Oxeye Daisy

I’ve discussed Oxeye Daisy before.  I use the old G & C name of Chrysanthemum leucanthemum, but the currently accepted name is Leucanthemum vulgare.  Many people find this invasive species to be attractive, but it’s nasty enough to have been declared by the State of Ohio to be a noxious weed.  This perennial plant of early summer is on my mind every year as the blooms spread a wash of white across the Blue Jay Barrens fields.  My primary thought is a single question:  How do I get rid of this plant without disturbing everything else in the field?

It would be nice if these weevils, found on just about every Oxeye flower, actually killed the plant.  The weevils make a meal here, but do nothing to keep each plant from producing thousands of seeds each year.

Oxeye Daisy isn’t a mere casual occurrence.  The fields are full of them.  If I were managing for cropland, hay or pasture, I could easily get rid of the invaders.  It’s much more difficult to try to erase a single species from a diverse collection of native plants.

Many years ago, I was on a tour that included a prairie opening full of Oxeye Daisies and the question came up about possible harm to the prairie from these abundant plants.  Our guide told us that the Oxeye wasn’t a problem because it didn’t compete with the existing plants.  I don’t believe there’s any non-competitive plant.  Every plant uses resources that could be used by some other species.  Vigor displayed by one plant means that there must be decline in another.  The fact that all visible plants look healthy shouldn’t be interpreted to mean that no plants have suffered.  It’s hard to see plants that no longer exist.

Some areas show very little infestation.  The fact that these sites also display a different plant composition than the surrounding area suggests that there may be some soil related conditions that aren’t as suitable for certain plants to grow.  A detailed soil investigation may be in order here.

New plants can develop from seeds, but the large masses of plants are the results of spreading rhizomes.  In this example, what was once a single stemmed plant has sent rhizomes in eight different directions.

What was a single stalk last year, is now a group of eight.  Each stalk becomes an independent plant as the rhizomes produce new roots. 

Pulling the plants by hand could offer some control, but it would not be an effective method of eliminating the plant from the field.  Both the stem and rhizome are quite brittle and easy to break.  Even if you managed to pull out some roots, there would be enough rhizome left to grow a new plant.  I pull Oxeye Daisies that I find growing in areas not yet infested by the species.  I hope this will slow their advance into new territories.

In areas like this, all I can do is stand and stare.  The only good thing is the fact that most of the native plants are able to compete well enough to maintain a good diversity of species in the field.  In disturbed ground, Oxeye Daisies are able to form solid colonies that preclude the colonization of other species.  In a stand of existing vegetation, the best they seem able to do is become another member of the group.  For now, I’ll keep thinking about this species.  Maybe by the time I’ve eliminated all of the other invasive species at Blue Jay Barrens, I’ll have an answer for this one.