The City of Grande Prairie’s Parks Operations has several seasonal tree and plant maintenance reminders for residents as we transition into spring.

Black Knot

Pruning for Black Knot Disease

For owners of mayday, schubert chokecherry, pin cherry or plum trees, now is the ideal time to check for black knot disease and prune it out. The knots are more easily seen at this time of the year before trees grow leafs. Pruning it out before the warmer temperatures also ensures the fungus is still dormant and lessens spread.

To cut out black knot disease, cut knots a minimum of one foot below where they begin, preferably right back to the next branch. Disinfect pruning tools in between cuts with a 10% bleach solution or gas line anti-freeze. Use of pruning paint is not recommended. Pruned knots can be placed in garbage bags and disposed of in your municipal garbage.

Evergreen Winter Damage

Residents with evergreen trees may be noticing winter damage showing up as the weather warms, but are encouraged to properly confirm if the tree is dead prior to removing it. Evergreens can sustain significant winter damage and still continue to grow and recover.

Winter Damage on Pine

If your spruce or pine is showing symptoms of winter damage, please take the following steps:

  • ·Wait until spring is in full bloom to check for signs of life and new growth before making any decisions about removal.
  • ·If your tree is pushing out new growth, consider applying an evergreen fertilizer as soon as it appears to help the tree produce as much new growth as possible for a full recovery.
  • ·Monitor your tree throughout the summer. Drought may make your tree drop the new needles it has just produced, so watering deeply during dry spells helps maintain tree health and needle growth.
  • ·Applying mulch under your yard trees rather than grass helps keep the trees hydrated and prevents trimmer and mower damage.

Provincial Elm Pruning Ban

Homeowners are also reminded that the provincial elm pruning ban is back in place as of April 1, 2019 until October 1, 2019.  Residents with elm trees are not permitted to prune the trees during this time so as to deter the spread of Dutch elm disease.

Elm bark beetles, which carry Dutch elm disease, are attracted to the smell of freshly cut elm wood, so the pruning ban helps reduce beetle spread. Elm bark beetles were found for the first time in Grande Prairie in 2017, but no Dutch elm disease has been found as yet. Grande Prairie’s urban forest contains more than 3500 elm trees worth over $4 million.

For more information on trees, pruning and disease control, please visit cityofgp.com/parks.