Fig. 5: Well-shaped tree and foliage of Scotch pine.
Needles of the pines are borne in bundles of two or more along the twigs and are relatively long in comparison to those of spruces, true firs and Douglas-fir. Nutrient and water requirements are generally somewhat less exacting than those of most spruces, true firs and Douglas-fir. Because of this, pines are usually adapted to a wider variety of sites. Needle retention on cut trees is excellent.
Scotch Pine (Pinus sylvestris): Scotch pine, a two- needled pine native to Europe and Asia (Fig. 4) is the most widely planted and most extensively used Christmas tree species in Ohio (Fig. 5). There is considerable genetic variability in the species, and foliage color, needle length, stem straightness and growth rate vary greatly depending on the area from which seed was collected. Seedlings raised from seed sources originating in southern France and Spain appear to be best for planting in Ohio, although foliage of those from Spain may be injured by winter drying ("winter burn") during very cold winters. Trees from other southern and western portions of the range, particularly from Scotland, Greece and Turkey also show promise. Trees from these areas have relatively short needles, adequate growth rate and green or blue-green winter foliage.
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| Fig. 4: Native range (shaded area) of Scotch pine. Numbers show locations of areas from which seed was collected for use in research studies. | Fig. 5: Well-shaped tree and foliage of Scotch pine. |
Scotch pine prefers moist, well drained soils but grows reasonably well on sites ranging from relatively dry to moderately wet. Although Scotch pine requires considerable shaping to produce high quality trees, it responds well to shearing. Depending on site characteristics and cultural practices, 6- to 7-foot Christmas trees can be produced in six to nine years.
Particularly troublesome pests of Scotch pine include sawflies, European pine shoot moth, white pine weevil, spotted pine needle aphid, pales weevil, northern pine weevil, Nantucket pine tip moth, eriophyid mites, Diplodia tip blight and needle casts, particularly those caused by the fungi Lophodermium pinastri and Naemacyclus minor. (More detailed information on insect, disease and animal pests of Christmas trees and their control is available from the Ohio Cooperative Extension Service).
White Pine (Pinus strobus): Eastern white pine is a five- needled pine native to southern Canada, the Lake States and the eastern United States (including scattered locations in Ohio) southward through the Appalachian Mountains and Plateau to northern Georgia (Fig. 6). Seedlings raised from seed sources from the southern portion of the species range tend to have longer, bluer-green needles and better second-year needle retention. They should be preferred for Christmas trees when available. Branches are slender and flexible, and trees usually require fairly heavy shearing to produce high quality trees. More growers in Ohio are planting eastern white pine due to increased demand for the species.
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| Fig. 6: Well-shaped tree and foliage of white pine. |
White pine prefers moist, well-drained soils but will grow on sites ranging from relatively dry to wet. It appears to be somewhat more tolerant of wet soils than Scotch pine, although trees on wet sites may suffer from white pine root decline. Fertility requirements of the species are somewhat higher than those of Scotch pine but are not as high as those of most spruces, true firs or Douglas-fir. White pine does well at all latitudes in Ohio, and 6- to 7-foot Christmas trees can be produced in six to nine years.
Important pests of eastern white pine include white pine weevil, various sawflies, bark and needle aphids, pine tube moth, white pine blister rust and white pine root decline, particularly on wet sites. White pine is also very susceptible to injury by atmospheric impurities, particularly sulfur dioxide, ozone and gaseous fluorides. Damage from air pollution may range from extreme stunting of growth and death of all or parts of the needles ("chlorotic dwarf") to mild yellowing of foliage. In areas where sulfur dioxide and ozone concentrations are high, 25 percent or more of trees in plantations may have visual symptoms. If white pine foliage gets wet on the sales lot, needles tend to clump together, decreasing the feathery natural beauty of trees. However, needles regain their natural appearance after drying.
Other Pines: In the past, two other pines, Austrian or black pine (Pinus nigra) and red pine (Pinus resinosa), were grown extensively for Christmas trees in Ohio. However, these species are difficult to shape into high quality Christmas trees, and growers now generally prefer Scotch and white pine. Austrian pine is still produced in limited quantities for live ornamental sales. Moisture requirements of Austrian pine are similar to those of Scotch pine. However, its nutrient requirements are considerably higher. It is a species that grows well on soils having a high pH. Austrian pine is also resistant to salt and air pollution injury.
Southwestern white or border pine (Pinus strobiformis) is another pine being planted in limited quantities by Christmas tree growers in Ohio. It appears promising for expanded planting. It is a five-needled pine, similar to eastern white pine, but has shorter needles that are usually retained for two or more years. Limbs are stiffer than those of eastern white pine. Site requirements and cultural practices needed to produce quality trees have not been well established in the state, and until more is learned about the species, growers should be cautious when planting it.