Nitrogen application for Fraser fir

Application of commercial fertilizer materials has become an essential part of plantation management for many Christmas tree producers. Soil testing, foliar analyses and observance of tree growth and response are all used in establishing the need for fertilization in Christmas tree plantations. The potential exists to improve the growth and quality of many Christmas tree species through fertilization. However, for fertilization to be most effective, other environmental factors affecting tree growth such as the right site for the species, soil moisture considerations and effective weed control need to be in place.

Growers have used several approaches to nitrogen fertilization depending on their objectives and the particular site. One common approach is to make annual applications of about 40 to 100 pounds of actual nitrogen per acre after the first or second year of growth depending on height/age of the tree. Timing for this application should be about two weeks prior to bud break. Also, foliar analysis this fall can help you gauge if your nitrogen program should be adjusted.

Table 1 shows the recommend rates for nitrogen applications.

Pale green to yellow foliage generally more on older foliage but trees will show a general overall color loss. Note: Off-color trees can also be an indicator of the pH being too high. Photo credit: J. Shelton, North Carolina State University.

Table 1. Annual application rates for nitrogen (amounts of actual nitrogen)

Planting year No nitrogen recommended
Year 2 ½ oz./tree     ( 38 # per acre)*
Year 3 ½ oz./tree     ( 38 # per acre)*
Year 4 1 oz./tree ( 75 # per acre)*
Year 5 plus 1 oz+/tree     ( 75 # + per acre)*
Year of harvest 1 to 5 oz./tree   (part in August for color depending on size of tree)

*Based on 1,200 trees per acre.

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