SITE PLANNING AND TREE
FOR THE NEW HOME
F. J. Regulski, Jr.
Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences
University of Florida / John T. Woeste, Dean
Cover: Scale drawing of a typical root system of a 4" caliper
tree. Note the proportion of roots extending beyond
the drip line.
Site Planning and Tree Protection for the New Home
F. J. Regulski, Jr.1
Much of the value of a home can be attributed to its location or
setting. Homes with views of lakes, beaches, rivers, or other natural
environments have long been prized as being more valuable than
similar homes located on less distinctive land. The value of a home
can also be greatly affected by the trees which surround it. A tree
which takes 20 or more years to reach maturity can be considered an
irreplaceable asset to a home since the average homeowner lives in a
home for just 3 years. The International Society of Arboriculture
has established standards which estimate the value of a tree on
criteria such as size, species, condition, and location. The trees on a
site not only add value to a home but also provide shade to reduce
summer cooling costs and block winter winds to reduce heat loss.
Information in this publication can guide present and prospective
homeowners in the use of precautions and procedures when devel-
oping land for a homesite.
Requirements for Healthy Trees
Trees have certain requirements for maintaining normal healthy
growth and development. Trees absorb water, minerals, and oxy-
gen from the surrounding soil through their roots. To do this effi-
ciently, water and oxygen must be in proper balance in the soil. This
balance is also important to the many beneficial organisms and
microorganisms which inhabit the soil around a tree's roots. If this
balance is disrupted, accumulations of noxious gases and chemicals
will occur and might depress normal plant growth. The soil most
important to a tree's root growth encompasses an area equal to the
spread of its branches (drip line) and 18 inches in depth. However,
many species of trees, especially forest trees, have most of their
feeder roots in the upper 6 to 8 inches. These trees are very sensitive
Assistant Professor, ARC-Monticello, Institute of Food and Agricultural Sciences
(IFAS), University of Florida.
to soil disturbances. Any injury to the roots also greatly reduces
water and oxygen absorption by the roots.
Not only healthy roots but also a healthy trunk is important to
plant growth. Roots absorb water and minerals that are trans-
ported up the trunk, through the branches, and into the leaves. In
the leaves, photosynthesis occurs utilizing light, water, and carbon
dioxide to produce various sugars which are again transported to
other parts of the tree, including the roots. Most transport occurs
just below the bark; therefore, wounds to the trunk or roots can
interrupt the flow of these essential products. These wounds also
permit insects and disease organisms to enter a tree more readily
thus accelerating death or decay. It is important to understand how
a tree functions and how changes that we make on or around the tree
can affect its survival and growth for either better or worse.
Many homes are being built in naturally wooded areas. These
wooded areas are sensitive to any disruption of the soil-plant envir-
onment. Trees in a forest habitat have developed under a stable set
of environmental conditions such as light intensity, wind protection,
soil aeration, and moisture and root zone temperatures. The prim-
ary rule in building on these sites is to minimize site disturbances
and where these are unavoidable to take certain precautions before
An evaluation of tree species is the first step in development of a
site plan for a home in a wooded area. An evaluation should include
an inventory of the trees. This can suggest the impact of construc-
tion upon the site. If you are evaluating a potential site or are
actually beginning development of the site for construction, these
steps can be helpful:
1. Evaluate Tree Species. The identity of the trees present is
important because some species have certain characteristics
that can be either a problem or a benefit to a homeowner,
depending upon how the trees are used. Tree species differ in
longevity, disease and insect resistance, color, shape, growth
rate, root development, tolerance to stress, and mature size,
as well as other characteristics. The county forester or exten-
sion agent can provide you with a list of preferred trees for
your area of Florida.
2. Inspect Trees for Health and Vigor. Inspect trees for the
presence of large dead branches, fallen limbs near the tree,
fungi on or near the trunk, oozing of fluids, or loss of bark.
Also compare the trees within a species for leaf color and
amount of yearly twig growth. These factors may indicate a
tree in poor condition that should be removed before con-
struction. Large trees or old trees do not withstand very well
changes in their environment. Major construction should be
avoided near these specimens, for a distance of at least ten
feet from the trunk although the entire drip line should be
avoided when possible. Smaller, younger trees may have a
greater potential for survival when construction is near.
3. Make a Scale Drawing of Site. With the previous informa-
tion in mind, make a scale drawing of the site:
1. Locate major trees selected for preservation.
2. Locate also a number of possible areas available for final
location of the house. The decision on the final location
may take advantage of existing trees that provide shade
patterns, screening, or framing for the building.
