Sunday, January 28, 2018

Battling Invasives

Invasive species are making Canal Shores unhealthy.  In our interactions with the experts, we have learned that a healthy ecosystem has layers, each layer ideally containing a variety of species:
  • An herbaceous (ground) layer of grasses, flowers and groundcover that are the home to pollinators and other important insects and animals.
  • An understory (shrub) layer of small trees and shrubs that provide food and habitat for birds.
  • A canopy of trees, of varying species and age.
The primary problem that Canal Shores has with its invasives is in the understory, specifically with buckthorn and honeysuckle. That problem has manifested in three ways:
  • First, within the understory, buckhthorn and honeysuckle are extremely aggressive competitors and they have left us with almost no other shrubs, greatly decreasing biodiversity.
  • Second, they form dense thickets, starving the herbaceous layer of sunlight. Where buckthorn grows densely, there is bare ground underneath which also creates erosion problems on the canal banks.
  • Finally, the buckthorn and honeysuckle leave no space for desirable trees to regenerate.
There are good reasons why it is illegal to sell or plant buckthorn or honeysuckle in the state of Illinois. They are parasitic plants that take over and leave the areas they populate in much worse health.

Not only is buckthorn bad for the other plants around it, but the berries produced by the females have a laxative effect on birds, while providing no nutritional content.

Many thanks to Brandon from Ringers Landscaping for allowing us to share his webinar. We highly recommend watching at least the first 18 minutes.

The work is well underway on holes 2, 3, 4, 5, 8, 9, 12-18. We have applied for a burn permit from the EPA to deal with the cut brush. We are also recruiting a Landscape Architecture / Ecology intern whose focus will be on maintenance of cleared areas as well as site-specific habitat design and implementation.

Decades of neglect and mismanagement are not going to be undone overnight.  However, we have made a beginning and we will continue working toward our goal of making Canal Shores a healthy ecosystem that includes a variety of native and other desirable trees.

We hope that all members of the Evanston-Wilmette community join us. Check back here regularly for dates of upcoming volunteer work sessions, or join our volunteer mailing list.  Inquiries about tree donations can be made with Dan Bulf ( This is a big job, but together, we can do it.