Umbellularia californica (California Laurel)

California Laurel – Umbellularia californica: An In-depth Look

Umbellularia californica, commonly known as California Laurel, Oregon Myrtle, or California Bay, is a versatile broadleaf evergreen tree or shrub native to the Pacific coastal regions of southwestern Oregon and California. Belonging to the laurel family (Lauraceae), this aromatic species is prized for its glossy foliage, fragrant flowers, culinary applications, and richly grained wood. Its adaptability to various soils, drought tolerance, and ecological value make it an important plant in natural landscapes and cultivated settings.

Though often compared to Bay Laurel (Laurus nobilis), California Laurel is a distinct species, known for its stronger aroma and role in regional ecosystems. It is the only species in its genus, Umbellularia.

Native Range

California Laurel is native to the western United States and parts of northwestern Mexico. Its natural range extends from the Klamath and Siskiyou Mountains in southwest Oregon, through California’s Coast Ranges, Sierra Nevada foothills, and portions of the Central Valley, reaching as far south as San Diego County. It also occurs in the northwestern regions of Mexico. This versatile tree thrives in a variety of habitats, including moist canyons, streambanks, and shaded hillsides, at elevations up to approximately 5,200 feet (1,600 meters).

Plant Type and Habit

This evergreen species varies in form from a multi-stemmed shrub to a large upright tree. In moist areas, it can grow tall and dense with a broad, rounded crown, while in dry environments, it remains smaller and more shrub-like. It can also form dense thickets via root sprouts.

Size

California Laurel typically grows 30 to 80 feet tall (9 to 24 meters), with some specimens reaching up to 100 feet (30 m) in ideal conditions. In exposed or arid locations, it may remain under 20 feet tall (6 meters).

The spread can range from 18 to 30 feet for trees, while shrub forms are generally smaller.

California Laurel is slow to establish but can grow medium to fast once established. It may grow about 1 to 2 feet (30-60 cm) per year under optimal conditions.

Lifespan

With proper conditions, California Laurel can live for several decades to over 100 years. Older trees often develop multiple trunks and dense crowns.

Flowers

In early to mid-spring, California Laurel produces delicate clusters of creamy-white to pale yellow flowers arranged in short-stemmed umbels of 6 to 10 blossoms. Nestled in the leaf axils, each bloom is about 0.6 inches (1.5 cm) across. Though modest in appearance, their sweet, spicy fragrance attracts bees and other early-season pollinators.

Fruits

By fall, the tree bears distinctive, olive-like drupes—round to elliptical fruits about 0.75 inches (2 cm) in diameter. Starting green, they ripen to a yellowish-green or rich purple. Inside lies a single, hard seed, known as the “bay nut,” once roasted and eaten by Native American tribes. With its avocado-like look and earthy aroma, the fruit adds character and ecological value.

Foliage

California Laurel boasts handsome, evergreen leaves that are leathery and lance-shaped, measuring 1 to 4 inches (2.5–10 cm) long and 0.5 to 1 inch (1.2–2.5 cm) wide. Arranged alternately, the upper surface is glossy dark green, while the underside is paler and slightly hairy. When crushed, the leaves release a sharp, spicy-camphor scent. Though sometimes used as a substitute for Bay Laurel (Laurus nobilis) in cooking, their more intense flavor requires careful use.

Bark

Young bark is smooth and grayish-brown, maturing to scaly, reddish-brown tones. The trunks and branches may become deeply furrowed with age, contributing to the tree’s rugged character.

Wood

California Laurel is highly prized as an ornamental and street tree along the West Coast and is considered the most valued hardwood species in the Western United States. Its handsome, light brown wood—often accented with darker, streaky figuring—is widely used for veneer, fine furniture, cabinetry, and interior paneling and trim.

Hardiness

California Laurel is hardy in USDA zones 7–9. It tolerates cold down to 10°F (-12°C) and performs well in coastal and interior climates with cool winters and dry summers.