3. Minimize site disruption. This can be done by grouping
trees into naturalized areas which will remain undis-
turbed. The size of the areas varies with lot size. This
approach minimizes risk of tree stress and increases the
chances of a tree's survival. This concept also reduces
maintenance of the landscape after construction, by leav-
ing a natural mulch (leaf litter) to reduce weed growth.
Groupings should be identified on the scale drawing.
4. Determine access roads. Identify them on the scale draw-
ing. After this final part of the drawing has been completed
all map features are ready to be transferred to the actual
4. Transfer to Actual Site. The house foundation can be staked
out and the roads and walks can be marked off with flagged
rope to limit construction traffic to certain areas. Trees for
removal should be clearly marked with paint both on the
stump and chest high. Individual trees and natural areas
which are to be saved should now have protective barriers
erected at the edge of their drip lines. These barriers can be 2
x 4 inch lumber or flag rope and stakes, just as long as they
are easily visible (Figure 1.). At this time the builder should
be shown the site and told which trees are to be saved. Any
problems of construction logistics should be cleared up at this
time, not after the job has begun.
Types of Tree Damage and How to
Avoid or Remedy Them
Construction damage to trees can be categorized by location -
above or below ground. The more difficult to correct and more
harmful to the tree are the below-ground damages. Much of this
damage can be avoided by careful site planning and fencing (rop-
ing) off areas around trees or group of trees.
Compaction. Soil compaction is caused by repeated traffic over
the root zone of trees by heavy construction equipment and
vehicles or storage of materials. Compaction reduces aeration of
the soil around roots and is difficult to remedy. It is best to keep
traffic off the roots by fencing (roping) the drip line area of the
single tree or the group (Figure 1.).
Soil Fills. The upgrading or raising of the original soil level can
be extremely harmful to established trees because of the
reduced oxygen in the root zone. The depth of fill that a tree can
tolerate depends on the species, vigor, percent of root burial, and
depth and kind of fill. Maples, some oaks, dogwoods, pines,
beech, and other shallow rooted species respond poorly to even as
little as 2 inches of fill. A sandy fill has much greater aeration
and is more desirable than a heavy clay fill.
If a deep filling is necessary, a tree can be saved by building
around the tree a dry well large enough to accommodate future
tree growth and slightly higher than the final fill grade (Figure
2.). Place around the dry well lengths of perforated plastic drain
pipe that radiate to an outer circle of perforated pipe located just
beyond the drip line of the tree. Place vertical pipe on the outer
circle and extend it to the fill grade. Then fill the area in and
around this circle of pipe with coarse stone and place smaller
stone on top. Place straw or woven fiberglass last, to prevent the
fill soil from settling between the stone and blocking aeration.
Use a sandy loam as fill, not construction trash.
Lowering Grades. Lowering a grade removes soil from around
a tree's roots and is a serious threat to a tree's survival because
most feeder roots are within 6 to 8 inches of the surface. This
procedure damages roots by severing and exposing them to the
drying effects of air. This situation should be avoided by site
planning, but if necessary the use of earth terraces or retaining
walls placed to include the drip line should help to minimize the
Drip Line -
Single Tree Natural Area (group)
Figure 1. Protective Barrier Placement at Drip Line.
Sripe -- Top View
ll Tree Trunk
e Small Stone
ip L Dry Wall
horizontal Pipe Vi
Figure 2. Construction of a Dry Well Aeration System.
of Fill Grade
soil-tree disruption (Figure 3.). Disturbed roots should be buried
immediately with a backfill mixture of peat moss and a sandy
loam soil. If a part of the root system is lost, an equal percentage
reduction in branch growth should be made to maintain the
water balance between the roots and the top of the tree. This
pruning should be done immediately.
Trenching. Trenching for underground pipes and cable can
seriously damage a tree by severing many roots thereby disturb-
ing the water balance of the tree. The damage of trenching can
be reduced by digging trenches directly toward a tree (Figure
4.), but then, near the trunk, tunneling just to the side of the tap
root at the same depth as the trench. This method reduces root
cutting and resulting tree stress.
Drainage Change. Changes in the patterns of both surface and
sub-surface drainage occur during and after construction.
Parking lots, patios, cement walks, roads, and walls tend to
increase runoff and also block the natural surface drainage
patterns causing puddling. Trees near these structures could be
subjected to flooding stress by excess water in the soil over a
period of time. Certain species are sensitive to wet feet while
others are quite tolerant. The puddled areas can be drained with
drainage pipe or be graded so that water can drain.
