Tree Maintenance

Quick Links:
Planting |  Pruning |  Removal |  Hybrid Poplar Removal |  Dutch Elm Disease |  Black Knot

St. Albert residents take pride in the community's many green spaces and abundance of trees. The Public Works Department works to ensure the community's parks and recreational areas are at their finest.

The City’s Tree Services Crews operate several programs including the following tasks:

Planting

The City of St. Albert replaces trees removed on boulevards during the year the following summer budget permitting. Public Works will review areas that require replacement and trees are ordered from various tree nurseries in the area.

 

Responsibilities:

  • Planting and maintaining replacement trees along residential boulevards, buffers and parks.

  • Development of nursery stock to good standards of health, structure and hardiness

    Homeowners are encou    raged to water new trees that are planted to help ensure survival.

Pruning

Public Works prunes City trees mostly through out the summer months, usually on younger trees. This gives a good training area and helps to provide the trees a healthy start for the next season as well as gives them good form to grow.  Generally, lifting of boulevard trees is performed versus structural pruning.

Responsibilities:

  • Pruning trees to ensure roadway and traffic sight lines are clear and traffic signs and signals are plainly visible.  This program visits all areas of the City twice a year to ensure that traffic signals and signs are unobstructed.
  • Lifting involves pruning to ensure that low branches are high enough to avoid interfering with vehicle and pedestrian traffic on roads and sidewalks. This is a major project and crews attempt to keep to a cyclic program of lifting through all City roadways and residential areas.
  • Sanitation pruning is the removal of dead and diseased wood to stop or slow the spread of disease.

  • Structural pruning entails the removal of competing leaders, badly joined branches, and various unsound growth habits.  This ensures that the tree can develop in a strong, healthy and tall form. In this area, crews mainly work with younger trees, where the most benefit is gained from the time spent.

Removal

One of the main priorities for tree removal within the City is to ensure that safety of our residents and property is met.  Those trees that are dead and/or dying and that could potential hurt or injure people and/or adjacent properties are inspected and removed.  Those trees that are taken out will be placed on the list for replacement for the following summer.

Responsibilities:

  • Pruning or removing trees that present risk or liability to the public.
  • Removing badly broken, dead or dying trees, including those in natural areas that may pose a risk to people or adjacent private properties.

Natural Areas

  • Natural areas are dealt with if they are determined to be a safety or fire hazard.  In these areas, rotting logs and general forest litter do help with retaining moisture and helps to retard fire.

Reporting Damaged, Broken or Diseased Trees

If you would like to report a tree that needs to be trimmed or if it is damaged, broken, or diseased please contact Public Works at 780-459-1557.  These requests are recorded and sent to the appropriate section.  They will then be inspected and scheduled for repair based on their level of severity.

Hybrid Poplar Removal Program

In recent years, concerns have been raised with the Hybridized Poplar trees that were planted by developers on City properties adjacent to private lands.  The past planting of this type of tree in St. Albert has created unforeseen hazards and liabilities tot adjacent properties and infrastructure.  Poplar trees are also relatively poor in structure, with heavy branches, multiple weakly joined stems, a relatively low strength to weight ratio and a fairly short life cycle.  The fast growing nature of these trees produces massive trees with weak wood.  The extensive surface root system creates trip hazards and will sprout trees upon injury.  As some of the most massive of the locally grown species with a mature height of 20 to 25 meters and a useful life expectancy of 15 to 30 years (Alberta Agriculture), hybridized poplars require a high level of maintenance and often removal.  Recent drought and pollution has caused the dieback of the tops of many of these trees.  Also, insects and disease, particularly cankers, have also contributed to the shortened life span.

       

To address these concerns Public Works has scheduled the removal and replacement of the Hybrid Poplars that are adjacent to residential properties and vulnerable infrastructure such as asphalt trails and sports fields.

At present, the City of St. Albert's program has been established as follows:

  • In the spring, poplars that are in close proximity to private lands and vulnerable infrastructure are assessed, and a list of trees for removal is created.
  • The trees to be removed are injected in the fall with herbicide.  This will minimize the regrowth from remaining roots.
  • In the fall, after some of the summer programs are completed, the takedown of the listed trees is executed.

  • In the following summer, after the stump killing treatment is completed, the stumps are removed and new trees are planted.

Examples of damaged or dangerous hybrid poplars:

 
Picture 1:
Picture 1 shows an interior cavity
of a hybrid poplar.  The continuous
crack indicates a structural flaw
that has potential for failure in the
future.		 Picture 2:
Picture 2 shows a cross section that will eventually result in the tree splitting in two.

The current plan for replanting those poplars that were removed this past fall and winter is scheduled for 2012.