Uses

• Ornamental: California Laurel is prized for its dense, evergreen foliage and aromatic qualities, making it a striking addition to parks, large gardens, and naturalistic landscapes.
• Woodworking: Commercially known as myrtlewood, its fine-grained, richly colored wood is highly valued for cabinetry, furniture, veneers, turned bowls, and even musical instruments like guitars.
• Culinary: The leaves are used as a robust seasoning, similar to Mediterranean bay (Laurus nobilis), but stronger. They are used sparingly to flavor stews, soups, and sauces.
• Medicinal: Native American tribes traditionally used the leaves and extracts for treating headaches, colds, respiratory issues, and minor skin ailments. Poultices and teas were common applications.
• Erosion Control: With a deep and spreading root system, California Laurel is ideal for stabilizing banks, slopes, and riparian zones. It thrives in moist soils and helps prevent erosion in creekside settings.
• Shade and Screening: Its dense canopy and evergreen habit make it excellent for creating year-round privacy screens, windbreaks, and shade trees, especially in large landscapes or naturalized areas.
• Coastal Gardens: Moderately tolerant of salt spray and coastal winds, this tree is a strong performer in marine environments when protected from direct salt exposure.
• Pond and Stream Margins: Naturally found along watercourses, it grows well in moist soils near ponds, streams, and other wetland edges, contributing to habitat restoration and visual appeal.
• Slopes and Banks: Its adaptability and structural root system allow it to anchor steep areas, helping reduce runoff and soil loss on hillsides and embankments.
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Wildlife Value

California Laurel supports a wide array of wildlife. Its fragrant flowers attract pollinating insects, especially bees and flies. Birds, squirrels, and small mammals—including silver gray squirrels, dusky-footed woodrats, California mice, and Steller’s jays—feed extensively on the seeds.

The dense evergreen foliage provides excellent cover and nesting sites.

The tree also serves as a larval host for several moth species. In early spring, deer and goats browse the young shoots when aromatic compounds are at their lowest. Hogs are known to consume both seeds and roots.

Drought and Salt Tolerance

Once established, California Laurel is drought-tolerant, requiring minimal supplemental irrigation. It also exhibits moderate salt tolerance, making it suitable for coastal environments.

Toxicity

The leaves contain umbellulone, a volatile compound that can cause headaches or allergic reactions in sensitive individuals. Though sometimes used in cooking, the strong oils may pose health risks if consumed in large amounts. Always use it with caution.

Deer and Rabbit Resistance

California Laurel is generally deer-resistant due to its strong scent and tough, leathery leaves. However, young sprouts may be browsed by deer or goats in early spring.

Invasiveness

California Laurel is not considered invasive but can spread aggressively via suckers in suitable conditions.

Benefits and Drawbacks of California Laurel

Benefits

• Evergreen Appeal: Year-round foliage provides structure, shade, and privacy.
• Aromatic Foliage: Leaves emit a distinctive, spicy fragrance when bruised or crushed.
• Wildlife Habitat: Offers food and shelter for birds, insects, and small mammals.
• Low Maintenance: Drought-tolerant, pest-resistant, and adaptable to various soils.
• Soil Stabilization: Ideal for erosion-prone sites, such as streambanks and slopes.
• Hardwood Value: Myrtlewood is highly prized for its strength, color, and figure.
• Cultural Significance: Used historically in food, medicine, and ceremonial practices by Indigenous peoples.

Drawbacks

• Strong Aroma: Can trigger headaches or allergic reactions in sensitive individuals.
• Sudden Oak Death Host: Serves as a reservoir for Phytophthora ramorum, which threatens oak populations.
• Allelopathic Effects: Releases terpenes that inhibit understory plant growth.
• Wind and Snow Damage: Susceptible to breakage and toppling in storms.
• Fruit Litter: Drupes can create messes underfoot when dropped.

