Limber pine's gardening advantages begin with its growth form, because unlike our familiar evergreens it produces a stout, short trunk rather than a tall, gradually tapering bole. The trees grow 9 to15 m (30 to 50 ft.) tall and bear widely outstretched branches even near the top. As a result the form resembles a very large shrub more than a tree. The branches occur all along the trunk to the bottom where, in natural settings, they may grow snake-like along or near the ground. Branches are often very crooked and so flexible and tough that some can be tied into a knot. This flexibility is the source of both the common name "limber" and the species name "flexilis." As in many species in the white pine group, 3- to 8-cm-long (1.2- to 2-in.) flexible needles occur in clusters of five along the branches. Needle bundles are typically crowded toward the ends of the branches but also occur into the middle, another visually pleasing feature. They are an attractive bluish green and delightfully scented. Pollen is produced in small yellowish male cones, whereas the female cones are long (7 to 22 cm/21⁄2 to 81⁄2 in.) and relatively firm. Mercifully the scales, though thick, are not equipped with the sharp spines of other pine species. Large thick seeds are reddish brown and wingless. Limber pine is not easy to find in the wilds of British Columbia because it grows only in the extreme southeast corner, high up in the Rocky Mountains. The range includes adjacent Alberta and extends southward through the Rockies into northern Mexico and westward into California and eastern Oregon. Throughout most of its range it is a true mountain tree; it occurs in B.C. on slopes and ridge tops from about 1,500 to 2,000 m (4,920 to 6,560 ft.) above sea level and well above 3,000 m (9,840 ft.) farther south. Its favoured sites are rocky and dry. Under such conditions it forms the twisted dense specimens so often photographed as an icon of our mountain scenery. Despite its harsh natural habitat, limber pine is very well suited to coastal gardens. At the Royal BC Museum native plant garden in downtown Victoria, a limber pine has grown trouble- and disease-free for almost 40 years. It forms a dense, rich-green tree about 7 to 8 m (23 to 26 ft.) tall producing a few attractive cones each year. Limber pines are best raised from seed, if you can get it, or purchased from a specialist nursery. Several dwarf and oddly growing forms are available in the conifer trade. It is also used for bonsai. In your landscape, choose a well-drained sunny site; rocky conditions are particularly suitable. Limber pine is noted as being especially drought tolerant, and it's worth experimenting with in interior B.C. gardens because it has exceptional frost hardiness. Pruning will help shape the tree into whatever form, fantastic or otherwise, you might want, but in general the relatively slow growth means it requires little attention. Limber pine's greatest horticultural advantage, aside from its tough character, is its slow and constrained growth. Unlike so many of our other natives it spreads gradually outward and does not reach for the sky to interfere with sunlight and power lines or rain debris upon your home. Incidentally, the most ancient known limber pine is about 1,700 years old. The relatively large and nutritious seeds were widely collected and eaten by First Nations people and later European pioneers. The seeds are valuable for birds, too, and are a favourite of Clark's nutcrackers. Search out the unusual - try limber pine for your urban or suburban lot. Hardy, drought resistant, slow-growing and attractive, this native evergreen may well be a better subject than some of the standard available conifers. The following plant is hardy to the zone number indicated: Pinus flexilis (limber pine) - zone 3 An expert on native plants, Richard Hebda is curator of Botany and Earth History at the Royal British Columbia Museum in Victoria.
Credit: Richard Hebda