Plants and Trees

Shrub beds require regular pruning, watering, mulching, and weeding. Removing them saves time and effort. The Parks and Horticulture team is working to reduce the number of Priority 2 shrub beds in subdivision and park areas.  This initiative provides more time for crews to focus on the Priority 1 shrub beds.  

During this process, the area is evaluated and some shrubs are removed and transferred to a storage area where they are maintained for future use. All trees remain in place while the ground is leveled and prepared for grass seed or sod. Over the season, the space is transformed from a shrub bed full of grass and weeds to an easily maintained grass area.

Black knot (Apiosporina morbosa) is a fungal disease that causes greenish brown to black swellings in the stems of cherry trees (Prunus spp.). Its spores are released following periods of warm, wet weather and are spread by splashing water, wind, birds, and insects.

Black knot is an increasingly common disease. Early detection and sterile pruning is the most effective way of dealing with this problem.

The problem, Black knot deforms branches and reduces their growth. Heavily infected trees often become stunted and may eventually die. 

Black knot is not regulated through any legislation. It is a native plant disease that is well established throughout the province.

Plant Species

Amur Cherry	Black Cherry	Apricot
Flowering Almond	Chokecherry	Flowering Plum
Dropmore Cherry	Japanese Plum	Korean Cherry
Mayday Tree	Mondgolian Cherry	Cultivate Plum
Nanking Cherry	Wild Plum	Pin Cherry
Prunus Hybrids	Sand Cherry	Sour Cherry

  
  

What does the disease look like?

Initially, a small, olive green growth will develop at a succulent growing point or a short twig that bears fruit buds. This swelling will grow until it is mature after 2 to 3 years. The mature growths are hard, black, 10 to 15 cm and may be somewhat ruptured. They will produce and release a vast amount of spores during the bloom period, resulting in a rapid increase of infections. The fungus continues to grow internally and externally, with the branch eventually becoming covered all around and dying.

What the Town is doing

• Town crews will continue the ongoing monitoring and pruning program for susceptible trees on public property
• Black knot pruning rotation is broken into 5 zones. Crews will start with zone 1 in fall 2023. To ensure the completion of this operational work plan, no pruning will be done outside the current zone of focus
• Pruning for black knot takes place between late fall to early spring when the tree and spores are dormant and when the knots are easier to see
• Only Town crews are authorized to prune infected trees on public property
• Pruning tools and equipment are sterilized between each cut using an approved environmentally-friendly solution which prevents the spread of the disease
• While black knot is managed and pruned from Open Space and Boulevard trees. Black knot in Natural Areas will only be managed if the tree presents a safety risk

What can you do to control the disease?

Regularly monitor your cherry tree(s) for symptoms of black knot. Early on, the disease appears as small light brown swellings, usually found on new green stems. As the knots mature, the swellings will appear olive green with a velvety texture. Eventually, the knots darken and harden. If you detect black knot, follow the guidelines below:

• You can help to maximize the impact of the Town’s black knot pruning efforts by ensuring trees on private property are pruned for black knot
• Prune out the infected branches between late fall and early spring when the plants is dormant and knots are easier to see
• Remove infected branches to at least 15-20 cm (6-8 inches) below the knot
• It is best to prune an infected branch further back to the next branch or to the trunk, rather than leave a stub
• Sterilize your cutting tools between each cut using bleach to prevent further spread of the disease
• Destroy infected prunings immediately, as they can continue to produce spores for months after being removed
• All diseased wood should be burned or buried. Do not place wood in the organic bins. 
• A list of tree pruning companies is available on the Better Business Bureau website.

The Town of Stony Plain is one of 112 municipalities that participates in the STOPDED program. 

What is Dutch Elm Disease (DED)

DED is a costly, deadly disease that affects all species of elm trees in Alberta. It is caused by a fungus that clogs the elm tree's water conducting system, causing the tree to die. The fungus is primarily spread from one elm tree to another by 3 beetle species. The beetles are attracted to weak and dying trees, which serve as breeding sites. Once the beetles have pupated and turned into adults, they fly to healthy elms to feed, transporting the fungus on their bodies from one tree to the next.

