Wednesday, November 29, 2006

Christmas Trees in the Midwest

The proper choice of a species of plant, including Christmas Trees is important. Unless an appropriate choice is made, a lot of time and money can be lost if you want to plant trees on your property.

A number of considerations should be reviewed: 1. your preferences, 2. the characteristics of different species, 3. the characteristics of lands to be planted, 4. trees, and their growing requirements, 5. the presence of any damaging agents, and 5. nearness to sales outlets.

Your tree preferences can vary considerably from one area to another, influenced by the type of tree you have used previously perhaps. Plantation-grown trees became generally available in Ohio, native species such as white pine were often used for Christmas trees in central, and northern parts of the state, and the eastern red cedar or the Virginia pine were common in warmer areas.

Large numbers of balsam fir, white spruce, and black spruce imported from Canada have been a hit in Ohio. As large quantities of plantation-grown trees became more available, the more traditional preferences went by the wayside. More emphasis has been placed on characteristics of different imported and native tree species grown on from plantations. Leaf color, needle length, needle retention, stem shape, and density are among the vital consideration influencing a final choice for your Christmas trees.

Choosing a tree that will survive and thrive in a particular area is a vitally important issue and often very difficult to decide. A combination of soil characteristics, topography, climate factors, and biotic agencies dominant in an area constitute the specific "site factors" of that area of property. The combination of these factors, along with the ecological requirements of each particular species, must be carefully considered in order to ensure successful establishment, survival, and growth of Christmas Trees.

In the Midwest, an evaluation of site factors in relation to ecological species requirements can be difficult because of the variations in soil, topography, and climate conditions that are associated with changes in latitude, in addition to large variations in soil conditions in different parts of a state.

Christmas Tree growers should also seek professional forestry advice from service and consulting foresters, the Soil Conservation Service, or local county agricultural extension agents. Tremendous help is also available form visiting Christmas Tree farms and talking with their growers about their experiences with different species of Christmas Trees on different sites.

The presence of damaging agents should be particularly considered when choosing a species to plant in a specific area of property. These considerations should include the effects of local and seasonal insects and diseases, but also factors that include winter hardiness, susceptibility to spring frost damage, and any likely ice and snow breakage, as well as sensitivity to air pollutants. All these things can destroy your Christmas Trees. The following are some recommendations for pines and spruces that will grow well in Ohio and other parts of the Midwest USA. Check your local nursery or library for additional information.

The needles of pines come in bundles of two or more along the tree twigs and are long in comparison to those of spruces, true firs, and Douglas firs. Nutrient and water requirements are a bit less exacting than for most of those trees as well. Because of this, pines are usually adapted to a wider variety of sites, and needle retention on these cut trees is excellent, with very little needle drop.

Scotch Pine
Scotch pine is a two- needled pine native to Europe and Asia, widely planted and most extensively used as a Christmas Tree in Ohio and the Midwest. There is considerable genetic variability in the species foliage color, needle length, stem straightness and growth rate. Seedlings raised from seed from southern France and Spain are best for Ohio, although foliage of those from Spain may be injured by winter drying (winter burn). Trees from other southern and western portions of Europe, such as Scotland, Greece, and Turkey also do well. They have short needles, an adequate growth rate, and attractive green or blue-green winter foliage.

Scotch pine prefers moist, well-drained soil but grows on sites ranging from dry to moderately wet. Scotch pine requires considerable shaping to produce high quality trees, but shearing works well. Depending on site characteristics and cultural practices, 6- to 7-foot Christmas Trees can be produced in just six to nine years. Troublesome pests include sawflies, European pine shoot moth, white pine weevil, spotted pine needle aphid, pales weevil, northern pine weevil, Nantucket pine tip moth, mites, Diplodia tip blight and needle casts, among others.

White Pine
Eastern white pine is a five- needled pine native to southern Canada, the Great Lake States, and the eastern United States, including Ohio, south to the Appalachian Mountains to northern Georgia. Seedlings raised from seed from southern portion of the species range have longer, bluer-green needles and better second-year needle retention. Their branches are thin and flexible, and trees usually require heavy shearing to produce high quality trees.

