You can buy "live trees" _ they come, with roots, in a pot of earth, so you can plant it after Christmas. You definately have to keep the earth moist, to keep the tree alive, until it gets planted. Most trees however are sawed off from their roots. You can just take two boards & nail them into the bottom of the trunk in the shape of a cross, so the tree stands up, but it is impossible to water the tree, so it won't last very long that way. It is better to get a Christmas tree stand. When putting the tree into the stand, it helps to place pennies between the trunk & the screws, otherwise the screws will dig into the trunk. It helps to have two people putting up the tree together, one to hold it steady while the other is underneath tighening the screws. Keep the basin full of water , replenishing it as needed, so it doesn't dry out to badly. A dry tree, besides loosing needles & not looking good, becomes a fire hazard!
at 10:36 AM on Nov. 24, 2010