Wednesday, May 23, 2012

Spraying Autumn Olive

I’m in the process of tracking down the rogue Autumn Olive that I cut and marked a few weeks ago, so I can treat the regrowth with glyphosate herbicide.  Even the most recently cut stems have produced suitably sized sprouts to receive a sufficient quantity of herbicide to be effective.  That’s not surprising since these aggressive invasive plants are nearly impossible to suppress.

I mapped the cut shrubs so I would be able to find them now.  The map shows the approximate location of the Autumn Olive and identifies the number of marking flags at the site.  I just have to get close and find all of the flags.  I didn’t remove the flags after spraying.  That will be done in a couple of weeks when I make my final check and treat any sprouts that managed to miss the spray application. 

Some stumps are slower to regrow than others.  The stump on the right was sprayed about a month ago.  At that time, the stump on the left was not showing any green growth.  It has obviously flourished since.  Autumn Olive has a habit of managing some new growth following a herbicide treatment, so it’s important to make a follow-up visit.  I try to make my final rounds during the first week of June.  Anything that’s going to grow will have done so by then.  It’s also important to get the flags collected before they are hidden by the rapidly growing vegetation.  The wire stemmed flags I put out this year amount to about a half mile of wire scattered around my fields.  I want to make sure it all gets removed.

While wandering around with my spray bottle, I treated a few other alien plants that have the potential for causing a disturbance to native ecosystems.  The large leaves of Common Burdock, Arctium minus, are a common sight around barn lots and farmsteads where they can reach impressive sizes.  The plant is a biennial and needs disturbed soil to provide a proper environment for seed germination.  In more natural landscapes, Burdock usually doesn’t reach the size or plant density displayed in disturbed areas.  It’s not at the top of the list as a noxious invasive, but it has enough negative qualities to make its elimination worth the effort.  The large leaves can create a dark enough shadow area that a bare spot is left when the plant dies.  The bare spot becomes an ideal seed bed for Burdock and other invasive plants.  The sticky seed heads are also a hazard to small animal life.  I have found the desiccated bodies of birds, bats and small mammals that became ensnared by the bristly hooks present on the seed heads.  Fortunately, this plant easily succumbs to a treatment of glyphosate.  A high percentage of the plants can be eliminated by applying glyphosate to just the central whorl of developing leaves.  The Burdock dies and incidental death of neighboring plants is virtually eliminated.

I also treated several Barberry shrubs.  These plants are fast becoming a problem in the woods.  I cut the Barberry off a few inches above the ground and applied glyphosate to the freshly cut stubs.  This treatment method is effective on many woody plants, but I’ve never before tried it on Barberry.  I thought this was a good time to put it to a test.  The plants were going to produce fruit this year, so cutting them eliminated the fruit and if the spray doesn’t kill them, at least it didn’t do them any good. 


  1. I wish I could do as well getting rid of what I don't want in my little garden.

  2. Thank you for these invasive posts. Very informative, inspiring, and helpful at approaching the problem.

    I personally have been clearing barberry, multiflora rosa, invasive honeysuckles (Lonicera tatarica), and chinese wisteria out of a urban backyard. This approaches have allow proper identification as well as removal approaches depending what else is growing nearby.

  3. Hi Lois. After I get Blue Jay Barrens cleaned up, I'll come in to town and take care of your garden. How about the second Sunday in May, 2043.

    Hi Pat. It's enjoyable work.

    Thanks Dave. I wish more people would take the initiative and control invasives on their property. Good Luck in your efforts.