Selecting Landscape Trees

Selecting landscape trees.

By Richard Flowers, ACCNP-Green Thumb Nursery-Ventura

So you want to plant a tree in your yard? Before doing so, there are many important considerations that need to be taken into account before actually doing it. How big can the tree get? What kind of look are you after? Do you want one that’s evergreen all the time or do you want one that drops its leaves during the winter? Do you want trees that produce a flower or maybe edible fruit? Many people can be overwhelmed by all the options when shopping for a tree at there favorite Green Thumb Nursery. In this article I want to provide you useful strategies for selecting a tree. The right tree in the right place.

Before you buy a tree:
Trees are a semi- permanent fixture to your landscape that can beautify your home, enhance your garden, and make you feel better. Trees can provide nice character, but however planting a tree in the wrong place, the wrong soil or a place that it does not fit, can often be very costly and could be a very big mistake. It is important to determine the size of the planting area where the tree is to be grown by simply measuring the areas length by its width. It is also critical to know how large the intended tree will get when it is fully mature. Normally when you come into our nursery the trees are small and in time the trees will become larger and wider than what you currently see. The trees will change shape, character, and size as the grow. Some trees may be fast growing, others may be slower growing, and still others may have invasive roots. You do not want to plant a tree that is too over-powering for the area or too small where it gets lost. When choosing a tree, take note if the site is near a building, fence, or other plants. You don’t wanting anything to to compete with one another. Find out how much room there is for a tree to fill in without its growth being restricted or the plants being crowded. Its is important to note If power lines are overhead, you’ll need to make sure your full-grown tree won’t touch them. Do not plant tall-growing species beneath utility lines. Utility companies prune trees that grow into overhead lines, which can severely disfigure trees and promote decay, structural failure, insect attacks, and increase utility costs. Low spreading trees are an option to be planted under overhead utility lines.

A tree growing over a home rarely causes a problem, but choosing a tree with a narrow growth habit, instead of a spreading crown may be more desirable. Consider where the tree will cast its shade. Shade is generally welcome except near planting spots, such as a vegetable garden, where you want full sun. The most valuable trees are often integral elements of outdoor living spaces. A large tree overhanging a patio encloses the space with a leafy ceiling. Some narrow growing trees along a property line creates a living privacy screen. Some trees can be messy in and around your outdoor rooms so you’ll want to avoid any varieties known for dropping a lot of twigs, leaves, fruit, or seeds.

Deciduous trees, those that shed their leaves in fall, take on a whole new look in winter. How will your tree contribute to the winter landscape? If you want privacy year-round, an evergreen tree is a better choice than a deciduous tree. If cooling summertime shade is more important, then select a deciduous tree. When researching on the type of tree you are after, it is imperative to understand what the function of the tree will be used for. Different trees serve many different functions. For example, deciduous shade trees cool homes in the summer and allow the winter sun to heat homes when they lose their leaves, while evergreens can provide a windbreak or a screen for privacy, and fruit trees or shrubs provide food for the owner or wildlife. Are you looking for shade for a patio or outdoor play space? Would you like to screen a view or create a wind block? Does your landscape need more color in spring or fall? Do you want to plant a tree that will support wildlife such as pollinators and birds? Do you want the tree to fruit? Do you want a tree that is tropical looking or more native / Mediterranean looking? Choose trees that will coexist well and feel right with you and your lifestyle.

Many trees are not conducive to being planted in a lawn area because most people incorrectly water their grass. People water their lawns shallow and more frequently. Many trees in a lawn area tend to have shallow roots that are close to the surface making the tree weaker and less stable in the soil. (shallow watering = shallow roots).These shallow roots can cause a hazard if someone trips on the surface roots. With poor anchorage in the soil form shallow roots, trees are more prone to fall over. Surface roots can also cause poor grass growth and maintenance problems with the lawn. Grass growing under a tree with dense shade often results in spotty and poor growth. Trees on the other hand, need longer, deeper watering which encourages the roots to go deeper and not ruin the lawn and jeopardize the health of the tree. If a tree must grow in a lawn, irrigate the lawn separately form the tree and select a tree compatible to lawn watering. Never allow lawn maintenance equipment to damage the trunk of a tree. Never water a mature tree at the main stem or trunk because fungus and other issues may occur, instead water where all the branches come out (the canopy or drip line).

It is important to understand that in the tree world, ornamental trees that are small, mature 20-30 feet tall and 10 to 20 feet wide. A tree for shade is considered a large tree and usually grow 30 to 60 feet or more tall and wide. Also keep sidewalks and pathways in mind, making sure you don’t create a situation where you’re always having to trim back wayward branches. Be aware of underground pipes, sewer lines, and drains that can be a limiting factor in tree selection and placement. Ideally trees should not be planted near buildings, pipes or paved areas because costly issues may occur, but if you must, small trees should be placed no closer than 10 feet from structures and no closer than 3 feet from any paved area; larger trees should be placed even farther away. Please note : Depending on the species of tree the spacing will vary.

