Hawaii: Landscaping

Types Of Native Trees Ideal For Windbreaks In Hawaii

· 8 min read

Windbreaks are a critical landscape element in Hawaii for protecting homes, farms, roads, and coastal infrastructure from prevailing trade winds, salt spray, and wind-driven erosion. Native trees and shrubs offer ecological advantages–adaptation to local climates, support for native wildlife, and reduced long-term maintenance–when compared with many exotic species. This article examines the best native and indigenous Hawaiian trees for windbreaks, explains design principles, and gives concrete, practical guidance for planning, planting, and maintaining effective living wind barriers across the islands.

Why choose native trees for windbreaks in Hawaii

Native and indigenous species are adapted to local soils, rainfall patterns, and climate stresses such as salt spray and wind. They support native pollinators and birds, require less fertilizer and pesticide in the long run, and reduce the risk of creating invasive stands that harm native ecosystems.
Using native species also increases resilience: a mixed stand of natives can maintain function if one species succumbs to disease or pests. In Hawaii, where unique pathogens (for example Rapid Ohia Death) and insects (wiliwili gall wasp) affect particular taxa, diversity reduces catastrophic loss.

Key windbreak design principles

Windbreak performance depends on height, orientation, density (porosity), and continuity. Keep these design rules in mind when choosing species and arranging plantings:

  • Choose a location oriented perpendicular to the prevailing wind direction (in Hawaii, usually the northeasterly trade winds).
  • Aim for a sheltered zone extending up to 10 times the mature height of the windbreak on the leeward side and about 1-2 times the height on the windward side. For a 10-meter tall windbreak, expect useful shelter up to roughly 100 meters downwind.
  • Target a porosity (leaf and branch openness) of about 40-60 percent. Solid, impermeable walls cause turbulence; very porous lines provide limited shelter. Many native hedges and mixed rows naturally approach the desirable porosity.
  • Use multiple rows of staggered plants (2-4 rows) for taller, durable windbreaks. Combine tall canopy trees, mid-story trees, and dense shrubs for layered protection.
  • Include species with different root depths and growth habits to stabilize soil and reduce risk of simultaneous failure.

Below is a shortlist of native or indigenous Hawaiian trees and shrubs commonly used or highly suitable for windbreaks. Each species description includes typical mature height, tolerance factors, growth rate, and practical notes.

  • Metrosideros polymorpha (Ohia lehua)
  • Acacia koa (koa)
  • Aleurites moluccanus (kukui / candlenut)
  • Thespesia populnea (milo / portia tree)
  • Pandanus tectorius (hala)
  • Cordia subcordata (kou)
  • Myoporum sandwicense (naio)
  • Hibiscus tiliaceus (hau)
  • Dodonaea viscosa (aalii / aalii)
  • Erythrina sandwicensis (wiliwili)

Metrosideros polymorpha (Ohia lehua)

Mature height and habit: highly variable–shrubby varieties 2-5 m; trees commonly 8-20 m.
Tolerance: very adaptable across elevations and soils, moderately wind- and salt-tolerant in coastal varieties, but highly vulnerable to Rapid Ohia Death (ROD) in areas where the pathogen is present.
Use: excellent as mid- to upper-canopy element in upland and mid-elevation windbreaks. Avoid planting exclusively with ohia where ROD is active; mix species.

Acacia koa (koa)

Mature height and habit: 15-25 m in good sites; open crown, fast growth on fertile soils.
Tolerance: not salt tolerant; prefers higher elevations and moderate to high rainfall.
Use: ideal for high-elevation windbreaks and shelterbelts on ranchlands where trees can reach full height; nitrogen-fixing benefits soil fertility.

Aleurites moluccanus (kukui)

Mature height and habit: 6-20 m, fast-growing with broad crown and drooping branches.
Tolerance: tolerant of coastal conditions and moderate salt spray; moderate drought tolerance once established.
Use: effective coastal windbreak component; produces edible nuts and supports cultural plantings.

Thespesia populnea (milo)

Mature height and habit: 6-12 m, dense rounded canopy.
Tolerance: very salt tolerant and tolerant of sandy soils and wind.
Use: excellent coastal windbreak species that forms a dense canopy and good visual screening.

Pandanus tectorius (hala)

Mature height and habit: often 3-10 m with prominent stilt roots and a layered crown.
Tolerance: extremely salt tolerant, excellent for dune and shoreline stabilization.
Use: ideal for first-line coastal protection; stilt roots help trap sand and reduce erosion.

Cordia subcordata (kou)

Mature height and habit: 6-12 m, rounded canopy, dense branching.
Tolerance: very salt tolerant; performs well on coasts and in wind-exposed sites.
Use: creates dense shelter and is also valued for flowers and cultural uses.

Myoporum sandwicense (naio)

Mature height and habit: 4-15 m, dense evergreen foliage.
Tolerance: tolerant of wind and salt spray; drought-tolerant when established.
Use: great mid-story tree in windbreaks; forms dense wind-sheltering foliage.

Hibiscus tiliaceus (hau)

Mature height and habit: 6-15 m, quick-growing with dense branching; coppices readily.
Tolerance: highly salt tolerant and excellent for hedgerows and coastal shelterbelts.
Use: can be managed as a thick hedge (coppiced) to provide nearly continuous, dense windbreaking.

