No matter how carefully you plan, plant and maintain your Christmas tree plantation, chances are you will end up with some trees that you think you cannot market as trees, You may or may not be right because consumer preference for Christmas trees varies tremendously. Some like their trees tall and slender, some like them short and fat. Beauty, truly, lies in the eye of the beholder! And although the USDA has established standards, (USDA U.S. Standards for Grades of Christmas Trees, 1990 (See FOR-34), many trees not classified as "premium" trees are still salable in the retail market.

Decorations
However, if you truly have trees that will not sell as trees, do something else with them. so that you can profit from your work in raising them. The most common alternative use is to make wreaths of the greens from these trees. Greens from a standard 6 ft tree can probably make 2 or 3 wreaths. When such wreaths are conservatively priced at $10 apiece, the tree can actually be more profitable as wreaths than as a tree. Use decorations that are typical for the region -- holly is fairly common in Kentucky, for example; you could put sprigs of holly in the wreaths -- seaside places use shells! Several companies manufacture a variety of wreath-making equipment and supplies, ranging from around $50 to well over $1000. Before investing in anything, watch an equipment demonstration and learn as much as possible about it. Both equipment and demonstrations are usually found at state and regional Christmas tree grower meetings. See FOR-34 for information on Christmas tree grower associations. Some growers have easily paid for their equipment with the results from one seasons work.
Other options include roping, swags (a bundle of several branches tied at the branch end and fanned out--usually with a bow at the top and sometimes with other bows, pine cones or other ornaments in the greens), grave blankets, and other displays (e.g. centerpieces for tables) made of greens and other decorations. You can even simply bundle the greens from unusable trees and from the bases of good trees and sell them by the pound or bundle for consumers to use as they please for decoration.

Models
Another way of using trees with marginal quality is to cut one or two, mount them in stands, and decorate them for consumers to see. as they come in. Often an odd tree looks just fine when covered with shiny ornaments and tinsel. You could also decorate one for birds and other wildlife with strings of cranberries and popcorn and balls of suet and peanut butter.
Trees that grow a bit too fast and become outsized can be topped to make a pretty, small, tabletop tree. Some growers have been very successful with tying two small spindly trees together to make one larger, fuller tree. Once decorated, no one knows the difference. Trees with a flat side could be advertised as ideal for a small apartment, because they sit closer to the wall than a regular symmetrical tree; trees with two poor sides could go in corners, etc. As the old saying goes, "If you're given lemons, make lemonade!"
The basic message here is that you have invested much time, money and energy into growing your Christmas trees. If you are to optimize your return on investment, you should consider all options for utilizing all that material for your benefit.

*The word cull in forestry usually describes a tree that for some reason--species, location in the forest structure (understory, overstory), shape quality -- is undesirable and therefore should be removed. Quotation marks are used here because the word is used somewhat differently.