Bronze Leaf Disease on Poplars

In the fall, poplar trees through out the City can be come infected with Bronze Leaf Disease.  Residents can check their poplars for the following symptoms:

  • Leaf turns orange-brown to reddish-brown, starting from the edges and moving inward towards the base of the leaf.
  • Leaf veins remain a bright green colour.
  • Infected leaves can remain attached to the tree over winter.

To remove infected branches pruning four to six inches below the infection will be necessary.  Residents should dispose of the diseased branches at the Compost Depot, where this material will be incinerated. 

Dutch Elm Disease

In recent decades, Dutch Elm disease has made its way across Europe, and was eventually introduced into the Elm populations in Eastern North America.

Despite the efforts of many pest control personnel and arborists, a large percentage of the American Elm population has been destroyed by this disease. In the last few years, the progress of the disease across North America has been slow, but unchecked. The disease is now found in all parts of this continent except in Alberta and BC.

Prevention

The Alberta 'Stop Dutch Elm Disease' Society (StopDED) has been formed to promote awareness of Dutch Elm disease and other critical pests of landscape trees.  They coordinate monitoring of insects that may carry the disease or cause it to spread; as well as maintain the provincial response plan for DED infection.  St. Albert has been an active member of the Society and its goals.  For more information on the Society and their work please visit www.stopded.org.

Pruning Practices and Guidelines

Elms should be pruned to remove any dead wood, which would attract the beetles to the tree.  Elm bark beetles and Red Elm Weevils spend part of their larval life cycle in the cambium (inner bark) of the elm trees then emerge to feed and mate in other trees.  This movement between trees is one of the main causes of the spread of DED.  Logs and branches of Elms should not be stored or moved, unless to a proper disposal facility.  You may be aiding the spread of tree disease and insect population.  This pruning must be done between October 1 and March 31, as the pruning cuts cause wounds that attract the beetles.  In line with several Albertan municipalities, St. Albert has established a bylaw, #5-98 (.pdf), that makes it illegal to prune Elms between April 1 and September 30 without expressed written permission from the City.

The tree maintenance crew at Public Works has established a collection point for Elm wood at the St. Albert Compost Depot.  All Elm wood and diseased tree prunings can be brought to the site and placed in the marked area.  This material is kept out of the compost  stream and burned.  This method of eliminating dead wood will help avoid attracting the beetle that could carry the disease and from providing a site the beetle could use as a nursery to increase its population.

Pubic Works prunes Elms annually on a rotating basis.  This consists of removing dead wood, crossed branches and for proper form and lifting of these trees.

Black Knot

Black Knot fungus (Apiosporina morbosa) is a common disease of the Prunus species (i.e. Schubert, Mayday and Plum trees).  The fungus forms swollen black cankers or "knots" on the stems and twigs of infected trees.  The disease can be spread to other trees of the Prunus family by rain, insects, birds and unsterilized pruning equipment.  Because it is known to spread rapidly it has the potential to seriously deform the trees and spread to other trees in the area.

To control black knot on infected trees, the City of St. Albert prunes trees for this disease every winter when the fungus is dormant.  The infected areas are pruned out and cuts are made at an optimum 12 inches below the infected area.  To ensure pruning equipment is properly sterilized after removal all equipment is washed down with a mixture of water and bleach (10%).  The multi-purpose cleaner, Spray Nine, is also effective.  Residents are asked if they are removing infected branches from their trees to bring them to the Compost Depot and place them in the diseased wood pile for proper disposal.

For more information on this disease please visit www1.agric.gov.ab.ca.

  

ISA Arborists

The City of St. Albert currently has three ISA Certified Arborists on staff.  This certification was developed for professional arborists in order to provide the public and those in government with a means to identify those professionals who have demonstrated, through a professionally developed exam and education program, that they have a thorough knowledge of tree care practices.  It is also designed to be an educational program that will improve technical competency of personnel in the tree care industry and create incentives for these individuals to continue their professional development.  Having these members on staff helps to better provide service to our residents and ensure best practices for the trees and shrubs within our city.

If you would like more information on the ISA (International Society of Arborists) please visit their website at www.isa-arbor.com.

Winter Tree Operations

The City Tree Services crews continue through the winter in several tree maintenance areas.

For many species of trees, fall and winter are the optimum time to apply structural and sanitation (dead wood removal) pruning.  The tree's structure is not obscured by leaves and any diseases are inactive and more identifiable.  Winter is the prime season for the structural pruning of most of St. Albert's residential boulevard trees.

Losses due to accidents involving trees are much more frequent during the winter months and crews react as necessary  to assess losses and perform repairs or removals as required.  As well, maintenance to the City's natural areas is often performed in the fall and winter.