Wounds. A wound is a break in the bark, exposing the tree's
inner tissue to the air. These are more obvious than the below-
ground injuries and are generally less serious because they can
be readily repaired.
Trunk and bark wounds can be caused by collisions with heavy
equipment, careless use of hand tools or mowers, fire, storm
breakage, lightning, and animals. All of these injuries reduce
the flow of water and nutrients in the tree and provide major
locations for entry of disease-causing organisms and insects.
Protective barriers or fencing should be used to separate trees
from the hazard, and care in avoiding damages will greatly
reduce this type of injury.
If trees are wounded, steps should be taken immediately to
exclude disease organisms and insects and to speed healing of
1. Use a sharp knife to remove the dead or injured bark, a little
at a time until uninjured inner bark is reached. The wound
Figure 3. Cross Section of Earth Terrace and Retaining Wall.
- -----Original Grade
Poor Contour Line
for Soil Removal
referred Contour Line
of Soil Removal
Figure 4. Method of Properly Burying Cable.
should be cut to form a vertical ellipse; however, keep it as
small as possible.
2. An application of a nonpetroleum-base wound dressing can
be applied for aesthetic reasons; however, this does not
encourage healing of the wound.
3. To increase tree vigor, remove dying branches. The tree can
also be fertilized and watered. Remove dead and fallen
branches from the area so that they cannot harbor harmful
insects and disease organisms.
Leaf Litter Removal. Leaf litter retains soil moisture and also
reduces the temperature fluctuations of the root zone, the upper
6 to 8 inches. Unmulched soils can reach temperatures exceed-
ing 165 F which is lethal to roots. Even temperatures of 950 F
retard root growth of some species. Leave as much natural leaf
litter as possible and cover bare areas with some sort of mulch
such as straw, until a natural mulch is re-formed.
Cleanup. After construction is completed all debris should be
hauled away, not burned or buried on the site. Some building
materials are toxic to plants or can change the soil pH. All final
grading around trees should be done by hand, not with heavy
equipment. Finally, the protective barrier fences can be removed
After everything else is completed.
Some of the site planning, tree selection, protection, remedial
construction, and maintenance can be done by the homeowner with
the aid of the county extension agent or forester. However if valua-
ble trees, difficult locations, or extensive site modifications are
involved, the services of a qualified tree surgeon or arborist should
be obtained. These specialists possess the proper skills, techniques,
and tools to maximize the survival of trees. Remember that trees
take a long time to grow but damage takes only a moment and much
of it can be prevented.
Black, R. J. Landscaping to conserve energy. EI-17. Fla. Coop. Ext. Ser-
vice, IFAS, University of Florida. 1980.
Black, R. J., and Hamilton, D. F. Native plants for Florida landscapes.
OH-25. Fla. Coop. Ext. Service, IFAS, University of Florida. 1982.
Black, R. J., and Midcap, J. Ornamental trees for south Florida. OH-22.
Fla. Coop. Ext. Service, IFAS, University of Florida. 1980.
---. Ornamental trees for central Florida. OH-28. Fla. Coop. Ext. Ser-
vice, IFAS, University of Florida. 1980.
---. Ornamental trees for north Florida. OH-29. Fla. Coop. Ext. Service,
IFAS, University of Florida. 1980.
---. Pruning ornamental trees and shrubs. OH-35. Fla. Coop. Ext.
Service, IFAS, University of Florida. 1981.
Flinchum, J. A guide to selecting existing vegetation for low-energy land-
scapes. Circular 489. Fla. Coop. Ext. Service, IFAS, University of Florida.
Tree protection manual for builders and developers. Fla. Div. of Forestry.
This public document was promulgated at a cost of $932.76, or
19.4 cents per copy, to provide information on site planning and
tree protection for the new home. 02-4790-84
COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORI-
DA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, K. R.
Tefertlller, director, In cooperation with the United States Department F
of Agriculture, publishes this Information to further the purpose of the
May 8 and June 30, 1914 Acts of Congress; and is authorized to pro-
vide research, educational information and other services only to Indi-
viduals and institutions that function without regard to race, color, sex or national ori-
gin. Single copies of Extension publications (excluding 4-H and Youth publications) are
available free to Florida residents from County Extension Offices. Information on bulk
rates or copies fdr out-of-state purchasers Is available from C. M. Hinton, Publications
Distribution Center, IFAS Building 664, University of Florida, Galnesville, Florida
32611. Before publicizing this publication, editors should contact this address to deter-