Garlic Mustard Threat to Loree Forest

Invasive Garlic Mustard plants in bloom. Photo credit David Cappaert, bugwood.com
Garlic Mustard plants in flower. Photo credit: David Cappaert, Michigan State University, bugwood.org

Every native plant species in the beautiful Loree Forest is threatened by an invasive weed, Garlic Mustard. This aggressive plant wipes out all indigenous plants in its path. It has been gaining ground in Loree Forest, despite annual pulling of the weed.

Why is Garlic Mustard so Bad?

There are lots of reasons why Garlic Mustard is such a aggressive plant. Here are the biggest ones:

  • It thrives in virtually any environment. Sun and shade. Wet and dry soil. Clay soil and peaty soil. Acid and alkaline soils. Forest and field.
  • Garlic Mustard is not a valuable food source for wildlife or insects. Chemicals in the leaves make it distinctly unappetizing to herbivores.
  • Each plant produces between 200 and 800 seeds. Seeds in the soil remain viable for 5 to 8 years. If the soil becomes disturbed, the sleeping seeds wake up, with a vengeance.
  • Garlic Mustard displaces all of its neighbours. The plant changes soil chemistry around it, preventing other species from growing nearby. Chemicals emitted by its roots kill soil fungi that feed our giant trees.
  • Its height and dense growth habit starves tree seedlings of the sunlight needed to grow. Without young trees to replace older ones as they die, Garlic Mustard eventually turns a forest into a field. A field of Garlic Mustard.
  • Garlic Mustard spreads fast! It roughly doubles its range every 4 years.

Controlling the Spread of Garlic Mustard

Without chemical solutions to control Garlic Mustard, our only option is to disrupt the Garlic Mustard cycle before the plant sets seed in the spring.

  • Pull Garlic Mustard plants out of the ground, being sure to get the root crown (or it will regenerate the same year). Plants are easy to pull as the ground is usually still moist.
  • Cut plants down before they go to seed in the spring. Its a much less effective option, but it does slow its spread.

What can I Do About Garlic Mustard?

  • When hiking, be sure to clean your boots off before moving on. The seeds picked up on hikers’ boots are one of the main ways the plant spreads from one area to the next.
  • Pull it from your own property if you find it. If you have a large infestation, start at the edges and move inwards towards the centre. This prevents wider spread.
  • Join one of the “pull parties” organized each spring before the plant goes to seed.

How Can I Identify Garlic Mustard?


Tour our New Wodehouse Karst Side Trail

Stew Hilts
Photos © Stew Hilts

Wodehouse Creek disappears into sinkholes in this blind valley

Take a peek at the new Wodehouse Karst Side Trail just opened this spring!