Quercus sadleriana, Sadler's Oak
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Broadleaf Evergreen Shrubs

Quercus sadleriana

Sadler's Oak

Fagaceae

Klamath-Siskiyou region of northwestern California and southwestern Oregon; mixed conifer forests and serpentine chaparral at 2,000–7,000 feet (600–2,100 m)

At a Glance

TypeShrub
HabitSpreading
FoliageEvergreen
Height2–6 feet (0.6–1.8 m)
Width4–10 feet (1.2–3 m)
Maturity8 years

Growing Zones

USDA Hardiness Zones

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

Key Features

Attracts Pollinators
Drought Tolerant
Native to North America
Maintenancevery low

Overview

Quercus sadleriana is a rare, rhizomatous, evergreen shrub oak native to the Klamath-Siskiyou region of northern California and southern Oregon. Plants reach 2–6 feet (0.6–1.8 m) tall and spread indefinitely by rhizomes, forming dense colonies in the wild; individual stems grow slowly, 4–8 inches (10–20 cm) per year. The habit is suckering and colony-forming. Leaves are 2.5–4 inches (6–10 cm) long, oval to oblong, dark green above and paler beneath, with 8–15 prominent parallel secondary veins terminating in mucronate (sharp-pointed) teeth along the margins, closely resembling chestnut (Castanea) leaves. Stipules are persistent, golden-silky, up to 0.6 inch (15 mm) long — a distinctive diagnostic feature. Acorns are small, produced after several years. The species is considered rare and of conservation concern within its limited native range. It performs poorly in hot, dry conditions outside its native fog-influenced range.

Native Range

Quercus sadleriana is native to the Klamath-Siskiyou region of northwestern California (Del Norte, Siskiyou, and Trinity counties) and adjacent southwestern Oregon, typically in mixed conifer forests and serpentine chaparral at elevations of 2,000–7,000 feet (600–2,100 m).

Suggested Uses

Planted in native plant gardens, woodland understory plantings, and conservation-oriented landscapes where the rhizomatous, colony-forming habit can be accommodated, spaced 4–6 feet (1.2–1.8 m) apart. The chestnut-like foliage and regional native origin make this a botanically significant specimen in collections focused on Pacific Northwest and Klamath flora. Best suited to partly shaded, well-drained sites; not suitable for irrigated lowland gardens.

How to Identify

Quercus sadleriana is identified by its low, suckering, colony-forming habit; oval to oblong leaves 2.5–4 inches (6–10 cm) long with prominent parallel veins and mucronate teeth closely resembling chestnut leaves; dark green upper surface, paler beneath; and persistent golden-silky stipules up to 0.6 inch (15 mm) long at the base of each leaf. Distinguished from all other western oaks by the combination of chestnut-like leaf shape, persistent golden stipules, and rhizomatous shrub habit.

Appearance

Size & Dimensions

Height2' - 6'
Width/Spread4' - 10'

Reaches mature size in approximately 8 years

Colors

Flower Colors

yellow green

Foliage Colors

dark green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~3 weeks
J
F
M
A
M
J
J
A
S
O
N
D
Spring
Male catkins are pendulous, 1–2 inches (2.5–5 cm) long, yellow-green, releasing pollen in April–May. Female flowers are inconspicuous, at leaf axils. Acorns mature in the second year, small, enclosed one-third to one-half in a scaly cup.

Detailed Descriptions

Flower Description

yellow-green (male catkins)

Foliage Description

dark green above, paler beneath

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 4-10 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 Range5.0 - 7.0(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

Water weekly during the first two growing seasons; established plants are drought-tolerant in their native range but perform best with some summer moisture in cultivation outside the Klamath fog belt. Prefers well-drained to dry soils, tolerating serpentine substrates better than most plants. Best in partial shade to full sun; declines in hot, exposed lowland positions. The rhizomatous, colony-forming habit means plants spread slowly over time — allow 4–6 feet (1.2–1.8 m) of spreading room.

Pruning

No pruning required. The natural suckering habit develops without intervention. Individual stems can be removed at the base to limit spread. Remove dead stems at any time.

Maintenance Level

very low

⚠️ Toxicity Warning

Non-toxic