ACS Distance Education UK
Pines are evergreen plants in the genus Pinus.
Some are eaten; but many are not.
They vary greatly in size, cones are hard, woody and have thick scales. Branches grow out of main trunk in whorls (making pines easy to climb). They are readily distinguishable from all other conifers because most of their leaves are in groups, usually 2 5 on short spurs the number of needles emerging from a spur (i.e. per bundle) can be a good indication of which species you are looking at.
Edible nuts are produced by many different types of pines, but some are more palatable than other. Several species of Pinus in particular are commonly eaten in different parts of the world. Pinus pinea nuts, for example, can be purchased in retail stores in Australia, Europe and other parts of the world. Although there are at least 15 species of pine nuts which are harvested and eaten, in most instances they are only used as food in a local area where they occur. The Hopi and Navajo indians of North America for instance, eat nuts from Pinus cembrioides and some related species, either as whole kernels or ground into a flour and baked. Pinus gerardiana is another species, from which nuts are a relished food in parts of central Asia where it occurs. Nuts from this pine (called Chilgoza nuts) are exported from parts of the Himalayas and Afghanistan, into India.
Many pine species can be slow to start bearing seeds (commonly well over a decade; and sometimes many decades); but they can be long lived; sometimes well over 1,000 years. These are obviously trees to plant for future generations.
Most are generally very hardy once established.
Pruning should be minimal if you want a well formed tree however any pruning that is done should preferably be done in spring.
Though generally resistant to serious problems, a wide range of pests and diseases have been recorded on pines, including: damping off and root rot (particularly on seedlings, dieback (more serious on younger plants), rusts, blights, wood rots; aphids, caterpillars, sawfly, web worms, scale, leaf miners borers, and weevils.
Pines can also suffer from soil problems. A deficiency or excess of water can cause needles to drop. Root damage or nutrient deficiencies may cause stunted growth. Air pollution and salt have also been known to severely effect (sometimes kill) pines.
Seed is common, cuttings or grafting occasionally. Cones are slow to develop, maturing at the end of summer or into autumn of the second season following their initiation. In most species, cones open to drop seed soon after ripening, so collect cones at this stage and air dry to release seed.
Most species can be grafted onto seedlings in winter, most commonly using a side graft. The rootstock selected will be dependent upon the cultivar being grafted (not all pines graft well onto all species).
Seed will maintain viability if stored dry and at low temperatures. Germination can be variable between species. Many will germinate without stratification, but for some, stratification is essential. Stratify by soaking in water for 24hrs, then placing in a bag with moist peat or perlite in the bottom of a refrigerator (around 1-2oC) for a period (some species require 3 months stratification, others only 2-4 weeks).
Nuts are small, but produced in large quantities. Trees that are over 2,000 years old in Russia have produced large crops Collect nuts while slightly immature, then dry and store. Mature nuts are not as tasty for eating.
A traditional food for the Native Americans.
Very large cones and very large edible seeds.
Pinus edulis (Colorado Pinyan)
Grows 3 to 15 m tall it produces small cones to about 5 cm long that contain edible nuts.
Pinus lambertiana (Sugar Pine)
This occurs from western USA and northern Mexico, 3 sided needles have white lines on all sides, in bundles of 5; 5 to 10cm long, massive woody cones furrowed bark is reddish brown.
Pinus pinea (Stone Pine)
This is the species most often sold commercially as "pine nuts". It is easily recognised by its very wide spreading and rounded or flat topped crown. The bark is orange red and deeply fissured into large vertical plates. Cultivated commercially in Portugal the nuts are sweet tasting, can be eaten raw, steamed or roasted. Young stems are pale and hairless. The dark green leaves are 10 to 15 cms long, stout, often twisted and borne in pairs. The large broad ovoid cones are 8 to 15 cms long. The trees have a maximum height of about 20 m. Tolerant of wind and some coastal conditions.
20 hour short course