires careful management to balance ecological benefits with potential for unwanted spread.
Key Points to Remember:
- Propagation: Seed, cuttings, grafting
- Light: Full sun to partial shade depending on species
- Soil: Deep, fertile, well-drained
- Water: Regular during establishment, drought-tolerant once mature
- Hardiness: USDA Zones 8-11, minimum -12°C (10°F)
- Key Threat: Root rot from poor drainage — ensure well-drained planting site