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.

Oxeye Daisy

After mowing a field in the winter, I should be able to enjoy the greening of the field in the spring followed by the prairie flowers of summer that are slowly hidden by the late summer tall grasses. All of those things will occur this year, but they are being joined by an unwelcome event. Those patches of white in the field aren’t reflections of clouds. They are rafts of Oxeye Daisy, Chrysanthemum leucanthemum, that have invaded the fields. It may be a favorite flower of many people, but Ohio Revised Code officially lists it as a noxious weed. It’s discouraging to have someone look at your field, point to the Oxeye Daisies and say “Oh, aren’t those beautiful. Where can I get plants like that?”

I was on a naturalist led hike about 25 years ago and commented on Oxeye Daisy growing in one of the Ohio barrens. I was told that it wasn’t a concern because it just filled in the voids and didn’t seem to be displacing any of the native flora. I think we’ve now learned that to be an inaccurate observation. This field is not one that you would consider to have voids. What it had was an opportunity for this aggressive early season plant to establish itself before the warm season prairie species began to grow.

Oxeye Daisy does have a nice flower and many people welcome it into their fields for that reason. This is the one flower that I told my kids they could pick at any time without asking. Picking obviously didn’t slow down the spread. Each flower head will produce many hundreds of seeds, all of which easily produce new plants.

Besides being an excellent seed producer, Oxeye Daisy is a perennial that can spread by the production of rhizomes. Once a plant is established, it proceeds to expand into the surrounding areas. The plant is easily pulled because of its shallow root system, but any rhizome pieces left in the soil quickly produce new plants.

This is going to be a tough plant to deal with. Spraying won’t work because too many other plants would be affected. Pulling, if you had the time and manpower for the job, would not work because you would always be leaving bits of rhizome to grow back. Mowing during the growing season would probably favor Oxeye Daisy, because it easily grows back from the basal stems. Goats would favor the Oxeye Daisy over most early growing plants and could reduce the number of plants over time. Maybe I’ll get a couple of goats and let them work on the areas of worst infestation. I guess I’ll have to find time in my schedule to try out a few control strategies on this newest invader.