Buy your Christmas greenery fresh. When selecting to purchase any type of greenery, always look for a rich green color in the needles. A faded dull green color is usually an indication the greenery is losing freshness. Running your hand vigorously over branches where the needles do not shed is a good sign of freshness. For Christmas trees, maximum freshness is indicated by branches that are firm and springy. If you can, find out when the trees were cut and the greenery was made as you would ideally purchase items that had been harvested as recently as possible.
Avoid placing greenery in locations where it is exposed to direct sunlight for long periods of time. The ultraviolet rays of the sun can quickly dry and brown any tree branches and needles it comes in contact with. Also try if possible to keep greenery from very warm locations such as a vent, stove or fireplace as this can cause rapid drying.
Just before bringing your real Christmas tree in to the house, spray it down with a water hose and let it soak in the moisture for a few hours. Make sure to freshly cut the base of your Christmas tree to open it up to drink water within a day before placing in the stand. Trees drink up a lot of water, so constantly check and refill the water in the tree stand so it can continually drink.
Spray indoor wreaths, garland and other greenery with a hand held mister once on a weekly basis. The wreaths and garland are made from the tree branches and so just like the trees they also need to soak in water. Outdoor greenery should also be watered weekly and can be done using a water hose. Greenery exposed directly to sunlight should be water twice a week or more.
It is best if possible when watering trees and greenery to use spring or well water. Chlorinated water which is often present in municipal water supplies can actually dry the greenery out somewhat. If chlorinated water is all you have, by all means use it just make sure to use it more often to minimize drying effects.