A lot of people want to plant a tree in a city parkway where it’s surrounded by a driveway, sidewalk, the road, and /or pavement. These areas have a little cut out to plant a tree. These parkway plantings are so common but many times these areas are not the greatest because they are not hospitable for growing a tree for several reasons:

Because hot asphalt, pavement, cement in the sidewalk or a driveway this microclimate absorbs heat and could literally bake the roots if the tree is not properly watered. Also when the tree gets larger and the canopy expands, it’s very hard to water a tree properly because when you water a tree you water where all the branches and leaves come out which is known as the canopy or the drip line, that’s where all the feeder roots are and when there’s no soil (instead there is cement, asphalt or pavement) in that location you cannot water it properly. Whether your tree is in a lawn area or another another place, you do not water a mature tree close to the trunk. Oftentimes trees in such a situation may exhibit problems with shallow roots, buckling up the sidewalk or driveway or shallow roots elsewhere. These trees will be weaker and not vigorous. The tree will not will not thrive for a long period of time or it may fall down. Because roots always follow water if you water shallow the roots will be near the surface if the watering is deep the tree roots will be deeper. Trees that have deep roots can go longer in between watering therefore are more drought tolerant. Conversely, trees with shallow watering and roots require more water to be healthy because they dry out quicker. If you plant a tree that is on city property, be sure to ask the city public works or street tree department for a list of approved trees as each city has different regulations.

A note on patio trees or standards:
If you have a difficult area where many trees can and should not be planted, such as near building and walls, in tight corners, and near walkways, without the fears of branch drop or roots pushing up sidewalks then consider a standard. These standards can look very attractive when planted in the right situation. A standard is a shrub that has been grown with a central stem and all side branches removed to make a small, sturdy trunk.

This form is something that is “tree- like”, These plants have a single stem with the branches, leaves, and stems at the top, they are sometimes called a lollipop or a ball on a stick. Because these  “trees”  are not true trees with tree root systems and trunks, they will need protection from wind. These standards need to be maintained throughout their life to have the tree like appearance or else they will revert back to a shrub. Many of them will be staked their entire life.

Often over looked is how well would the intended tree do in your area? Is it hardy enough to grow in your zone? Some trees require lots of heat and dryness, while others may benefit form coastal conditions only. Some trees do not like freezing temperatures, while other don’t mind it. Take stock of the growing conditions of your planting site, especially how much light it gets, the soil type, and natural amounts of moisture. Don’t forget to include microclimates into the equation. Some trees thrive in loose, sandy soil
while others will tolerate heavier clay soil. Many trees demand all-day sun for best growth and a few flourish in dappled shade. Some trees do not like salt air, wind, and low humidity. Some trees are drought tolerant, while others like regular water.

Examine how well does your soil drain. Most trees must have excellent soil drainage. Most trees can not sit in water or grow in a mucky soil, this is a for sure death. It is recommended to perform a percolation test by simply digging a hole 1 foot deep and 1 foot wide. Fill the hole up with water. Let it drain. Fill it up again. You are determining how long it takes water to be completely drained from the hole. Ideally, the hole on the second filling should be completely drained of water in 3 – 4 hours If the soil does not do this, then you have several options to choose from, do not plant in that location, plant on a mound system or choose another tree species that will thrive in that location. Determine how much light and heat occur at that location based on climate and nearby structures, pavement, and plants; choose species suited to the right environmental conditions.

When choosing a tree for your garden be sure select the type that goes with the rest of your landscape and the style of the house. You want to have a tree that is compatible to the rest of the plants in your landscape (cultural requirements) i.e. same water requirements, soil, care, and fertilizer. Examine the space available for growth and learnabout the mature size of candidate plants. Give limbs and roots plenty of room to grow and use only plants that will fit at maturity.

With all that being said, the best advice that I suggest if you have no idea what kind of tree to plant in your landscape is to drive or walk around your neighborhood, park, botanical garden, cemetery, shopping mall or other areas with an urban forest and look at the trees that have been there many years. Examine them as to the form and shape you want. View them at different times of the year so you have an idea of how they preform and look during certain times. See how they behave and grow. If you are interested in particular tree and do not know the name of it, take good quality photos or a sample to your favorite Green Thumb Nursery and we can identify the name of the tree. If you have any questions about a particular tree we will gladly assist you. Please be advised, if the tree is on private property and to be courteous you may need to askfor permission to take a sample or take a picture of the tree.

Selecting a tree:
Once you finally decide on the type of tree you want to buy, you want to select them based on certain criteria.

Choose a tree that has:

  • A straight trunk with well-spaced branches. Branches should have good helical distribution.
  • A trunk free of wounds or damage. If they do and the tree looks otherwise healthy and
    vigorously growing it may heal itself.
  • Roots growing straight out from the trunk.
  • A good form and structure
  • No or limited, crushed girdled twisted, or circling roots in the container.

Inspect the tree carefully to identify problems related to form, injuries, or roots. When inspecting a tree you want to buy, remove the root ball from the container and pay special attention to larger, exposed roots. Circling roots that may girdle and kill other roots or the entire tree if wrapped around the trunk. Fine circling roots may be cut away at planting. Larger roots may be straightened if still flexible. You should be able to see the basal trunk flare with container-grown plants.

You do not want multiple stems originating from the same point and branches grow into each other unless the tree is specifically pruned and grown that way or the species naturally grows that way. Sometimes these occurrences can be removed by good quality pruners and proper technique.

You do not want a tree planted in an undersized ball or container. I hope you find this information helpful. If you have any questions, head down to your favorite Green Thumb Nursery we will be happy to assist you in your plant endeavors.

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