Each year in the US, more than 35 million Christmas trees are harvested. This tradition, dating back to the 16th century in Strasbourg, Germany (now part of France) has continued and thrived into the 21 century. The first retail offering of the Christmas tree was in New York City in 1851. Each year, since 1966, the National Christmas Tree Association provides the first family with a fresh, renewable tree.
Christmas trees are renewable, unlike their artificial counter parts make of petroleum or plastic. In fact, each year more than 59% of trees sold are recycled by community programs into useful mulch for our flowers and trees. Here are some other ways to recycle your tree. Christmas trees are also renewable, because every spring growers plant more than 56 million new seedlings. For more information visit the National Christmas Tree Growers Association's website.
Living Christmas trees that can be planted in the yard after the holiday have also become popular.
Iowa has approximately 200 growers, producing trees both for retail lots and choose and cut operations. Popular species include Scotch pine, white pine, red pine, balsam fir, and Fraser fir. For the grower, the sale season is not the only busy time of the season. Growing Christmas trees is a year round plan of action. Visit the Department of Agriculture Iowa Christmas Tree Directory to find Iowa growers.
Trees must be planted every year. Starting in the fall, growers do their site preparation, getting the site ready to plant, using tillage or herbicides to remove competing grasses and weeds, contact nurseries and order their planting stock. In the spring during April, trees are either hand planted or with larger growers planted with machines. Hand planting involves using tree planting bars, shovels, or spades to plant the trees, making sure they are planted at the right depth and straight to produce a high quality tree. After planting, growers must apply a layer of organic mulch for weed control or use one of the registered herbicides to prevent weed and grass competition during the growing season. Weed control is required every year on every tree until they are marketed.
During much of the spring and summer the trees must be monitored for insect and disease problems. Common insect pests for the Iowa grower include pine needle scale and European sawfly; common diseases are brown spot and Lophoderium needlecast. In addition the growers face other biological obstacles including deer, gopher, ground squirrels, mice and voles. Birds cause deformed leaders by perching on them as they expand in the spring. Weather and climate also have impacts including damage from too little or too much precipitation, winds, ice and snow.
Newly planted trees may require staking to correct leaning trees and correction of multiple leaders during their first three years. In June and July, starting 2 to 4 years after planting, each tree is sheared to control their growth, shape, density and form. Growers may thin the number of shoots in each tree and control the expansion of the leader to produce trees which have desirable density of leaves and branches.
Terminal growth is limited to develop trees with greater density and symmetry. Trees are shaped with either shearing knives or mechanical shears or trimmers to produce that ideal shape for a Christmas tree which is twice as high as wide. Quality shearing produces quality trees and is one of the most important cultural practices in the production of Christmas trees; it is also the most labor intensive cultural treatment. Growers may also basal prune each tree, allowing for easier harvesting and providing a branch free handle for the consumer.
Some species of trees produced in Iowa require a application of a tint and anti-desiccant to maintain their good green color during the Christmas season. These dyes are normally applied with mist blowers or hand sprayers during September to November.
Starting in October, growers get ready to market their product. Most Iowa trees are sold in the field as choose-and-cut operations. These trees are tagged, graded and priced. Christmas tree growers are responsible for advertising their product, providing access to the plantings and helping the consumer harvest their perfect tree. This may involve providing shakers to help remove old needles, Christmas tree bags or bailers to get the tree home and into the house. Wholesale growers are usually responsible for harvesting each tree, shaking, bailing the tree and in may cases delivery of the trees to the retail lots in towns and communities.
Shearing Christmas Trees
Shaping or shearing of conifers is required to produce a salable Christmas tree in Iowa because consumers demand that the tree have uniform spacing between branches, dense foliage and a symmetrical shape.
During the first 2-3 years after planting, shearing involves pruning of multiple leaders. Shearing for shape and density begins as soon as annual growth rates exceed 10 to 12 inches per year. Shearing then continues every year until the tree is marketed.
Correct timing is critical for proper shearing. Spruces and firs can be sheared any time during the year, but the best time to shear is from September to March. This extended shearing time is possible because these species produce auxiliary buds along the stems and branches as the tree grows. These buds are fully developed and form bud clusters whenever the stem or branch immediately above them is removed.
Pines are sheared during the active growing season, usually June through July. Pines do not form axillary buds, and will form a cluster of buds when sheared at the correct time. If sheared too early, growth may continue resulting in too much distance between branches; pines sheared too late may result in no bud set, fewer buds or dieback of the terminal leader.
During shearing, cut all side branches necessary to give the tree the desired shape and taper. Desired taper varies from 1/2 to 2/3 as wide as the tree is tall. Shearing should be done only on the current years growth.
Several different tools can be used for shearing including hand clippers, hedge shears, power trimmers and shearing knives. Hand clippers are slow but precise and are most useful when shearing spruces or firs when shearing back to existing buds. Hedge clippers are faster but require more energy to use for long periods of time. Shearing knives, sharp, smooth or serrated blades 12-20 inches long, are perhaps the fastest but most hazardous; guards must be used for maximum safety.