Ohio Christmas Tree Producers Manual

Bulletin 670

Plantation Establishment and Management

Preplanting Land Preparation

A number of major problems that can impede efficiency of operations in Christmas tree plantations can be prevented if consideration is given to land and site preparation before planting.

Bulldozing: Special attention should be given to removal of major obstacles such as large trees, rocks and unneeded fences that interfere with efficient operations. Removal of these materials, as well as heavy concentrations of medium to smaller trees and brush, can best be accomplished using heavy equipment that would be difficult to use once seedlings were planted (Fig. 14). When sites are to be bulldozed, the blade should be maintained just at ground level. If the blade is only a few inches above the ground, much of the smaller material may be matted down, and roots will not be pulled from the soil. If the blade is positioned too low, valuable topsoil may be removed from the site during the bulldozing. Costs for bulldozing can be quite high and vary considerably depending on concentration and size of materials to be removed, equipment and labor costs, etc. Table 4 gives examples of time needed to clear land using two different sizes of crawler tractors. A grower buying lands for planting can save these costs or pay more per acre if clearing is not needed.

Fig. 14: Planting site on which brush, trees and other obstacles have been removed by bulldozing.

Pre-Planting Tillage: In some instances, some type of tillage (plowing, disking, rototilling, etc.) may be desirable before trees are planted, either before the first crop of trees are established on a site or after removal of a stand and before the new rotation is begun (Fig. 15). This can help to eliminate or reduce woody and herbaceous vegetation and roots of cut trees. It can also provide a loosened soil layer, which may permit easier planting and better root development of planted seedlings. This is particularly important on finer textured soils having high clay content. In such soils, roots of seedlings may be restricted by compacted soil around the planting slit made during hand or machine planting, which makes normal root orientation difficult and causes a number of root abnormalities (see section "Tree Planting Operations"). In addition, in fine textured soils it is often difficult to close the planting slit tightly around roots of seedlings after planting. Slits often open up when soils dry out. Tillage helps to break down the compact structure of the soil, providing granular soil particles more favorable to root development and planting slit closure. Tillage can also be used to incorporate fertilizers into the soil (see section "Pre-Planting Fertilization"). Following tillage, the grower also has the opportunity to establish a more desirable ground cover-possibly a legume-on the area.

Fig. 15: Planting area being fertilized and tilled before planting seedlings.

The entire planting area can be tilled or 2- to 4-foot wide strips prepared (along the contour on sloping ground) in which trees are to be planted. To prevent formation of "clods," particularly in finer textured, high clay content soils, tillage should be done when soils are moist but not wet. Additionally, tilled areas should be allowed to settle before planting, and because of these two restrictions, late summer or fall preparation is usually preferred.

Cost of various tillage practices varies considerably depending on equipment, labor costs, terrain, type, complete vs. partial preparation, etc. Table 4 gives examples of time required to prepare land using some common combinations of tillage practice.

Chemical Control of Woody Plants: Species that root sprout (black locust, cottonwood, aspen, etc.) should probably be killed at least a year before they are to be removed from the planting site by cutting or bulldozing. Use of appropriate silvicides in conjunction with frilling (for larger trees), injectors (for medium-sized trees) or basal spraying (for smaller trees and brush) is very effective for this purpose (see Fig. 16) Foliage sprays with silvicides should also be used to kill smaller brush (see Fig. 17). If areas are mowed only and then planted, as is often done, much of the woody brush may sprout. Choice of methods and materials for control will be more limited, and total costs will increase.

Fig. 16 Scattered individual small trees on planting sites can be killed by basal spraying with herbicides prior to planting seedlings.	Fig. 17: Where brush cover is extensive on planting sites, foliage sprays with herbicides can be used to kill trees before seedlings are planted.

A number of chemicals are effective for this purpose. However, use is closely controlled by the Environmental Protection Agency, and regulations are subject to periodic change. For these reasons, specific chemicals rates and methods of application are not presented in this section. The grower is referred to recommendations that are updated periodically by personnel of the Cooperative Extension Service. In using all chemical herbicides, rates and methods of application listed on the product label must be followed closely in order to ensure safe, effective control. (For additional information on herbicides and their use, see section "Weed Control").

Control of Herbaceous Weeds at Planting Time: ^d Control of heavy grass and broadleaf weeds in Christmas tree plantations at planting time is extremely important. Initial weed control often determines whether or not trees survive and how well they grow (see Fig. 18).

d. For a detailed discussion of weed control principles and techniques, an explanation of terms and examples, see section `'Weed Control" in this manual.

Fig. 18: Seedling in dense grass sod, where survival and growth may be very poor.

Ideally, control of herbaceous weeds in Christmas tree plantations begins the fall prior to spring planting. Many growers accomplish this by spraying herbicide in 2- to 3-foot wide strips or spots in which trees will be planted the following spring. Some growers apply a foliar herbicide early in the fall when weeds are actively growing to eliminate the well established perennials. Many growers who till in the fall prior to spring planting spray areas to be tilled with a foliar herbicide a week or two before tilling. If a foliar applied herbicide is used in early fall, some additional form of weed control will be necessary to prevent re-invasion of weeds the following year. A soil applied herbicide may be applied in late fall before the soil freezes up (usually around the end of November in mid-Ohio). This will control weeds effectively during the following growing season or it may be applied in the spring about two weeks prior to planting or after one or two good rains following planting. This wait allows the soil to settle and the planting slit to close. If this is not done, the herbicide may be carried into the slit by rain and kill the tree. The heavier (finer) the soil, the greater the danger. Alternatively, other weed control techniques such as mulching or tilling may be started in the spring.

Other growers omit the foliar herbicide and use only a soil applied herbicide late in the fall. Soil applied herbicides should not be applied early in the fall because they lose much of their effectiveness in controlling weeds the following year. Mowing or tilling prior to applying these herbicides produces better and more uniform results.

Sometimes weed control in plantations cannot be started until the spring of the planting year. If it is begun early, before weeds have begun substantial growth, an application of a soil applied herbicide about two weeks before planting or after one or two rains following planting normally controls all but the most deep rooted perennials. Mulching and tilling can also be used effectively. If, however, weeds have already begun to grow vigorously, effective weed control probably will require tilling and/or application of a foliar herbicide followed by use of a soil applied herbicide, tilling or mulching.

Examples of time required for spraying using hand and mechanized equipment are presented in Table 4.

Pre-Planting Fertilization: Many fertilizers, particularly lime and phosphorus, should be plowed down and mixed into the soil before planting (Fig. 15). Such materials are somewhat insoluble, and it may take two or more years for them to become distributed throughout the rooting zone after surface application. Additionally, when large amounts of soluble fertilizers such as potassium are needed, they should be incorporated into the soil well in advance of planting, if possible. High concentrations of soluble fertilizer salts can kill or injure seedlings if they are in close proximity to roots of recently planted trees. Nitrogen fertilizers should probably not be used before planting because they are usually leached from the soil before they can provide benefits to seedlings. Pre- planting applications of fertilizers should be based on laboratory analyses of soil samples to evaluate fertility status. Soil sample "kits," including instructions and sample bags, are available from county agricultural extension agents.