KENTUCKY CHRISTMAS TREE PRODUCTION WORKBOOK:
SITE PREPARATION
ISSUED: 4-86
REVISED: 8-91
Bonnie L. Appleton; Deborah B. Hill
Site preparation, whether for first
time planting of Christmas trees or for replanting after harvesting, should
be done well before the actual planting time. The extent to which the site
must be prepared depends on many factors including existing vegetation,
site topography, available equipment and labor, cost, time of year and
how the site will be maintained.
The many reasons for preparing a site
include:
•to remove or reduce competition from
existing vegetation, thus increasing seedling survival and tree quality,
•to facilitate laying out the planting
design,
•to make planting and general maintenance
easier,
•to increase access for labor, equipment
and, ultimately, customers,
•to reduce disease and insect problems.
Rarely is non-intensive or zero site preparation appropriate. Intensive
site preparation is especially indicated where fescue is the existing ground
cover on the proposed plantation site. Generally one or more of the following
will be necessary to ready a site for planting: clearing, cultivating,
mowing, and/or chemical application.
Clearing
Where brush, trees, rocks, fencing
or other major obstacles exist, these items should be cleared off prior
to planting. Brush and trees can be cut and chemically treated to inhibit
resprouting, or they can be pulled or pushed aside with equipment.
Bulldozers, front-end loaders and trackers
can be used for clearing but care must be used to reduce soil compaction
and to avoid stripping off topsoil. In many cases this work must be contracted
out, so cost will be an important consideration. Occasionally animals (sheep,
goats) and burning are also used for clearing.
Cultivation
Cultivation may be necessary after
a site is cleared, or may be adequate alone where heavy vegetation does
not exist. An entire area may be plowed and disked, and a new cover sown,
or individual planting strips may be prepared. If an area is sloped, contour
plowing will be necessary.
Soil should not be worked when it is
wet, so depending on planting time (fall vs. spring), cultivating should
be done from at least one month to several months in advance. Air pockets
in the soil must be allowed to settle so that roots will not dry out.
Cultivation is more important with
heavy clay soils than with sandy or loamy soils to make planting easier,
to increase root penetration and to keep slits from opening up in the ground
when the soil is dry. Clay soils may also benefit from subsoiling (6-12
in. deep) to break up a deeper barrier which can inhibit water percolation.
When you cultivate, you can also incorporate fertilizers if a soil test
indicates that you need them.
Mowing
If an old field is the planting site,
mowing may be all that is necessary, either the fall before spring planting
or immediately before planting. While mowing is the least expensive method
of site preparation, it may be the least effective if more extensive preparation
is needed.
Applying Chemicals
An increasingly popular method of site
preparation involves applying chemicals, alone or combined with mowing.
A contact herbicide such as Roundup* can be sprayed in spots or bands for
hand planting, or in bands or strips for machine planting. For spring planting
it is often preferable to apply the herbicide the previous fall.
Spot spraying can also serve to mark
where individual trees should be planted. Broadcasting a herbicide for
total vegetation kill is not recommended unless a new cover will be planted.
Be sure to read all herbicide labels thoroughly and follow all instructions
carefully.
Replanting
Where a site is being prepared for
replanting, the extent of preparation will depend on whether the area has
been partially and irregularly harvested (not full rows) or clear cut.
Clear cutting makes site preparation easier but may mean some trees must
be cut prematurely for the full tree market. See FOR-29 for marketing ideas
for smaller trees.
Many growers leave old stumps as opposed
to pulling them. Where old stumps are left, they should be treated with
an insecticide (such as lindane*) so that the Pales weevil insect, which
infests old stumps, will not feed on new seedlings. Waiting 9 months to
a year before replanting near old stumps can also help reduce pest problems
for new seedlings. Many growers leave cut fields for at least a year before
replanting. Each rotation will deplete the fertility of the soil to some
degree. Retest the soil before replanting to see if fertilization or a
particular soil amendment is needed.
*Reference to a herbicide or insecticide, either by trade or common
name in no way represents a recommendation or endorsement of that chemical.