Basal pruning has been one of the most controversial Christmas tree culture methods, 

 and results of this study illustrate why. Even though all five of the different prun- 

 ings substantially reduced the height growth (which presumably makes the crown appear 

 denser), there appeared to be no corresponding overall increase in number, quality, or 

 size of merchantable Christmas trees during the 10-year period. However, there did 

 appear to be a trend toward increased production during the first 5-year period on trees 

 that had been moderately pruned. 



Douglass (1963) also found that height growth could be reduced by pruning. How- 

 ever, he cautioned that pruning is frequently overdone on lower-quality sites and 

 results only in increasing the time required to grow a merchantable size tree. 



Height growth and the corresponding internode length are generally not excessive 

 on most sites suitable for Christmas trees in Montana. Areas where annual growth of 

 most of the trees exceeds 16 inches are probably better suited for growing timber than 

 they are for Christmas trees. However, pruning can be used to reduce the length of 

 the internodes where height growth is excessive on areas dedicated to Christmas tree 

 production. 



Where pruning is needed: 



1. Prune from the middle of the green crown, leaving two or three good whorls of 

 lower branches for subsequent stump culture. 



2. Prune at the following rates: 



If 



Actual growth exceeds 

 desired growth by 

 (Percent) 



Then 



Remove the following 

 amounts of green crown 

 (Percent) 



25 

 50 



75 

 100 



33 

 50 

 60 

 66 



3. Prune as often as necessary to maintain the desired internode length. 



4. Shear to shape and increase the density of the crown. Kintigh (1965) found 

 that shearing was one of the best cultural methods to use for increasing the quality 

 of Douglas-fir Christmas trees. 



5. Harvest cultured areas annually to assure maximum utilization of trees when 

 they are ready. 



6. After harvesting, culture the stump for branch turnup development. 



Douglas-fir thickets provide an extensive source of small, medium-quality Christ- 

 mas trees in Montana. For example, about 8 percent^ of the trees in the original stand 

 used for this study produced merchantable trees during the initial thinning or during 

 the following 10-year period. However, over 95 percent of the trees were 2- to 4-feet 

 tall and of standard quality or less. 



^This is equivalent to about 1,000 trees per acre in the thickets but because the 

 thickets are clumpy, the average per acre for an area as a whole would be considerably 

 less . 



15 



