Ohio Christmas Tree Producers Manual

Bulletin 670

Spacing Within and Between Rows

One of the most frequent questions asked by a person just getting into the Christmas tree business is, "What spacing should I use in my plantings?" It is also a question for which there is no simple answer. Obviously, spacing should be kept to the minimum possible so that the greatest number of trees can be grown per acre. The total number of trees planted on a farm dictates equipment needed for mowing, spraying, etc.

Spacing Within Rows of Trees: Spacing within rows is usually determined by species characteristics and the size to which they will be grown. Pines generally have relatively broad crowns (Figs. 5 and 6). A spacing of 5 to 6 feet between trees within rows is needed if trees are to be grown to a height of 6 to 8 feet. Spruces, true firs and Douglas- fir usually have narrower crowns (Figs. 10 and 12), thus, a spacing of 4 to 5 feet within rows should be adequate for growing 6- to 8-foot trees.

Spacing Between Rows of Trees: Spacing between rows of trees is governed by species characteristics and equipment to be used in operations. Row widths should be at least 2 and preferably 3 feet wider than the widest piece of equipment that must travel between the rows. If mechanical diggers will be used in the future, extra space is needed to maneuver the tractor and digger. Once trees are planted, spacing is set, and efficiency of operations will be affected for at least the time needed to grow one crop of trees and longer if new seedlings are replanted (interplanting) as older trees are harvested. Consideration should be given not only to what type of equipment is to be used immediately (often determined by what is on hand or what is least expensive) but also to what will probably be used in the future. Spacings are often set at 5 to 6 feet between rows to accommodate self-propelled, non-riding type mowers. The grower may soon find such mowing to be too time consuming and exhausting to allow for efficient management (Fig. 22). In the past it was often difficult to change to other types of mowers because of limited alternatives (such as brush-hogs), and those available were often too wide to fit between the rows without injuring the trees. If large tractors and trail-behind mowers are used, spacings of 7 to 9 feet between rows are required, with a corresponding decrease in the number of trees grown per acre. This problem has been greatly alleviated by the introduction of tractors having not only narrow axle widths (for which 5 to 7 foot spacing may be suitable) but also sufficient power to operate mowers, sprayers, diggers, etc. (Fig. 23).

Fig. 22: Mowing for weed control with one of the many types of "walking" mowers. With such equipment, spacing between rows of trees can be closer, but labor requirements are higher.	Fig.23: Mowing with narrow width farm tractor. Such tractors speed up the operation and reduce the amount of space required between rows of trees.

Trees Per Acre for Different Spacings: As noted previously, spacing should be minimized to that needed to accommodate species-equipment combinations being used. Wider spacings reduce the number of trees that can be grown on each acre and increase operational costs per tree for many cultural practices such as mowing, chemical weed control, etc. The number of trees that can be planted per acre using different combinations of spacing, independent of access roads, harvest lanes, buffer strips, etc. is presented in Table 5.