The only maintenance that artificial evergreen tree requires is an occasional cleaning to look fresh and natural.
If the fake evergreen tree is just dusty, a quick, once-monthly wipe down with a damp cloth should do the trick. Alternately, a pressurized air can take care of dust in just a few seconds.
If the plastic evergreen tree requires heavier dirt removal, grab an absorbent cloth and some window cleaner. Spray the entire plant or tree and allow the cleaner to sit for about 30 seconds.
Wipe the faux evergreen tree down with your cloth and go back over any areas that did not come perfectly clean. While this might take five minutes a month, it is cheaper and quicker than caring for a real evergreen tree.