TM 5-803-13/AFM 126-8
is of prime importance. Limiting the extent of clearing
riprapped or planted with ground cover or other low
and grading operations protects the environment and
maintenance plants which do not require mowing.
lowers construction costs.
Extensive grading should be avoided near existing trees;
b. Fast-growing trees regarded as weed types may
addition of deep fill or compaction of the soil within the
comprise the predominant native vegetation in certain
drip-line can eventually kill the tree. Each site should be
areas. Such trees are sometimes worthy of preservation
studied carefully to minimize grading and take maximum
until new ornamental plantings have matured, at which
advantage of existing topography, vegetation and topsoil.
c. Detail planting. Flower beds and sheared hedges
time the weed trees can be removed.
c. During site construction, minor variations in road
require a great deal of costly maintenance and should be
and walk layout should be made to avoid damage to
used sparingly in selected locations. Where flower beds
important vegetation.
and sheared hedges are appropriate restraint in design can
minimize maintenance.
2-16. Maintenance. Maintenance and its resultant
2-17. Plant selection. Trees, shrubs, ground covers,
costs may be kept to a minimum by coordinated planning.
The design factors described below are essential for
vines and turf make up the palette used in planting com-
economical grounds maintenance and should be con-
positions (fig 2-24). Selected varieties should be as few
sidered in the early design stages of a project.
as necessary to satisfy the requirements and objectives of
the design. By limiting varieties, clashing colors and
is necessary for successful plant growth and erosion
forms are less likely to occur, and a unified composition
control. Subsurface drains should be installed to correct
can be created. In selecting plants for a specific project,
conditions of excessive water retention in the soil. An
growth characteristics must be considered. These
alternative to subsurface drains, in some cases, is the
characteristics are documented in landscape architecture
selection of plants tolerant of wet conditions. Surface
literature, available through libraries, and government
drainage in planted areas will be aided by proper grading.
publications. Only those plants which can thrive with low
TM 5-820-4/AFM 88-5, Chap 4 contains further
maintenance under actual site conditions and produce the
information concerning drainage.
desired effect should be chosen. An investigation of
b. Grading. Steep slopes are difficult and expensive to
plants growing at the project site and also at the oldest
mow and maintain and are subject to erosion. Good
parks and cemeteries in the same general vicinity will
grading design can often reduce the steepness of slopes.
suggest plants that may be used with confidence; plants
Slopes which must be mown should not exceed a grade of
found thriving under adverse conditions are likely to
3:1; top and bottom should be rounded to prevent erosion
succeed with minimal maintenance. The ecological
and facilitate mowing. Slopes steeper than 3:1 should be
association of plants is an additional factor in plant
2-18
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