Best practices

‘Elm tree’ means any tree or part of a tree of the Ulmus genus and its cultivars, including the American, Siberian and Japanese elm. Follow these best practices to help keep elm trees healthy and less susceptible to DED:

• Keep your elm trees healthy, vigorous and properly pruned
• Water elms from April to mid-August. To allow the tree to harden off for the winter, stop watering in mid-August, followed by a good soaking or 2 before freeze-up

Elm pruning

Pruning elms can only be carried out commencing October 1 to March 31 the following year.

For additional information on STOPDED check out Dutch Elm Disease | Alberta.ca.

Elm pruning ban

Pruning ban period means the period commencing on April 1 and ending on September 30 of the same year. Elm bark beetles (EBB), the vectors of DED, are active between these dates and can be attracted to the scent of fresh tree cuts, possibly infecting a healthy tree.

Weeds, or invasive plants, are non-native plants that adapt quickly and aggressively to the Alberta landscape causing lasting damage.

The negative effects of weeds include:

• Reducing the habitat available for native plants species, which in turn threatens species of insect, plant, fish and animal that depend on native plants
• Reducing property values for residents and agricultural producers
• Production from agriculture and forestry industries
• Increasing land management expenses for counties and municipalities, businesses and property owners

We all have a role to play in response to weeds. Here's how:

Prevention and control for gardeners and landscapers

• When planting, choose plants that are Alberta native species – they're adapted to thrive and are better for supporting our province's bees, butterflies and birds
• When buying soil, sand or gravel, select a company that practices good weed control
• Scrutinize seed packets as they may include the seeds of invasive plants. Use local seed mixes or buy individual species to make your own mix
• Before going to the gardening centre, brush up on your knowledge of native and invasive plants:

Learn more about Alberta native plant species:

• Alberta Native Plant Council
• Alberta Invasive plants

We remove and control restricted and noxious weeds in our community. Restricted weeds are removed as they are a threat to the environment and noxious weeds are controlled to prevent rapid spreading. 

Signs will be posted when weed spraying occurs.  

public-tree-bylaw-2647-g-21.pdf

Some highlights from the Bylaw

4.0.0 Planting

4.1.0 No person shall plant Trees or Shrubbery on Town Lands or cause Trees or Shrubbery to be planted on Town Lands without prior written authorization from the Manager. 
4.2.0 Written authorization to plant Trees or Shrubbery on Town Lands does not relieve a Person from obtaining any other approvals which may be required under any other Regulation. 

7 .0.0 Disease Control

7.3.0 No Person shall Prune an Elm Tree between April 1 and September 30 in any year unless Pruning is explicitly authorized in writing by the Manager pursuant to section 7.4.0.

8.0.0 Maintenance of Public Trees

8.1.0 The operations department is responsible for all Public Tree maintenance with the exception of 8.2.0. BYLAW 2647/G/21 
8.2.0 The closest property owner shall maintain all Trees or Shrubbery withing the area between the  property line and the nearest concrete structure within the road right-of-way being a trail, sidewalk, curb or street. 
8.3.0 Where a Tree has branches or foliage, which protrude over a street, sidewalk or trail, the following clearances must be maintained:

a) a minimum of 12 ft vertical clearance over a street; 
b) a minimum of 7ft vertical clearance over a trail. 

Gather and Grow Day combines two beloved annual events: Neighbours' Day and Arbour Day. This event features all the elements that the community enjoys from both Neighbours' Day and Arbour Day, including opportunities to connect with community members and become Neighbourhood Connectors, tree planting, crafts, and opportunities to prizes. Attendees are encouraged to bring a painted rock to contribute to the creation of a 'rock snake,' which will be assembled in the park during the event.