The Town of Stony Plain's Parks Crew is responsible for maintaining public green spaces, multi-use sports courts, a skate park, a dog agility park, and Stony Plain's trail system.  Over the winter months, the crew ensures the trails are clear of ice and snow and maintains four outdoor rinks and two ice skating trails.

Horticulture plans and maintains Stony Plain's tree inventory, public land shrubs, and flower beds, as well as planters and hanging baskets.  Horticulture coordinates the barrel planter sponsorship program and is responsible for pest control, such as beavers, in the town.

Pruning Zone Map

Black Knot

Black Knot Disease

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.

Plant Species

Amur Cherry

Black Cherry


Flowering Almond


Flowering Plum

Dropmore Cherry

Japanese Plum

Korean Cherry

Mayday Tree

Mongolian Cherry

Cultivated Plum

Nanking Cherry

Wild Plum

Pin Cherry

Prunus Hybrids

Sand Cherry

Sour Cherry

  Black Knot Disease

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.

Black Knot control

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


Dutch Elm Disease
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 |

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.

Weed Control

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:

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.  

We are currently pruning in:

Zone 1 Completed October 2023
Zone 2 Completed October 2023
Zone 3 Completed October 2023
Zone 4 Completed October 2023
Zone 5 Completed October 2023

To report weed complaints and damaged trees, you may submit a request through Report a Problem - Stony Plain.