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© Emily Hjalmarson, some rights reserved (CC-BY-NC) · iNaturalist
Overview
Quercus vacciniifolia is a low-spreading evergreen shrub reaching 1-5 feet (0.3-1.5 m) tall and spreading 4-10 feet (1.2-3 m) wide, often forming dense mats or thickets several yards across. Stems much-branched, low and often partly buried in duff or rocky scree. Leaves alternate, oblong-elliptic to oval, 0.5-1.5 inches (1.3-4 cm) long with mostly entire (occasionally finely toothed) margins; upper surface gray-green, lower surface paler and finely hairy. Monoecious; male catkins yellow-green, 1-1.5 inches (2.5-4 cm) long, in June-July. Acorns 0.4-0.6 inch (10-15 mm) long in thin shallow cups, ripening over two seasons (biennial). Growth rate 1-3 inches (2.5-7.5 cm) per year at high elevation; thickets reach mature size in 30-50 years. Lifespan 100-200 years on stable subalpine sites. Foliage damaged below -20°F (-29°C); plants survive snow burial through winter and resprout from buried stems after fire or canopy loss.
Native Range
Native to high-elevation western North America from the southern Cascade Range of southern Oregon through the Sierra Nevada and Klamath Mountains of California. Found in subalpine forests, montane chaparral, rocky ridges, and granitic scree at 4,000-10,000 feet (1,200-3,000 m) elevation. Often co-occurs with Pinus contorta, Pinus albicaulis, Abies magnifica, and Arctostaphylos nevadensis.Suggested Uses
Used in alpine and rock garden plantings at 4-6 foot (1.2-1.8 m) spacing in zones 6-8 with cool summer climates. Restoration plantings in subalpine California and Oregon include this species for slope stabilization and wildlife cover. Container culture is impractical due to taproot sensitivity and slow growth.How to Identify
Appearance
Size & Dimensions
Height1' - 5'
Width/Spread4' - 10'
Reaches mature size in approximately 40 years
Colors
Bloom Information
Catkins appear June through July depending on elevation and snowmelt timing; bloom occurs 2-3 weeks after snowmelt at any given site. Total flowering 2-3 weeks per plant. Acorns require two growing seasons; nuts ripen September-October of the second year and disperse through autumn snowfall.Detailed Descriptions
Foliage Description
Gray-greenGrowing Conditions
Sun Requirements
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
Care & Maintenance
Care Guide
Plants establish from acorns sown directly in fall on rocky, well-drained soils. Cultivation outside the native range is uncommon and rarely succeeds at low elevations due to summer heat sensitivity. Mature plants require no supplemental water in zones 6-9 with cool summer temperatures. Container culture is generally short-lived (3-6 years) due to taproot disruption. Few pest pressures occur on natural high-elevation sites. Lifespan in cultivation has not been thoroughly documented.Pruning
Pruning is rarely needed in cultivated specimens; remove dead branches in late summer if visible at the surface of the mat. Hard pruning of mature thickets results in slow regrowth (1-3 inches / 2.5-7.5 cm per year). Layered stems often root where they touch soil, producing self-perpetuating thickets that need no intervention.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Maintenance Level
very lowContainer Growing
Minimum container size: 15 gallons