Dodonaea viscosa (aalii)

Mature height and habit: usually 1-4 m as a shrub, sometimes reaching 4-6 m.
Tolerance: very tolerant of wind, salt, drought, and poor soils.
Use: superb choice for low hedges, filler rows, or as a sacrificial windward row. Fast to establish and useful for stabilizing slopes.

Erythrina sandwicensis (wiliwili)

Mature height and habit: 6-15 m with open, spreading crown; deciduous in dry season.
Tolerance: excellent drought tolerance for dry lowland windbreaks; lightweight wood and somewhat brittle.
Use: use in mixed plantings for nitrogen fixation and seasonal canopy; avoid sole reliance because of susceptibility to gall wasp and the open crown may allow some wind through unless planted densely.

Planting layout and spacing recommendations

Design your windbreak according to the desired function (full shelter, sand control, visual screening) and the mature height of the species you choose. A practical layout:

  1. Use 2-4 staggered rows perpendicular to prevailing winds.
  2. Place the tallest, longest-lived tree species in the middle or leeward rows so they form the upper canopy.
  3. Use denser shrubs and smaller trees on the windward and outer rows to create gradual wind deceleration and maintain porosity.
  4. Spacing: in-row spacings of 2-4 meters for shrubs and small trees; 3-6 meters for larger trees. Row spacing 3-6 meters apart, depending on mature crown widths.

Example mixed 3-row windbreak for coastal site (trade-wind exposed):

  • Windward row: hala or milo, 3-4 m spacing.
  • Middle row: kou and kukui alternated, 4-6 m spacing.
  • Leeward row: naio and hau, 3-4 m spacing (planted staggered relative to windward row).

This pattern yields layered canopy, mixed porosity, and redundancy.

Planting and maintenance best practices

Site preparation, establishment care, and ongoing maintenance determine long-term windbreak success.

  • Plant in the wet season or when you can provide irrigation for the first 1-2 years.
  • Use well-graded nursery stock: smaller stock establishes faster and is less prone to windthrow during early years; larger stock gives quicker shelter but requires more care.
  • Mulch heavily around new plants to retain moisture and suppress weeds. Native trees typically need less fertilizer, but apply a low-phosphorus balanced fertilizer if soils are very depleted; avoid over-fertilizing, especially with nitrogen where nitrogen-fixers like koa and wiliwili are present.
  • Water deeply and infrequently to encourage deep root development. In the first year, weekly to biweekly watering may be needed depending on site.
  • Prune selectively to encourage a single trunk where needed and to maintain lower branches for dense wind-sheltering. Coppicing hau creates very dense hedges.
  • Replace failed plants promptly to maintain continuity.

Disease, pests, and ecological considerations

Be aware of species-specific threats and plan for diversity:

  • Rapid Ohia Death (Ceratocystis) affects ohia; avoid monocultures of ohia in affected areas.
  • Wiliwili (Erythrina) gall wasp has decimated many wiliwili; do not rely solely on this species for wind protection.
  • Use local provenances (seed or planting stock) where possible to match local adaptations. Talk to island-based native nurseries about suitable ecotypes.
  • Avoid planting invasive exotics. Many introduced species (e.g., some fast-growing Australian acacias) spread aggressively; preference for natives reduces this risk.

Site-specific recommendations

Coastal beaches and dunes: choose hala, milo, kou, hau, and pandanus as front-line species for salt spray tolerance and sand trapping. Plant densest rows nearest the shore and provide continuous coverage.
Dry lowlands and ranch country: use wiliwili, aalii, and koa (on higher, less saline zones) mixed with hardy shrubs. Drought tolerance and deep rooting are priorities.
Upland and rainier slopes: include koa and ohi’a, with naio for mid-story. Ensure diversity for disease resilience and select ecotypes adapted to elevation and rainfall.

Practical one-acre windbreak example and timeline

Goal: Protect a one-acre vegetable field from northeasterly trade winds and reduce salt spray.
Year 0 (design):

  • Install a 3-row windbreak perpendicular to prevailing winds: windward hau (2.5 m spacing), middle row kou and kukui alternated (4 m spacing), leeward row naio and dodonaea for understory (2.5-3 m spacing).
  • Prepare holes, apply mulch ring, and install temporary tree guards if necessary against grazing.

Year 1-2 (establishment):

  • Irrigate weekly in dry spells, monitor for irrigation needs.
  • Replace any failed seedlings in the first planting season.

Year 3-5 (maturation):

  • Expect meaningful wind reduction within 3-5 years as trees grow to 3-6 meters. Thin and prune to maintain porosity and continuity.
  • After 5-10 years, shelter effect extends to tens of meters downwind; maintain understory for soil stabilization.

Final takeaways

  • Native and indigenous Hawaiian trees offer reliable, ecologically sound options for windbreaks when selected and arranged according to site conditions.
  • Design for height, porosity, and species diversity; mix coastal-tolerant species near the shore with drought- or upland-adapted trees inland.
  • Plant multiple rows, stagger plants, and plan for maintenance during the critical first 1-3 years.
  • Avoid monocultures to reduce risk from pests and disease, and source local stock when possible.

A well-designed native windbreak in Hawaii not only protects property and crops from wind and erosion but also enhances habitat, stabilizes soils, and contributes to the cultural and ecological integrity of the islands.