One of the more enjoyable Christmas traditions is to replant a living Christmas tree into your landscape after the holiday season. Living trees are usually purchased as containerized trees grown in pots or as "balled and burlapped" (B&B) trees with a field-dug root ball bundled in burlap or other fabric. Containerized trees are usually smaller and target the “tabletop” Christmas tree market. Following use as Christmas trees, they are planted into the landscape.
Unfortunately, trees replanted after holiday use often do not survive or grow well. Most problems can be traced to four major factors: 1) The tree species selected may not be adapted to the climate where the tree is planted; 2) Too large a tree will suffer a greater degree of transplant shock than a smaller tree; 3) Often while in the home, the tree is allowed to dry out between watering to the point where it cannot recover; and 4) Finally, a Christmas tree is often displayed in the home long enough to lose winter hardiness after which it succumbs to freezing temperatures when planted outdoors.
The most popular species for living Christmas trees in North Carolina are Fraser fir, white pine, and the Norway, white and Colorado blue spruces. All of these trees are native to either the mountains or more northern regions of the United States, and therefore not generally adapted to the lower elevations of the state. Christmas tree species which are more suitable to the remainder of North Carolina are eastern redcedar, Leyland cypress, Virginia pine and varieties of Arizona cypress such as 'Blue Ice' and 'Carolina Sapphire.'
Though very popular as a cut Christmas tree, Fraser fir is not recommended as a living Christmas tree to be planted in the landscape. In North Carolina, Fraser fir grows naturally in fertile soils at elevations of 4,500 feet and above and is typically cultivated at elevations above 3,000 feet. Fraser fir will not likely survive more than a few years if planted at lower elevations. High summer temperatures and drought stress impede normal growth and cause increased problems with pests. Heavy clay soils lead to further difficulties in establishing Fraser fir. Even in western North Carolina where Fraser fir is grown as a Christmas tree, Fraser fir has problems with the balsam woolly adelgid, which will either kill the tree or cause it to lose its beautiful Christmas tree shape. Further, Fraser fir does not transplant well because of its poor rooting habits. Of the firs grown in western North Carolina, Canaan fir transplants much better and looks much like a Fraser fir.
Best white pine growth in North Carolina may be expected between 1,200 to 3,000 feet in elevation on cooler, north-facing slopes, in coves, and along stream bottoms. As with Fraser fir, white pine has a limited life expectancy if planted in the lower Piedmont and Coastal Plain, especially on clay soils.
The spruces may survive many years when planted out of their natural range, but often lack normal vigor and growth. Norway spruce usually performs better than the other spruces when planted on marginal sites.
The firs, spruces, and white pine will all perform best when planted in a cool area out of strong winds. The site should have sufficient moisture, but it should not stay wet for prolonged periods. Also consider that these trees grow very large, and if they survive for many years will require room to grow.
Leyland cypress, Arizona cypress, Virginia pine and eastern redcedar are all suitable for the Piedmont and Coastal Plain areas of North Carolina. These species are adapted to a wide variety of sites and tolerate warmer climates. However, they require more shaping than the "mountain" species to retain their Christmas tree appearance.
In addition, small, living conifers are available at many retail stores. These can be various species including dwarf Alberta spruce, Norfolk Island pine, Italian stone pine, false cypress also known as Lawson or Port-Orford cedar, and even rosemary (which is not a conifer but is an herb). Some of these can be planted in North Carolina and others can’t. Be sure to read the tag that accompanies the plant to look for further information, especially the planting zone. If the trees were grown in a greenhouse, they may lack any winter hardiness at all and will need to be kept inside until spring when the danger of frost is over. Due to the small container size and the coarseness of the often root-bound media, these trees can be especially difficult to keep watered and alive for outdoor planting.
Trees destined for the landscape should not be larger than five to six feet in height to provide for a sufficient root ball and to facilitate handling. Minimum standards recommended by the American Landscape and Nursery Association suggest that a 5 foot pyramidal conifer should have 22 inch diameter root ball to survive transplanting. Smaller root balls will not provide adequate moisture uptake to sustain the crown of a typical Christmas tree.
Once selected, Christmas trees must be properly maintained. Trees should be placed in a cool spot in the house, away from heat or direct sunlight. Small, low-temperature electric lights should be used for decoration rather than any older-style, heat-generating incandescent bulbs. Reducing home thermostat settings a few degrees (especially when the room is not occupied) can also slow the rate of drying.
Both B&B and container trees need to be watered regularly but not flooded with water. If a deep tub is used to contain the B&B tree, there should only be an inch or two of water at the bottom – do not fill it to the brim like the bowl of a cut Christmas tree stand. Roots need to breath. One technique for watering living trees while they are displayed indoors is to periodically distribute crushed ice over the top of the root ball. Moisture retention of your tree can be further improved if you spray a light mist of water on the foliage (if that can be done without damaging ornaments or risking electrical shock). A full size tree can use as much as a gallon of water in a day.
If you do not have an adequate water-tight container in which to place the tree, you can wrap it in heavy plastic sheeting. Center the tree on a square of plastic, wrap it from the bottom, and leave the top open to breath. You should be able to water the tree without any water reaching the floor or table. Care should be taken not to over-water any tree.
Trees also have a better chance of survival if they are not displayed in the house for more than a week to ten days. Extended exposure to indoor temperatures can counteract winter dormancy in conifers. If the trees are set outside into severe cold after acclimating to indoor temperatures, they will exhibit winter injury in the form of foliage burn and bud abortion. Different storage techniques to re-acclimate trees to outdoor temperatures are marginally effective if dormancy is already broken. However, if the ground is frozen when the tree needs to be moved outside, store the tree in an unheated area such as a garage or outbuilding that is protected from the wind until it can be planted (and don’t forget to keep it watered). A short display period and prompt planting is the best way to insure a tree’s survival in the landscape.
To plant, till an area four to five times the size of the root ball to a depth of six inches. Dig a planting hole the same diameter and slightly shallower than the root ball or container size. Natural burlap can be left on the ball, but remove treated burlap or nylon and of course remove the plastic container. If a containerized tree is root bound, break up or divide any coiled or massed roots on the outside of the root system. Level the surrounding soil with the top of the roots. After planting, spread two to three inches of mulch over the disturbed area. If the tree is in a windy location, tie and stake it to keep it from blowing over. Water the tree after planting, but wait to fertilize it until spring after the tree has started to grow. Do not over fertilize in the first year, especially with nitrogen, until roots have had a chance to become well established.
The above procedures only get a living Christmas tree into the landscape. Other cultural practices are necessary if the planted tree is to thrive in its new environment. These practices include soil management (mulching, irrigation, fertilization, etc.), insect and disease management (identification, treatment decisions, and control), and periodic shaping to maintain the "Christmas tree" look. A homeowner must be willing to invest in ongoing maintenance to keep their tree beautiful. However, individuals who are successful can point with pride at their efforts, which will always remind them of the holiday season when the tree was planted.
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Publication date: April 23, 2014