Virginia Christmas Trees
By: Matthew Carroll (email)
Christmas trees in Virginia are a big agriculture crop every year with over a million trees being harvested throughout the state. The trees that are sold have a wholesale value of 20-40 million dollars. Christmas tree growers strive to produce trees that grow straight, have a cone-shaped form, good color, and are full or have no “gaps”. The trees are influenced by the grower to develop all these characteristics. This can be done by changing the environment or altering the genetic characteristics of the tree you plant.
A field of Eastern white pine Christmas trees and various other species
Christmas tree growers mainly influence a tree's environment by shearing.
Shearing removes the branch tips of the tree, much like a browsing animal might do. Heavy shearing is removing a lot of needles and branches, and light shearing does not remove as much.
By shearing a tree, a grower will modify the balance of growth regulators . One growth regulator referred to as an auxin reacts the most to the shearing process.
In pine species, when the tips of the branches on the tree are trimmed it allows dormant buds in the fascicles to form along the stem. This leads to more branches and needles which results in a full tree. This only occurs in pine species, not spruces and firs. However, when shearing is done on spruce and fir trees, the length of the leaders are controlled which increase the fullness of the tree.
The first step to shearing is to trim the tip of the tree to about 12-14 inches. Then trim the tree into a cone shape. A few shearing tools are clippers, shearing knife, and a Beneke (machine shearing). Watch the video below which shows machine shearing which is typically done on older trees.
download the clip showing the
Shearing of Norway spruce using a Beneke
(NOTE: Must use a media player such as RealPlayer; click for free download)
Another way Christmas trees are influenced is by controlling genetic factors. The best way to control genetic factors is through species selection. Some species grow faster than others and have different growth form, or grow well in certain climates. Another genetic trait is color. Color is determined by what type of genes the tree has; dominant genes or recessive genes .
Seedlings of several different species planted on October 29, 2005 at Claybrooke Farm
( Louisa County , Virginia )
Several different species are grown as Christmas trees in Virginia . A few types are eastern white pine, Fraser fir, and Norway spruce. All of these species are different and need to be managed differently. For example, Fraser firs are genetically fit for growing in the mountains, so growing them in the Piedmont and Coastal Plain of Virginia is difficult to do with any success. Eastern white pine and Scotch or Scots pine are very hardy species, which can grow statewide. These two pine species grow fast, only taking 6-8 years to reach 6 feet. Norway spruce is also a hardy species, but is sensitive to certain types of soil. As a result this species may take longer to reach 6 feet (8-11 years).
Fraser fir Christmas tree
Questions:
- What are three characteristics that Christmas tree growers want their trees to have?
- What is shearing?
- The growth regulator which reacts the most to the shearing process is
- What is one of the genetic factors that can be changed?
- Name three species of trees that are grown in Virginia for Christmas trees.
Answers:
Grow straight, have a cone-shaped form, and are “full” or have no gaps.
Shearing is the pruning of Christmas trees to form a certain shape.
Auxin
Species selection, specific traits, or different seedling sources.
- Fraser fir, Eastern white pine, Scotch or Scots pine, or Norway spruce.