Considerations When Planting a Living Christmas Tree

Many people find the idea of planting a live Christmas tree appealing. Watching a young tree mature in the landscape can be enjoyable and can bring back pleasant memories of family holiday gatherings. However, without some preparation and precautions, the tree may not survive to provide such benefits. Following are a few suggestions to increase the likelihood of success when planting a living tree after Christmas.

First, consider whether the proposed planting site is suitable for planting an evergreen tree. In general, conifers do not tolerate poorly drained soil conditions. Never plant a pine in a location where water stands after a rainfall event for any period of time. Even if the site is sloped, a pine tree will generally not thrive in a heavy clay soil. In some cases, the only practical solution is to create a berm or mound of topsoil to assure good drainage. If the soil is suitable, be certain that there is sufficient space for the tree to develop. In general, pines should be planted no closer than 25 feet from other trees, unless they are planted in a row as a windbreak. Pines need full sun and will become lopsided if shaded by other evergreen or deciduous trees. Also, poor air circulation due to crowding can increase the likelihood that the tree will be affected by fungal needle blight diseases.

The species of conifer selected is an important consideration. While Scotch pine is excellent as a cut tree, it is highly susceptible to a disease called "pine wilt" and is therefore not recommended in Missouri as a landscape tree. Pine wilt, caused by a nematode, does not affect young trees. However, there is a high probability that a Scotch pine will succumb to the disease before it reaches the age of 20 or 25 years. While white pine has no serious pest problems, it is less tolerant of poorly drained soil conditions than Scotch pine and is, therefore, not likely to live long in a site with heavy clay soil. If planting a spruce or a fir, make certain that the species is suited to our climate. Although fraser and balsam fir are cold hardy in Missouri, they are not tolerant of our summer heat. White fir (Abies concolor) is probably the species of fir best suited to Missouri conditions.

If the site and space are appropriate for a pine tree, there are several precautions that should be taken to maximize the chances that the living Christmas tree will survive after planting in the landscape. It is particularly important that the tree be held in the house for no more than about one week. The warm, low humidity environment in the house causes excessive moisture loss from the foliage and the soil ball and makes the tree more susceptible to winter injury after planting. Keep the tree outside, or in an unheated garage until a few days before Christmas, making certain that the soil ball remains moist by covering it with mulch and watering occasionally if necessary. If the ball seems dry, it may be necessary to place it in a tub with 2 inches of water in the bottom to re-hydrate it. Dig the planting hole before bringing the tree in the house. The hole should be 2-3 times the diameter of the soil ball, but no deeper. Cover the hole and excavated soil (placed on a tarp) with a thick layer of straw to keep it from freezing. When the tree is brought inside, place it on a heavy, waterproof, plastic tarp, propping the ball in an aesthetically pleasing position with bricks of concrete blocks. Cover the ball with wet burlap, enclosed in plastic sheeting to keep the ball from drying excessively. If the tree is held in the house for more than a few days, it may lose up to 10 gallons of water from the soil ball through transpiration from the needles. Consider watering the tree by placing a gallon milk jug with pin holes in the bottom on top of the ball and filling it several times.

It is best to plant the tree as soon as possible after Christmas. However, in some cases, the weather will not be conducive to planting. It is important to keep the tree in good condition until planting conditions improve. If it is bitter cold and windy, consider placing the tree in an unheated garage where the temperature is 30 to 50 degrees F. until conditions improve. Do not simply take the tree outside and leave the soil ball exposed. This may lead to excessive drying or to death of roots in the ball from freezing. If space is not available in a building, place the tree outside in a location sheltered from the prevailing wind and mulch the soil ball heavily to keep it above freezing.

When planting time arrives, good planting technique will increase the chances of success. Take care not to damage the soil ball. Move the tree by placing it on a strip of burlap or tarp and using one person at each of the four corners to transport it to the planting site. Place the tree in the hole carefully, making certain that the ball sits on hard soil and that the top of the ball is no lower than the soil surface. If amending the backfill soil, do not use more than about 20% compost or peat moss. Fill the hole partially with the excavated soil. Then, remove all rope or twine from the trunk and peel back the burlap, so none will extend above the soil after planting. Finish filling the hole with soil, tamping as you go, to establish good contact between the ball and the backfill. When backfilling is complete, pour about 10 gallons of water onto the loose soil. Finally, add 3 to 4 inches of mulch. If the tree is planted in a location exposed to strong winds, secure it with stakes or guy wires, using straps or rubber hose to protect the trunk from damage. Write a note on your 2004 calendar to remove the supports from your tree 8 months after planting.

Chris Starbuck, Woody Ornamental Horticulture, UMC (573)882-9630