White pine prefers moist, well-drained soil but will grow in dry to wet land. It is more tolerant of wet soils than Scotch pine, but trees on wet land may suffer white pine root decline. Fertility requirements are slightly higher than those of Scotch pine, but not as high as spruces, true firs, or Douglas firs. 6- to 7-foot Christmas Trees can be produced in six to nine years.

Pests of the eastern white pine include white pine weevil, sawflies, bark aphids, needle aphids, pine tube moth, white pine blister rust, and white pine root decline. White pine is also susceptible to injury by air pollution, including sulfur dioxide, ozone, and fluorides. Damage from air pollution may range from extreme stunting of growth to death of all or parts of the needles. It may result in mild yellowing of foliage. If white pine foliage gets wet, its needles clump together, decreasing the feathery beauty of the tree. Needles will regain their natural appearance when drying.

Other Pines
Austrian or black pine and red pine were grown extensively for Christmas Trees in the past. These species are difficult to shape into Christmas trees and growers prefer Scotch and white pines. Austrian pine is still produced for live ornamental sales, with moisture requirements similar to those of Scotch pine. Its nutrient requirements are much higher and it grows well in soils with a high pH (acidic). Austrian pine is also resistant to salt and air pollution.

Southwestern white or border pine is planted in limited quantities by Christmas Tree growers in the Midwest. 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 and the site requirements to produce quality trees are not well established.

Spruce needles grow singly along twigs and are relatively short and sharp-pointed. Needle retention on cut trees varies, but is not as good as on pines. Although most species of spruce prefer moist, well-drained soils with good fertility, they grow on sandy soils if there is a good water table through the growing season. Growth of most spruces is not as good on poorly drained clay soils.

Spruces undergo a slow period of establishment growth after planting, after which growth is usually rapid. Although the basic form of most trees is good, some shearing is needed. Most spruces are subject to spring frost injury if they leaf out early and low-lying sites (frost pockets) should be avoided.

Colorado Spruce
Colorado or blue spruce is a native of the western United States but is planted as a Christmas Tree in Ohio. Needles are longer than those of Norway and white spruces and are very sharp-pointed. Although foliage on some is a bright bluish color, most seedlings are green to blue-green. This characteristic is somewhat related to seed source and trees produced from seed originating in the southern Rocky Mountains of Colorado, Arizona and New Mexico are preferred for Christmas trees.

Needle retention on cut trees is better than for white and Norway spruces and almost as good as that of pines. Growth is usually slower than that of Norway and white spruces. Moreover, 8 to 12 years are required to produce 6- to 7-foot trees. Sawflies, gall aphids, spider mites, white pine weevil, Cytospora canker, and Rhizosphaera needlecast are the major pests affecting this tree.

Norway Spruce
Norway spruce is a native of Europe and one of the most widely planted Christmas Trees in Ohio. Temperatures in most of the state are suitable, and it is generally easier to establish than any of the other spruces. A rotation of 7 to 11 years is needed to produce 6- to 7-foot trees on good sites. However, needle retention on cut Norway spruce is very poor and sales and planting of it have declined. To minimize needle drop, cutting should be delayed as long as possible. Pests of the Norway spruce include gall aphids, white pine weevil, spider mites, Cytospora canker, and Rhizosphaera needlecast.

White Spruce
White spruce is native to the northern US and Canada. The needles are whitish or bluish and while needle retention is not as good as among pines, it is generally better than for Norway spruce. However, like Norway spruce, trees cutting should be delayed as long as possible. Eight to 11 years are required to produce 6 to 7-foot trees on relatively good sites. Gall aphids, spider mites, and Rhizosphaera needlecast are major pests for white spruce.

Other Spruces
There are a number of other spruces used for Christmas Trees. Red spruce and black spruce were used in the past, but their site requirements are more demanding than those of Norway, white and blue spruce, and red and black spruce.

Several European and Asiatic spruces are promising, but have not been fully tested and cannot be recommended. One species for which information is available is the Serbian spruce, a native of southern Europe with soft needles that are dark green above and bluish below. Its branches are limber, often giving trees a droopy appearance. Site requirements are similar to those of the Norway spruce. Growth, however, begins later in spring than the Norway spruce and Serbian spruce is not as likely to be damaged by late spring frost. However, needle retention on cut trees is poor.

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