Since last week I introduced you to a relatively recent introduction to the North American gardening landscape (the goumi, Elaeagnus multiflora, which you can read all about right here) that can only be cultivated in the warmer parts of Canada (namely southern Ontario, Quebec and the Maritimes), so I thought that It would only be fair to the rest of the country to bring your attention his week to one of many nut producing pines, the stone pine (Pinus cembra) which can be successfully grown throughout most of Canada.
Pinus cembra, known as the Swiss pine, Allora pine or simply stone pine, is a coniferous tree indigenous to high elevations in the mountains of central Europe. These trees grow rather slowly in their native range where the growing season is often very short but can live to be several hundreds of years old, capable of reaching 60 feet in height. They are quite cold hardy, tolerating temperatures down to at least -30°C and therefore show great potential for being grown in similarly cold regions of northern North America.
The needles grow in bundled of 5, bound together at their base by a thin, papery sheath. The cones are nearly as wide as they are long and are produced individually or in clusters near the branch tips. They take approximately 30 months to mature and are comprised of wide, blunt-tipped overlapping scales. Young cones are an attractive purple-grey color and mature to a drab brown before they are conveniently discarded by the tree, often before the scales open, and can be collected from the ground underneath the tree.
The thin shelled seeds are delicious and rich in oils with a nutty, slightly resinous flavor. They are found in pairs underneath each of the scales and are often easily dislodged. They can be eastern raw or roasted and then shelled and added to a variety of different foods. Pine nuts (although not actually truly ‘nuts’ in the botanical sense) from Pinus cembra are a common and highly revered food source in regions where the trees are common and, as I’m sure you’re aware, often fetch steep prices when they are collected or cultivated and exported abroad.
There are few varieties of Pinus cembra that are known for their horticultural value including ‘Algonquin Pillar’ and ‘Stricta’ which have more or less erect growth without much outward, horizontal growth with perpendicular boughs which curve upright and remain tight against the frame of the tree. Highly tolerant of exposure and winter winds, these trees make effective shelter belts and in addition to this service they also produce an edible seed, medicinally valuable foliage and resin as well as lumber which can be used for a variety of different purposes.
Pinus cembra is certainly not the only species of pine in the world that produces large enough seeds that either domesticating the plants or foraging for the seeds in the wild has been considered worth while or an economically viable enterprise. The Korean pine (P. koraiensis) is perhaps the most commercially viable species as it produces slightly larger seeds inside of correspondingly larger cones than P. cembra and is similarly hardy. The Italian stone pine (P. pinea) is another species that is commonly utilized in parts of southern Europe but is not as cold tolerant therefore unlikely to succeed in Canada.
In North America, the pinyon pine (P. edulis and P. monophylla) as well as the Mexican pinyon pine (P. cembroides), which grow throughout the American southwest and northern Mexico are utilized locally for their edible seeds. With the possible exception of P. cembroides (see bottom page of 5) these species likely won’t survive in any but the mildest regions in Canada. However, there are a great deal of them that can tolerate the harshest Canadian climates and frankly (in my humble opinion) nut pines are not being utilized enough in this country for their beauty, functionality, and delicious seeds.
Quite unlike the above species, which are all definitely trees, the Siberian dwarf pine (P. pumila) also produces small, rounded cones which contain large, thin-shelled edible seeds and is a species worth knowing. For starters, P. pumila is quite possibly one of the cold hardiest trees in the world, capable of withstanding absolutely obscene -50°C winters in it’s native range of north-eastern Siberia and the high mountains of Japan, Korea and Mongolia. As the name implies, this pine prefers to grow only a few meters tall at the most with sprawling, twisting limbs that grow horizontally across the ground.
The short stature of P. pumila is undoubtedly an adaptation to it’s frigid, wind-swept environment of steep mountainsides, rocky escarpments and boulder outcrops. This quality makes it a desirable specimen for planting in any situation in which a full-sized tree would be either aesthetically or functionally inappropriate or if the conditions of the site would not allow for a larger tree to prosper. Exposed sites with thin, poor or acidic soils would be suitable for this species as well as along the edges of forests, buildings, sheds or gardens where shade would be prohibitive.
Note: During my research to produce this article, I came across dozens of species of pine trees found all over the world that produce an edible seed. There are far too many of them for me to mention here, but I encourage you to explore the diversity. To help get you started, I encourage you to check out P. bungeana, the lacebark pine, a species native to China which is quite well known as an ornamental due to it’s smooth, patchy white and green bark.
Additionally interesting is the incidence of ‘pine mouth syndrome’ , a type of taste disturbance which occurs in some individuals after consuming raw pine nuts, most often from the species P. armandii. Symptoms include a bitter, metallic taste in the mouth that can last for several days after consumption but has no long lasting negative effects. The Food and Drug Administration looked into this matter and concluded that it separate from a food allergy but is indeed an observable phenomenon affecting a small portion of the population.