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 color and scent; but species in other genera are also used.

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.

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.

Artificial trees have become increasingly popular, as they are considered more convenient and (if used for several years) less expensive than real trees. Trees come in a number of colors and "species", and some come pre-decorated with lights. At the end of the Christmas season artificial trees can be disassembled and stored compactly.

Adding a Christmas tree to an exterior decoration always enhances the overall aparience of the house and if the tree is of a non standard height the decoration quality will go to an higher level.
Using your garden's trees is always a good idea. Just look for broken branches and unsafe spots before working around or placing lights or electrical wires. Whenever you are unsure about an installation just remove it to be on the safe side. You can also ask a competent electrician to check your installations before you light them up or ask the fire departament to inspect your electrical decorations for you.