Broadleaf Deciduous Trees

Aesculus californica

California Buckeye

Sapindaceae

California Coast Ranges and Sierra Nevada foothills

At a Glance

TypeTree
HabitSpreading
FoliageDeciduous
Height10-20 feet (3-6 m)
Width15-30 feet (4.5-9 m)
Maturity10 years

Growing Zones

USDA Hardiness Zones

6 - 10
Zone 6
Zone 7
Zone 8
Zone 9
Zone 10
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Attracts Hummingbirds
Drought Tolerant
Fragrant (moderate)
Native to North America
Maintenancelow

Overview

Aesculus californica is a deciduous tree or large multi-stemmed shrub reaching 10–20 feet (3–6 m) tall with a broad, rounded crown spreading 15–30 feet (4.5–9 m) wide. Trunk bark is pale gray and smooth when young, developing shallow furrows with age. Palmate leaves have 5–7 leaflets, each 3–6 inches (8–15 cm) long, dark green above and pale below, with finely toothed margins. Unlike most deciduous trees, this species drops its leaves in midsummer during the dry season and enters dormancy from July through October, leaving bare branches. New foliage re-emerges in late winter to early spring, ahead of most deciduous trees. Fragrant white to pale pink flower spikes 4–8 inches (10–20 cm) long appear in May–June. Pear-shaped fruits 1–2 inches (2.5–5 cm) long follow, containing one to two large, glossy brown seeds. All parts are toxic if ingested.

Native Range

Native to California, occurring in the Coast Ranges, Sierra Nevada foothills, and interior valleys below 4,000 feet (1,200 m) elevation. Found in dry canyons, chaparral margins, and oak woodland understory where summer drought is pronounced.

Suggested Uses

Planted as a specimen tree in Mediterranean-climate gardens, native plant landscapes, and dry slopes. The summer dormancy period, when trees stand bare from July through October, suits siting where dormant structure is acceptable. Spread of 15–30 feet (4.5–9 m) requires at least 15 feet (4.5 m) clearance from structures and paved surfaces. Not suited to lawns or sites with summer irrigation.

How to Identify

Summer deciduousness — bare branches from July through October — distinguishes A. californica from other Aesculus species, which are dormant in winter. Palmate leaves with 5–7 narrow-elliptic leaflets emerge in late winter. Upright, cylindrical flower spikes are white to pale pink, appearing May–June. Pear-shaped fruits 1–2 inches (2.5–5 cm) long have a thick, leathery husk enclosing 1–2 smooth brown seeds.

Appearance

Size & Dimensions

Height10' - 20'
Width/Spread15' - 30'

Reaches mature size in approximately 10 years

Colors

Flower Colors

white
pink

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~5 weeks
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Spring
Blooms May through June in its native range; flowers open progressively from the base of the spike upward over 3–4 weeks. Total bloom period spans 4–6 weeks. Fragrant flowers attract hummingbirds and bees. Reliable bloom does not occur until the tree is 3–4 years established.

Detailed Descriptions

Flower Description

White to pale pink

Foliage Description

Dark green above, pale green below; absent July–October during summer dormancy

Growing Conditions

Sun Requirements

Full Sun
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)
357912
Soil Types
loamsandrocky
Drainage
well drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

5-10 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Established trees in climates matching the native California foothill range require no supplemental irrigation; plants tolerate 4–5 months without rain once established. In Pacific Northwest or eastern U.S. plantings with summer rainfall, drainage must be excellent to prevent root crown rot. Spider mites and aphids may appear on stressed plants in hot, dry conditions. Leaf litter and bare branches during summer dormancy require consideration in siting decisions. New foliage emerging in late winter may sustain frost damage during late-season cold snaps in zones 6–7. Trees planted in lawns receiving summer irrigation decline over 3–5 years.

Pruning

Pruning is performed in late fall after leaf drop or in early spring before new growth emerges. Remove crossing or structurally weak branches when young to establish a sound branch framework. No deadheading is required. Large branches pruned during the growing season bleed sap; dormant-season timing reduces this.

Pruning Schedule

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winterearly spring

Maintenance Level

low

⚠️ Toxicity Warning

Toxic to pets and humans