Seedy Season

Monday, May 28, 2018

As gardeners get back to work, so do weeds and arbour diseases. The City of Leduc needs help from residents to keep trees healthy and stop the spread of weeds. Keep an eye out for common symptoms.

Noxious Weeds

Harmful, invasive plants are defined as noxious weeds in Alberta’s Weed Control Act. Some weeds are already present in Alberta (noxious), and others must be kept out (prohibited noxious). If spotted, residents must immediately pull these weeds and bring them to the City of Leduc’s diseased wood pile. Do not throw them in the green bin. Under the city’s Community Standards Bylaw, Enforcement Services gives residents 14 days’ notice to control or destroy noxious weeds to avoid penalty.

Some noxious weeds to look for and control by trimming or uprooting include: Canada thistle, yellow toadflax, common tansy and scentless chamomile. Himalayan balsam and other prohibited noxious weeds must be uprooted and destroyed if found.

Nuisance Weeds

Dandelions, broadleaf plantain and white clover are non-regulated nuisance weeds. Keep long grass and nuisance weeds shorter than 10 cm. If grass and weeds are taller, Enforcement Services issues an order to comply with the Community Standards Bylaw and manage the weeds or grass within 14 days to avoid penalty.

The city does not spray neighbourhoods for dandelions because they are not considered noxious weeds. Herbicides are used in a target-specific manner on athletic fields and around city facilities.

Arbour Diseases and Pests

Black knot fungus is a dark, rough growth that can form on prunus trees. Effected branches should be pruned at least 10 cm below the fungus and brought to the diseased wood pile. Remember to disinfect tools with bleach or alcohol and transport the branches in a plastic bag to prevent spread.

Elm scale is a dark insect that feeds on elm sap. Trees with deep infestations have barnacle-like scale insects and a sooty appearance on the bark. Remove the insects by hosing down or pressure washing with water, or calling a professional. Keep elms healthy to avoid infestation by watering them well and often.

To prevent Dutch elm disease, a fungus spread by elm bark beetles, the City of Leduc has an elm pruning ban between April 1 and October 1. Let elm trees grow during the summer.

Diseased Wood Pile

It’s important to bring all diseased wood and noxious weeds to the diseased wood pile. It can be found down the road from the Stone Barn at the east end of 48th Ave., behind the sports fields in William F. Lede Park. Remember to transport the weeds and branches in plastic bags to prevent the issues from spreading in the community.

Share pictures of your garden progress on social media using #lawnleduc. For more information about lawn care and bylaw enforcement, visit