Contact: Diane Relf, Extension Specialist, Environmental Horticulture
Posted April 1997
Pines constitute a major group of ornamental narrowleaf evergreens with most types being large tree forms. There are some slower growing and dwarf cultivars; however, only a limited number are produced in quantity for landscape use. Pines are also of prime importance for timber, watershed, and Christmas tree use and as sources of pitch, resin, and turpentine as well as edible seeds.
Characteristics:
The resinous evergreen trees, have whorled branches and furrowed bark. The leaves are needle-like, bluish to dark green color borne on an undeveloped branchlet in clusters of 2 to 5. Flowers are monoecious (separate male and female flowers on the same plant), the male flowers are yellow, or orange, and the catkin-like female flowers are greenish or purplish. The familiar cones develop from the female flowers.
Growth Characteristics:
The majority of the Pines are large symmetrical trees of pyramidal or round topped form usually becoming open and picturesque with age. There are some shrubby forms such as Pinus mugo var. mugo; however, most are rare in cultivation. There are two narrow upright types which are available in limited quantity: (1) Pinus sylvestris 'Fastigiata' and (2) Pinus Strobus 'Fastigiata'.
Culture:
In general, Pines are tolerant of adverse soils and exposure, as well as city conditions. The degree of tolerance varies within the genus. However the two needle forms seem to be the most tolerant, and the five needle forms the least tolerant. Species such as P. sylvestris, P. nigra, and P. cembra can be planted in any soil type; whereas, some such as P. mugo var. mugo will perform best in a sandy soil.
With the exception of seedlings, pines should be transplanted with a ball of soil. Large natural growing specimens may be difficult to move due to a tendency to form deep tap roots. Either fall or spring transplanting is satisfactory. All types can be pruned if necessary; however, extensive pruning on established plants in the landscape is usually not required. Pruning of younger specimens helps to develop a compact plant. Remove half the growth of each young candle in the spring to increase side shoots and compactness.
The most serious disease is Tip Blight with is usually confined to Austrian Pine (P. nigra). If present, the branch should be pruned and the new growth sprayed 3 times with a copper fungicide. A number of insects including scales, aphids, weevils, beetles and shoot moths may become troublesome at times. These can all be controlled with a timely application of the proper insecticide.
Landscape Use:
The tree species and cultivars of pine are used extensively in large scale landscape plantings such as parks, golf courses, estates, cemeteries, industrial grounds, shopping centers, and public buildings. More interesting landscape effects result when using a few or individual specimen plants, rather than mass planting, due to the interesting outlines and branching habits. Variations in color from blue to dark green and in texture from fine to coarse creates interest in any landscape.
Large dense specimens of groups should be used carefully, if at all, on small properties because of the massive and overpowering effects, unwanted shade in winter, and interference with air movement. For small properties, foundation plantings, or shrub borders, the best pines to use are the shrubby forms or the narrow upright types. Pine trees planted as a windbreak are also useful in the large home landscape (one-half acre or more). The interesting shapes and growth characteristics of the larger pines serve as ideal accent or focal points when placed alone in the landscape as long as you have allowed enough room above and around the plant to permit healthy growth.
(Excerpted from "Landscape Facts," Elton M. Smith, Extension Specialist, CES, Ohio State University.)
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