With the surge in environmentalism, many people are trying to decide which is “greener,” a real Christmas tree or an artificial one. Both have their pros and cons. There is, however, a third alternative. You can decorate a still-living tree this year.
Most nurseries and garden centers sell potted Christmas trees. You bring them indoors for a brief spell (a week at most) during the holidays, then plant them permanently in the ground.
Still-living trees cost more. No one wants to pay a premium for a tree that still has roots, only to have it die after moving it outside. While planting a Christmas tree isn’t difficult, you should do the same research and preparation that you would do when choosing any tree for your yard.
First of all, make sure you have the right tree for the right place. Consider how the tree will fit into your overall landscape plan. Most evergreen trees get very large. That cute three-foot fir may have a mature height of 70 feet or more! Instead of trying to cram a giant into a small suburban yard, choose a dwarf specimen instead—or arrange to plant it elsewhere so it will have room to grow.
Consider the moisture needs of the various conifer species. Spruce trees naturally grow at higher elevations, where the ground is damp. Ponderosa Pines are able to withstand considerable drought. Planting a Piñon pine in your lawn will doom it to death by drowning. CSU Extension’s fact sheet on Evergreen Trees is a good place to begin your research.
Secondly, since the ground is frozen throughout much of the country at this time of year (and certainly here in Colorado), you must plan ahead and prepare a hole ahead of time. Excavate no deeper than the expected rootball, but at least twice the diameter of your tree—the wider, the better. Amend the soil as needed, and then cover with a tarp and one to two feet of mulch (such as bagged leaves or straw) to keep the soil workable.
If you didn’t dig a hole earlier this fall, you can attempt to keep the tree in its container until spring. Place it in a sheltered spot outside and mulch around the pot to simulate the insulation the ground would otherwise provide. Keep it damp, but not at all soggy, and plant as soon as the ground can be worked.
Going from sub-freezing temperatures to a warm living room, and then back outside again, is enough to shock even the sturdiest tree. Besides the wild swings in temperature, humidity also varies considerably. It’s best to move your tree gradually. If it’s outside when you buy it, put it in the garage for a few days to help it adapt to warmer temperatures. When you do bring it inside, be diligent in keeping the soil damp but not soggy. Keep the tree out of drafts and in bright light, but not against a window where the glass-focused sun will burn it.
After Christmas, reverse the process to allow your tree time to adapt to winter again. You have to convince it that spring is still a long way away. Prolonged exposure to warmer temperatures will cause it to lose hardiness, and it could freeze to death when placed outside.
Once your tree has been hardened off, it’s ready to be planted. Set the rootball on the firm soil in the hole you dug earlier, making sure that the root flare (where the trunk widens at the base) is above ground. Backfill with the amended soil, and mulch over the roots. Make sure the trunk has no mulch touching it, to keep both rot and voles from damaging it. Unless absolutely necessary, do not stake your tree. Water to settle the soil and provide moisture, but don’t saturate the dirt, as the roots need air to “breathe.” If snow doesn’t do the job, water again whenever the soil under the mulch starts to dry out. In our dry climate, it’s a good idea to spray your new tree with a product designed to reduce winter desiccation.
If you plant your tree where it can easily be seen from the street or house, you can avoid the whole yearly fuss, and simply decorate it outside for years to come. Nuts, birdseed “ornaments,” and strings of cranberries and popcorn are both festive and a treat for wildlife. Maybe that’s how to have the greenest tree of all.
For further reading, check out the CSU Extension fact sheet.