Natural trees

The best species for use are species of fir (Abies), which have the major benefit of not shedding the needles when they dry out, as well as good foliage colour and scent; but species in other genera are also used. Commonly used species in northern Europe are:

* Silver Fir Abies alba (the original species)
* Nordmann Fir Abies nordmanniana (as in the photo)
* Noble Fir Abies procera
* Norway Spruce Picea abies (generally the cheapest)
* Serbian Spruce Picea omorika
* Scots Pine Pinus sylvestris

and in North America and Central America:

* Balsam Fir Abies balsamea
* Fraser Fir Abies fraseri
* Grand Fir Abies grandis
* Guatemalan Fir Abies guatemalensis
* Noble Fir Abies procera
* Red Fir Abies magnifica
* Douglas-fir Pseudotsuga menziesii
* Scots Pine Pinus sylvestris
* Stone Pine Pinus pinea (as small table-top trees)

Several other species are used to a lesser extent. Less-traditional conifers are sometimes used, such as Giant Sequoia, Leyland Cypress and Eastern Juniper.

Various types of spruce tree are also used for Christmas trees, and are thought by some to be the most beautiful of all species used for this purpose. But spruce trees (unlike firs) begin to lose their needles rapidly upon being cut, and many spruces, such as the Blue Spruce have very sharp needles, making decorating uncomfortable.

Virginia Pine is still available on some tree farms in the southeastern United States, however its winter colour is faded. The long-needled Eastern White Pine is also used there, though it is an unpopular Christmas tree in most parts of the country, owing also to its faded winter coloration and limp branches, making decorating difficult with all but the lightest ornaments.

Norfolk Island pine is sometimes used, particularly in Oceania, and in Australia some species of the genera Casuarina and Allocasuarina are also occasionally used as Christmas trees. Hemlock species are generally considered unsuitable as Christmas trees due to their poor needle retention and inability to support the weight of lights and ornaments.

Some trees are sold live with roots and soil, often from a nursery, to be planted later outdoors and enjoyed (and often decorated) for years or decades. However, the combination of root loss on digging, and the indoor environment of high temperature and low humidity is very detrimental to the tree’s health, and the survival rate of these trees is low.

These trees must be kept inside only for a few days, as the warmth will bring them out of dormancy, leaving them little protection when put back outside into the midwinter cold in most areas. Others are produced in a container and sometimes as topiary for a porch or patio.

European tradition prefers the open aspect of naturally-grown, unsheared trees, while in North America (outside western areas where trees are often wild-harvested on public lands) there is a preference for close-sheared trees with denser foliage, but less space to hang decorations.

The shearing also damages the highly attractive natural symmetry of unsheared trees. In the past, Christmas trees were often harvested from wild forests, but now almost all are commercially grown on tree farms.

Almost all Christmas trees in the United States are grown on Christmas tree farms where they are cut after about ten years of growth and new trees planted.

According to the United States Department of Agriculture (USDA) agriculture census for 2002 (the census is done every five years) there were 21,904 farms were producing conifers for the cut Christmas Tree market in America, Template:Convert/hectare were planted in Christmas Trees, and 13,849 farms harvested cut trees.

The top 5% of the farms (40 ha / 100 acres or more) sold 61% of the trees. The top 26% of the farms (8 ha / 20 acres or more) sold 84 percent of the trees. Farms less than 0.8 ha (two acres) comprised 21% of the farms, and sold an average of 115 trees per farm

In the UK, The British Christmas Tree Growers Association represents the interests of all those who grow Christmas trees in Great Britain and Northern Ireland.

The lifecycle of a Christmas tree from the seed to a 2-metre (7 ft) tree takes, depending on species and treatment in cultivation, between 8 and 12 years. First, the seed is extracted from cones harvested from older trees.

These seeds are then usually grown in nurseries and then sold to Christmas tree farms at an age of 3-4 years. The remaining development of the tree greatly depends on the climate, soil quality, as well as the cultivation and tendance by the Christmas tree farmer.

Artificial trees

Artificial trees have become increasingly popular, as they are considered more convenient and (if used for several years) less expensive than real trees, as well as less wasteful than cutting down real trees.

Trees come in a number of colours and “species”, and some come pre-decorated with lights. At the end of the Christmas season artificial trees can be disassembled and stored compactly.

Artificial trees are sometimes even a necessity in some rented homes (especially apartment flats), due to the potential fire danger from a dried-out real tree, leading to their prohibition by some landlords.

They may also be necessary for people who have an allergy to conifers, and are increasingly popular in office settings [citation needed].

Feather trees

The first artificial trees were tabletop feather trees, made from green-dyed goose feathers wound onto sticks drilled into a larger one, like the branches on a tree.

Originating in Germany in the 19th century to prevent further deforestation, these “minimalist” trees show off small ornaments very well. The first feather trees came to the U.S. in 1913, in the Sears, Roebuck and Company catalog.

