The Tree Canopy
By Harbor Light News Staff | on August 23, 2023
© Patrick Wise
Residents of Harbor Springs, let’s keep the trees in our city healthy! In previous issues of The Tree Canopy, we have looked at the benefits of trees. This month we will look at threats to trees in our urban forest and what we can do to help.
What is meant by threats to trees?
The urban environment takes a toll on trees, creating stress and making them more susceptible to disease, attack by pests, decline and even death. Compacted soils, artificial surfaces that do not absorb water, summer heat, physical damage to bark, limbs and roots are all examples of stresses.
Some of the threats that are out of our control.
Climate. Climate has always created stress on trees. Periods of drought, flooding, temperature extremes and high wind events are prime examples. Trees that are native to our area are adapted to these conditions.
How can we help? When planting new trees, we can select the Right Tree for the Right Place so it has the very best chance of not only surviving our cold winters but thriving.
Emerald Ash Borer (Adobe Stock)
Disease and insects. We’ve seen first-hand in northern Michigan, the devastation caused by disease and insects in our native tree populations. Examples include American Elm (Dutch Elm Disease), White Ash and Green Ash (Emerald Ash Borer) and Paper Birch (Bronze Birch Borer). This illustrates that even native trees are not immune.
How can we help? We can help by being vigilant and treating these problems when they occur in existing trees. When planting new trees, we can select the Right Tree for the Right Place, species that have few known problems or newer cultivars (varieties) that are resistant such as ’Princeton Elm’ and the ‘White Spire’ Birch.
Wildlife – A final example of a natural threat to trees is experienced by many of us, specifically deer and rabbits.
Woodpecker damage (Adobe Stock)
How can we help? Again, the best solution is to select the Right Tree for the Right Place using trees that are resistant to deer browsing. Where browsing is evident, we can use deterrents, such as Liquid Fence or Deer Scram or one of many other home solutions that you can find online, such as Irish Spring soap shavings or marigolds.
Some threats we can control.
Use of monoculture plantings (overuse of particular species). Communities that were most devastated by the loss of elms, ash and birch were those with a high percentage of those species.
How can we help? The Harbor Springs Tree Board and staff have a best practice of focusing on diversity in new plantings so that an infestation of one species won’t devastate the city’s urban forest.
Establishment of invasive species. Certain native and nonnative trees can upset the ecology in a forest when introduced.
How can we help? Fortunately, most invasive species are not available commercially, with one major exception, the Norway maple, which is still used extensively in the nursery trade. The Harbor Springs Tree Board and staff have proactively chosen to leave this tree off Right Tree Right Place list.
Poor planting practices. Improper planting practices create early stress on a new tree, affecting its health and ability to reach its potential.
What we can do to help? We can help by ensuring that good planting practices are followed including…• Top of the root ball should be at natural grade (not too high, too low)• Ropes and burlap should be cut from the top of the root ball• A small circle of mulch around the tree will protect from damage due to mowers or string trimmers damage. Excess mulch over the root ball) should be avoided.• Once planted, the tree should be thoroughly watered and adequate water provided for the first year or two
On-going tree care. The first two years in the life of a newly planted tree are the most important in insuring its health. During that period the plant is ‘establishing’ (developing a root system beyond the confines of its root ball).
What can we do to help?• Supplemental water should be provided as needed.• Pruning should be done properly and conservatively.• For established trees and new trees, it’s important to protect the tree from mechanical damage from mowers and string trimmers, construction equipment and other damage to the bark.
As you’ve seen, the best thing we can do to help our urban forest is to plant the Right Trees in the first place. The Tree Board and staff have developed Right Tree Right Place, a list of trees suitable for use in Harbor Springs. The trees on the list have been vetted for hardiness for our cold winters and resistance to
disease and pests. The needs and attributes of the trees have been identified for the user, including, height, moisture requirements, light requirements and resistance to road salt to deer browsing. This list is available online or at the City by calling Victor Sinadinoski at (231) 526-2104.
It was President Franklin Roosevelt who said forests are the lungs of our land, purifying the air and giving fresh strength to our people. This still rings true today, let’s choose the Right Tree for the Right Place!