Swiss Stone Pine
A native of the Alps and Carpathian Mountains of central Europe, Swiss Stone Pine was introduced to the US as a tough and cold hardy addition to our suburban landscapes. It can attain heights of 80 to 120 feet high by 25-50 feet wide in its native environs, but usually attains a height of 40-60 feet and a width of 20-30 feet in the US. There are also several dwarf and miniature varieties that mature at lesser sizes, including some used for bonsai. Swiss Stone Pine is a slow growing species that can live 500-1000 years in its native climate and easily to 100 in the US. It develops and maintains a dense conical shape when young right through old age.
The needles are in bundles called fascicles in groups of five and are 2.5 to 4 inches long. They are blue green in color and soft to the touch. Young candles emerge light green and provide an interesting contrast in spring. The new needles usually persist for three years before dropping.
Fruits or cones are rounded 1.5-3” in size and appear alone or in clusters turning from green to brown and maturing in three seasons. The cones are often sliced and used to flavor local schnapps in Europe. The bark is a dark grayish brown with raised scaly plates as it matures, and can be quite attractive, especially when accented by winter snows.
Swiss Stone Pine is considered one of the hardiest of the pines able to be grown in sand or clay and tolerate urban, suburban and even drought conditions. It is a tough tree resistant to most insect and disease problems, including white pine blister rust.
Swiss Stone Pine can be hard to transplant, but once established, it is a cold hardy and low maintenance tree for the landscape. Providing a moist well drained soil with a sunny location, and good cultural practices of routine pruning to remove dead or diseased tissue, watering the root zone and not the foliage, and leaving fallen needles as a natural mulch is the best way to ensure the best performance from this worthy and attractive conifer.