I start a jar about every three days for a regular supply. They could be kept refrigerated for a short while but would still need to be rinsed daily. If you wish to buy a living Christmas tree that can go into the garden after the holidays, shop early and pick one out at your nursery. The nurseries may carry Colorado blue spruce, dwarf Alberta spruce, Monterey or Aleppo pine, and the giant sequoia. It is better to use these just outside the living-room window rather than inside where they may be endangered by warm, dry air.
Some care is necessary to prevent a living tree from dying indoors.
Keep them outside as long as possible. Hose it down, or better yet, spray the needles with an anti- transpirant. Check the soil moisture daily. After the holidays, move it to a sheltered porch or carport and protect the root ball from freezing. Allow a week or so for the tree to adjust to the temperature change, and then plant as soon as possible.