How to Grow and Care for California Laurel

Planting

• Location: Choose a spot with full sun to partial shade.
• Soil: Prefers well-draining, fertile soils with a slightly acidic to neutral pH. It can tolerate a variety of soil types but performs best in nutrient-rich conditions.
• Planting Time: Plant in fall or early spring to allow roots to establish before summer heat.
• Spacing: Space 20–40 feet apart for trees; 8–15 feet apart for hedging or screens.
• Mulching: Apply mulch around the base to retain moisture and suppress weeds.

Watering

• Young Plants: Water regularly during the first year to promote root establishment.
• Established Plants: Requires little supplemental irrigation. Water deeply during prolonged droughts.
• Avoid Overwatering: Ensure proper drainage to prevent root rot.

Fertilization

• Fertilize in early spring with a balanced, slow-release fertilizer if growth is weak.
• In fertile soils, additional feeding is usually unnecessary.

Pruning

• Timing: Prune in late winter or early spring before new growth begins.
• Maintenance: Remove dead, damaged, or crossing branches. Light pruning maintains shape.
• Severe Pruning: Tolerates hard pruning; resprouts readily from trunk and roots. Remove suckers as they emerge to maintain a desired form

Winter Care

• Generally hardy in USDA zones 7–9. Mulch in colder zones to protect roots.
• Protect young trees from severe frost or wind desiccation.

Container Growing

• Size: Choose large containers with excellent drainage.
• Soil: Use a well-draining potting mix with added organic matter.
• Watering: Keep soil evenly moist but not soggy.
• Pruning: Regular pruning maintains size and shape in containers.
• Overwintering: Move containers to sheltered locations during severe cold.

How to Propagate California Laurel

California Laurel can be propagated by both seed and semi-hardwood cuttings, although patience is required due to its slow growth rate.

Seed Propagation

• Harvesting: Collect ripe fruits (drupes) in fall when they turn purple or yellow-green. Remove the fleshy outer layer to reveal the hard seed inside.
• Preparation: Scarify or lightly crack the hard seed coat to improve germination. Stratification (chilling) at 37–41°F (3–5°C) for 60–90 days helps break dormancy.
• Sowing: Sow in a well-draining medium such as a mix of peat and sand. Keep moist and maintain temperatures between 60–70°F (15–21°C). Germination may take several weeks to months.

Cuttings

• Timing: Take semi-hardwood cuttings in late summer, when the stems are firm but still pliable.
• Preparation: Cut 4–6 inch (10–15 cm) segments, remove the lower leaves, and dip the cut end in rooting hormone.
• Rooting: Plant in a sterile, moist propagation mix and cover with plastic or place in a humidity dome. Keep warm and out of direct sunlight until rooted, which may take 6–10 weeks.

Transplanting

Once seedlings or rooted cuttings have developed strong root systems, transplant them into individual containers. Grow them on for 1–2 years before planting out in the landscape.

Pests and Diseases of California Laurel

Common Pests

• Thrips: Can cause leaf curling and stippling. Control with neem oil or insecticidal soap.
• Leafminers: Larvae that tunnel through leaves. Prune affected areas and apply organic treatments.
• Scale insects: Hard-shelled insects that feed on sap. Scrape off or apply horticultural oil.
• Borers: May infest weakened trees. Maintain tree vigor to prevent damage.

Common Diseases

• Sudden Oak Death: Caused by Phytophthora ramorum, for which California Laurel is a known host.
• Root rot: Associated with poorly drained soils. Improve drainage to prevent infection.
• Anthracnose: Causes leaf spotting and dieback. Remove infected leaves and apply fungicide if needed.
• White Rot: A wood-decay fungus affecting older or injured trees.

Preventative Measures

• Choose Healthy Stock: Start with disease-free nursery plants.
• Improve Air Circulation: Space plants adequately to reduce humidity and fungal issues.
• Water at Base: Avoid wetting foliage to prevent leaf diseases.
• Clean Tools: Disinfect pruning tools to prevent disease spread.