Saskatchewan Perennial Society
Pines are found world-wide, mostly in the Northern Hemisphere. Pinus is the classical Latin name for this genus. Many pines, both native and introduced, do well on the prairies. These range from dwarf “buns” such as ‘Slowmound’ mugo pine to towering trees like white pine and lodgepole pine.
In spite of their size differences, they share many characteristics. Most prefer lighter sandy soils. All grow best in full sun. Generally tougher than spruce or fir, their deep tap root enables them to “tap” water from the subsoil during drought.
Pines have needles in bundles of two, three or five, depending on the species. Needles that are in bundles of two, such as those of Scots, mugo and jack pine, are semi-circular in cross-section and tend to be stiff. Needles in bundles of three or five, such as those of white pine and limber pine, are triangular in cross-section and softer and more slender.
Depending on the species, the needles remain on a tree for 2 to 5 years (or longer), turn yellow, later brown, and then drop. Because needles on the “inside” of the tree, closest to the trunk, are the oldest, they are the ones that brown and fall first. When pines are stressed by heat or drought, many needles may fall at once. This is your cue to water deeply and then mulch.
As pines age, they often (but not always) lose their lower branches, exposing attractive, furrowed bark. Deer love the younger needles of pines (especially those with softer needles such as Swiss stone pine) and may denude branches within browsing level.
Male and female “flowers”, in the form of cones, are separate but formed on the same tree. Small red male pollen cones, quite visible in early spring, are formed in clusters at the end of branches at the base of the tree on new shoots. They open in the spring to release wind-born pollen and then disintegrate. The female cones are formed at the tips of new shoots.
We’ll begin with those closest to home: Jack pine and lodgepole pine.
Jack pine (Pinus banksiana) is the most widely distributed pine across Canada with a natural range from the Arctic Circle to the Great Lakes, including the boreal forests of the prairies. The species name honors Sir Joseph Banks (1773-1820), the British horticulturist of Kew Gardens fame who initiated many of the plant hunting expeditions of his era.
Jack pines can naturalize on poor soils. They are extremely hardy with the ability to survive adversity but are not generally recommended as an urban ornamental conifer. For those who have lived in the Boreal forest they are a reminder of home. For others, perhaps a reminder of a Charlie Brown Christmas tree.
They have an open irregular form (20 x 7 m / 65 x 25 ft.), dark brown, furrowed, irregular bark, and short dull green needles in bundles of two. The dark purple curved cones, often in pairs, point toward the tips of the branch, and persist on the tree until they open and release seeds by the heat of fire. They are the first trees to colonize a burned area. Their natural habitat is dry sandy or gravelly soil in full sun to which their deep and extensive root system is well adapted. They can live for 150 years.
Lodgepole pines (Pinus contorta var. latifolia) are native to the Cypress Hills of Alberta and Saskatchewan as well as the Rocky Mountains. The species name, contorta, means twisted. It may refer to the gnarled branches or the twisted needles. The long straight young trunks were once used in the construction of teepees and lodges, hence the common name. Indigenous Peoples used the resin to waterproof canoes, baskets and moccasins.
Over 18m (60 ft) tall, lodgepole pines can live to be 200 years old. The dark green to yellow green needles are in bundles of two, twisted and sharply pointed. The cones persist on the tree for 10 to 20 years. It is drought-tolerant and adaptable to a wide range of soils. It is useful in a large landscape, for screening, as a specimen tree and in shelterbelts.
Sara Williams is the author and coauthor of many books including Creating the Prairie Xeriscape, Gardening Naturally with Hugh Skinner and, with Bob Bors, the recently published Growing Fruit in Northern Gardens. She continues to give workshops on a wide range of gardening topics throughout the prairies.
This column is provided courtesy of the Saskatchewan Perennial Society (SPS; firstname.lastname@example.org ). Check our website (www.saskperennial.ca) or Facebook page (www.facebook.com/saskperennial) for a list of upcoming gardening events.