Pinus flexilis
limber pine
Overview
Pinus flexilis, limber pine, is a slow-growing, long-lived conifer of the mountains of western North America, reaching 30-50 feet (9-15 m) in cultivation and occasionally 80 feet (24 m) in the wild. Young trees are conical, broadening with age into an irregular, rounded crown, while exposed treeline specimens may grow low and contorted. The common name refers to the young branches and twigs, which are so pliable they can be bent into a loop without snapping. Needles are borne five to a bundle, 1.5-3 inches (4-8 cm) long, dark blue-green, and crowded toward the branch ends. The cones are 3-6 inches (8-15 cm) long with thick scales and hold large, wingless seeds that are carried and cached by Clark's nutcracker. Bark is silvery-grey and smooth on young trunks, darkening and furrowing into blocky plates with age. P. flexilis grows on dry, rocky ridges and slopes, often in poor soil and high wind. It is very slow to develop and is susceptible to white pine blister rust, which limits its lifespan in some regions.
Native Range
Native to the mountains of western North America, from Alberta and British Columbia south through the Rocky Mountains to New Mexico and west across the Great Basin to the Sierra Nevada of California. It grows at moderate to high elevations, often near treeline, on dry, rocky, exposed sites.Suggested Uses
Grown as a specimen or screen in cold-climate and mountain gardens, in rock gardens and large containers while young, and in restoration of high-elevation sites. Its wind and cold tolerance suits exposed slopes and northern landscapes. Dwarf and blue-needled selections are used in smaller gardens and conifer collections.How to Identify
Appearance
Size & Dimensions
Height30' - 50'
Width/Spread15' - 35'
Colors
Foliage Colors
Fall Foliage Colors
Bloom Information
As a conifer, P. flexilis produces cones rather than flowers. Reddish pollen cones and small purple seed cones appear in late spring to early summer, around May to July. Seed cones take two seasons to ripen, maturing to woody brown structures the following autumn.
Detailed Descriptions
Flower Description
cones reddish to purpleFoliage Description
dark blue-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
Grow in full sun on well-drained soil; it tolerates poor, rocky, and alkaline ground and exposed, windy sites. Water young trees through dry spells until established, then rely mainly on rainfall, as the species withstands drought and cold once rooted. It grows very slowly and declines in wet, poorly drained soil, which encourages root disease. Hardy into zone 2, it suits cold mountain and northern climates. Little or no feeding is needed in lean soils. Where white pine blister rust is present, choosing rust-resistant stock reduces losses.Pruning
Pruning is rarely required, and limber pine keeps a natural form with little intervention. Dead, damaged, or diseased branches are removed in late winter, and any pruning of live wood is kept light to preserve the crown shape. Removing branches infected by blister rust can slow the disease spread.Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons