Tree selection is one of the most important investment
decisions a home owner makes when landscaping a new home or
replacing a tree lost to damage or disease. Considering that
most trees have the potential to outlive the people who plant
them, the impact of this decision is one that can influence a
lifetime. Match the tree to the site, and both lives will
The question most frequently asked of tree care professionals is
“Which kind of tree do you think I should plant?” Before this
question can be answered, a number of factors need to be
considered. Think about the following questions:
- Why is the tree being planted? Do you want the tree to provide
shade, fruit, or seasonal colour, or act as a windbreak or
screen? Maybe more than one reason?
- What is the size and location of the planting site? Does the
space lend itself to a large, medium, or small tree? Are there
overhead or belowground wires or utilities in the vicinity? Do
you need to consider clearance for pathways, patios, or
driveways? Are there other trees in the area?
- Which type of soil conditions exist? Is the soil deep, fertile,
and well drained, or is it shallow, compacted, and infertile?
- Which type of maintenance are you willing to provide? Do you
have time to water, fertilize, and prune the newly planted tree
until it is established, or will you be relying on your garden
or tree service for assistance?
Asking and answering these and other questions before selecting
a tree will help you choose the “right tree for the right
Trees make our surroundings more pleasant. Properly placed and
cared for, trees increase the value of your property. A large
shade tree provides relief from summer’s heat and, when properly
placed, can reduce summer cooling costs. An ornamental tree
provides beautiful flowers, leaves, bark, or fruit. Evergreens
with dense, persistent leaves can be used to provide a windbreak
or a screen for privacy. A tree that drops its leaves in the
autumn allows the sun to warm a house in the winter. A tree or
shrub that produces fruit can provide food for the owner and/or
attract birds and wildlife into your home landscape. Street
trees decrease the glare from passing traffic, reduce runoff,
filter out pollutants, and add oxygen to the air we breath.
Street trees also improve the overall appearance and quality of
life in a city or neighbourhood.
Form and Size
Frank Lloyd Wright, the famous architect, once made the comment,
“form follows function.” This is a good rule to remember when
selecting a tree. Selecting the right form (shape) to complement
the desired function (what you want the tree to do) can
significantly reduce maintenance costs and increase the tree’s
value in the landscape. When making a selection about form, also
consider mature tree size. Trees grow in a variety of sizes and
shapes, as shown below. They can vary in height from several
inches to several hundred feet. Select a form and size that will
fit the planting space provided.
Depending on your site restrictions, you can choose from among
hundreds of combinations of form and size. You may choose a
small-spreading tree in a location with overhead utility lines.
You may select a narrow, columnar form to provide a screen
between two buildings. You may choose large, vase-shaped trees
to create an arbor over a driveway or city street. You may even
determine that the site just does not have enough space for a
tree of any kind.
Selecting a tree that will thrive in a given set of site
conditions is the key to long-term tree survival. The following
is a list of the major site conditions to consider before
selecting a tree for planting:
- soil conditions
- exposure (sun and wind)
- human activity
- space constraints
- hardiness zone
The amount and quality of soil present in your garden can limit
planting success. In urban sites, the topsoil often has been
disturbed and frequently is shallow, compacted, and subject to
drought. Under these conditions, trees are continuously under
stress. For species that are not able to handle these types of
conditions, proper maintenance designed to reduce stress is
necessary to ensure adequate growth and survival. Many garden centres stock special
soil sampling kits which test for
fertility and pH (alkalinity or acidity). The tests
can be used to determine the best method to improve poor
soil conditions with fertilizers or soil amendments (sand, peat
moss, or manure) and will also help us recommend tree species that will do well in the soils
found on your site.
The amount of sunlight available will affect tree and shrub
species selection for a particular location. Most woody plants
require full sunlight for proper growth and flower bloom. Some
do well in light shade, but few tree species perform well in
dense shade. Exposure to wind is also a consideration. Wind can
dry out soils, causing drought conditions and damage to branches
and leaves during storms, and can actually uproot newly planted
trees that have not had an opportunity to establish root
systems. Special maintenance, such as staking or more frequent
watering, may be needed to establish young trees on windy sites.
This aspect of tree selection is often overlooked. The reality
of the situation is that the top five causes of tree death are
the result of things people do: soil compaction, underwatering,
overwatering, vandalism, and the number one cause—planting the
wrong tree—account for more tree deaths than all insect and
disease-related tree deaths combined.
Tree roots require oxygen to develop and thrive. Poor drainage
can remove the oxygen available to the roots from the soil and
kill the tree. Before planting, dig some test holes 12 inches
wide by 12 inches deep in the areas you are considering planting
trees. Fill the holes with water and time how long it takes for
the water to drain away. If it takes more than 6 hours, you may
have a drainage problem. If so, ask check with us for
recommendations on how to correct the problem, or choose a
Many different factors can limit the planting space available to
the tree: overhead or underground utilities, pavement,
buildings, other trees, visibility. The list goes on and on.
Make sure there is adequate room for the tree you select to grow
to maturity, both above and below ground.
Hardiness is the plant’s ability to survive in the extreme
temperatures of the particular geographic region in which you
are planting the tree. Plants can be cold hardy, heat tolerant,
or both. Most plant reference books provide a map of hardiness
zone ranges. Check with your local garden center for the
hardiness information for your region. Before you make your
final decision, make sure the plant you have selected is “hardy”
in your area.
Insect and disease organisms affect almost every tree and shrub
species. Every plant has its particular pest problems, and the
severity varies geographically. These pests may or may not be
life threatening to the plant. You should select plants
resistant to pest problems for your area. We can advise
you on information relevant to problem species for your
Personal preferences play a major role in the selection process.
Now that your homework is done, you are ready to select a
species for the planting site you have chosen. Make sure you use
the information you have gathered about your site conditions,
and balance it with the aesthetic decisions you make related to
your personal preferences.
The species must be suitable for the geographic region (hardy),
tolerant to the moisture and drainage conditions of your soil,
be resistant to pests in your area, and have the right form and
size for the site and function you have envisioned.
Remember, the beautiful picture of a tree you looked at in a
magazine or book was taken of a specimen that is growing
vigorously because it was planted in the right place. If your
site conditions tell you the species you selected will not do
well under those conditions, do not be disappointed when the
tree does not perform in the same way.
If you are having difficulty answering any of these questions on
your own, contact us; It is better to get a professional involved early
and help you make the right decision than to call them
later to ask if you made the wrong decision.