Modern trees

The first modern artificial Christmas trees were produced by companies which made brushes. They were made the same way, using animal hair (mainly pig bristles) and later plastic bristles, dyed pine-green in colour, inserted between twisted wires that form the branches.

The bases of the branches were then twisted together to form a large branch, which was then inserted by the user into a wooden pole (now metal with plastic rings) for a trunk. Each row of branches is a different size, colour-coded at the base with paint or stickers for ease of assembly.

The first trees looked like long-needled pine trees, but later trees use flat PVC sheets to make the needles. Many also have very short brown “needles” wound in with the longer green ones, to imitate the branch itself or the bases that each group of pine (but not other conifer) needles grows from.

These trees have become a little more realistic every year, with a few deluxe trees containing multiple branch styles and newly developed True Needle technology to more closely imitate nature.

Many trees now come in “slim” versions, to fit in smaller spaces. Most of the better trees have branches hinged to the pole, though the less-expensive ones generally still come separately.

The hinged branched trees just need for the branches to be lowered, but they are a little less compact. Better trees also have more branch tips, the number usually listed on the box.

Around 2003, some trees with moulded plastic branches started selling in the U.S. Now there are also upside down Christmas trees. These Christmas trees are advertised to “Give you more space for presents”.

Designer trees

The first artificial trees that were not green were the metallic trees, introduced about 1958, and quite popular through the 1960s. These were made of aluminium attached to metal rods, supported on wooden or aluminium central poles. Some were made with aluminium-coated paper, which was flammable.

These posed a great fire hazard if lights were put directly on them, particularly the relatively hot bulbs sold in that era; warnings to this effect are still issued with some Christmas tree lights. They were instead lit by a spotlight or floodlight, often with a motorised rotating colour wheel in front of them.

More recent tinsel trees can be used safely with lights, due to the use of flame retardant materials as well as improvements in the safety of the Christmas tree lights themselves.

Other artificial trees may look nothing like a conifer except for the triangular or conical shape. These may be made from cardboard, glass, plastic, or from stacked items such as ornaments. Such items are often used as tabletop decorations.

For further variations see Annual christmas trees exhibition at the State University of Arts and Design Karlsruhe, Germany

Outdoor trees

Outdoor branched trees made out of heavy white-enameled steel wires have become more popular on U.S. lawns in the 2000s, along with 1990s spiral ones that hang from a central pole, both styles being lighted with standard miniature lights.

These lights are usually white, but often are green, red, red/green, blue/white, blue, or multicoloured, and sometimes with a small controller to fade colours back and forth.

A few hotels and other buildings, both public and private, will string lights up from the roof to the top of a small tower on top of the building, so that at night it appears as a lit Christmas tree, often using green or other coloured lights.

Some skyscrapers will tell certain offices to leave their lights on (and others off) at night during December, creating a Christmas tree pattern.

Other gimmicks

Since the late 1990s, many indoor artificial trees come pre-strung with lights. Some are instead lit partly or completely by fibre optics, with the light in the base, and a rotating colour wheel causing various colours to shimmer across the tree.

In 2005 Upside-Down Christmas Trees became popular. They were originally sold as decorations for merchants that allowed customers to get closer to ornaments being sold. Customers then wanted to replicate the inverted tree.

Retailers also claimed that the trees were popular because they allowed larger presents to be placed beneath the trees. Upside-down Christmas trees come in three varieties: stand-alone, ceiling, and wall.

The stand-alone trees have a flat base. Ceiling trees have a base that can be bolted into a ceiling, and wall trees are generally half of a tree, that are bolted to a wall.

Past gimmicks include small talking or singing trees, and trees which blow “snow” (actually small styrofoam beads) over themselves, collecting them in a decorative cardboard bin at the bottom and blowing them back up to the top through a tube hidden next to the trunk.

A long-standing and simple gimmick is conifer seedlings sold with cheap decorations attached by soft pipe cleaners. Real potted ones are often sold like this, and artificial ones often come with a “root ball” but only sometimes with decorations.

Environmental issues

There is some debate as to whether artificial or real trees are better for the natural environment. Artificial trees are usually made out of PVC, a toxic material which is often stabilised with lead.

Some trees have a warning that dust or leaves from the tree should not be eaten or inhaled. A small amount of real-tree material is used in some artificial trees. For instance, the bark of a real tree can be used to surface an artificial trunk. Polyethylene trees are less toxic, though more expensive, than PVC trees.

Artificial trees can be used for many years, but are usually non-recyclable, ending up in landfills. Real trees are used only for a short time, but can be recycled and used as mulch or used to prevent erosion.[13] Real trees also help reduce the amount of carbon dioxide in the atmosphere while growing.

Live trees are typically grown as a crop and replanted in rotation after cutting, often providing suitable habitat for wildlife. In some cases management of Christmas tree crops can result in poor habitat since it involves heavy input of pesticides.

Organically grown Christmas trees are available in some markets, and as with many other crops, are widely held to be better for the environment.

Source: Wikipedia