'Tis the season when many of us bring an evergreen tree into the house and make it the center of attention for a couple of weeks. With its lights, glass ornaments, icicles and popcorn strings, the tree becomes a glorious treat for the eyes. But how about having a tree that will live beyond the holidays?
Living Christmas trees can provide the best of both worlds. I must admit, I always feel a little guilty with a typical cut Christmas tree. Yes, I know the cut ones are raised on farms specifically for that one purpose. Still, it kind of feels like a waste cutting down a tree and only keep it for a short time before throwing it in the trash. In my rebellious youth, I would decorate my Ficus benjamina (weeping fig tree) for December, and then I'd have a nice big houseplant for the rest of the year. But now that I've turned into a traditionalist, it must be an evergreen tree for the holidays, and keeping a tree alive feels better, to me.
That doesn't mean it's for everybody. Like every other living thing, a living Christmas tree requires some care. You can't treat it the same as one that's been cut, so let me run through a few pointers to help you make your choice. What kind of tree would you want? If you'd like a one to remain indoors in a pot, you can consider a Norfolk Island pine. Just make sure it gets enough humidity, or it can fall prey to spider mites.
For outdoors, you want a tree that can survive the challenging climate here in southern Nevada. There are several well-adapted trees that naturally have the customary pyramid shape: Mondale pine, Aleppo pine, incense cedar, and western juniper all do very well in this climate. They can grow to be over 40 feet tall in time. Hemlocks don't perform well here in Southern Nevada; it's too dry and hot. The only fir tree I could find that seems to be a good bet for the region is Spanish fir, Abies pinsapo, which only slowly reaches 25 feet in height.
Since the point of having a living tree is to maintain it through the holidays so you can plant it afterwards, how do you keep it alive?
First, just as with any other plant, make sure the tree is healthy before you buy it. Look at the needles. Are they green and well attached? You shouldn't be able to shake a limb and get a shower of dead needles. There shouldn't be holes in the limbs or trunk. That could indicate borer damage. You shouldn't see signs of insects.
Second, don't get too large a tree. Anything over six feet tall is susceptible to transplant shock when you put into the ground. Six feet or smaller is key. Also, a living six-foot Christmas tree with soil and root ball weighs more than 100 pounds. I'm buying a heavy-duty plant tray with casters.
Only keep your living Christmas tree indoors for a week to 10 days. If you can keep it at the nursery until just before you want to put it up, that might be best. You see, when the days become shorter and cooler, as in the autumn, many plants, including evergreens, go dormant. That long winter's nap you've heard about. Inside your house, it's probably light for fifteen or sixteen hours every day, and it's most likely warmer than outside. Even though it's alive, you don't want to wake up the tree until after it's been planted outside. Otherwise it gets confused and behaves as if it were spring. It will try to produce new leaves without having the necessary resources. This is one reason that living Christmas trees sometimes don't make it. Another reason they sometimes are unsuccessful is that the root ball dries out. Definitely keep it watered. Use the smaller lights that don't produce as much heat. Place it away from heat sources like radiators, vents and fireplaces.
When the holidays are over and you want to transplant the tree outside, you might need to reacclimate it. Put it in a garage or other sheltered spot for a few days before bringing it outside.
Planting your living Christmas tree is pretty much the same as planting any other tree. Find a place where the tree will look good when it's fully grown. Dig a hole as deep as the root ball but at least three times as wide. The day before you want to plant, fill the hole with water. The water should drain completely overnight. If not, find another place, because without good drainage, plants can't survive. If the root ball is wrapped in plastic or treated burlap, remove the wrapper. Loosen the roots and stand the tree up in the hole. Back fill with the soil you took out, tamping it down to remove air pockets. Water it thoroughly and patiently wait for it to grow.
For KNPR's Desert Bloom, this is Dr. Angela O'Callaghan of the University of Nevada Cooperative Extension. Enjoy your holidays.