Island ironwood, though cultivated widely, occurs natively only on the California Channel Islands. The widespread horticultural subspecies, aspleniifolius (Santa Cruz Island ironwood), has opposite, fern-like divided leaves. In contrast, subspecies floribundus (Santa Catalina Island ironwood) has undivided leaves and occurs only on Santa Catalina Island. The sinuous bark peels with age, exposing smooth, cinnamon-colored new bark. Flat-topped clusters of white flowers are produced in spring and linger on the tree for months.

Native Range: California Channel Islands

Horticultural use: Screen

Schoolyard Use: This tree has fern-like, deeply lobed leaves that can be used to teach about leaf morphology and plant adaptation. The leaves are evergreen, making it a good subject for lessons on different leaf life cycles. Its clusters of white flowers attract pollinators, offering a practical example of plant-pollinator interactions. The tree’s bark peels in strips, which can be used to discuss tree growth and bark functions.

Tree Shape: Conical or Rounded
Foliage Type: Deciduous
Maximum Tree Height: 40 feet
Canopy Width: 15-20feet
Growth Rate: ~24in/year
Leaf Arrangement and Form: Opposite and Pinnately Compound
Leaf Shape: Oblong
Leaf Color: Dark Green
Fall Color: No
Flowers: Showy
Flower Color: White
Flower Time: Summer
Fruit Size and Color: Small Brown Capsule
Fruiting Time: Fall
Bark Color: Striking, Light Gray or Red Brown
Bark Texture: Exfoliating, Smooth and Striated
Litter Type: Dry Fruit

Recommended Planting Area: 4′ to 7′
Water Use Rating: Low
Sunset Climate Zone: 14 – 17 and 19 – 24
Soil Texture: Loam or Sand
Soil pH: Very Acidic to Slightly Alkaline
Salt Tolerance: High
Schoolyard Trees: Yes
Shade Tolerance: No

Branch Strength: Strong
Root Damage Potential: Moderate
Potential health issues: None Known
Biogenic Emissions: Low
Wildlife Interactions: Attracts Birds
Disease and Pest Susceptibility: Phytophthora
Utility Friendly: No