Weed of the Month: Oxeye Daisy

Oxeye daisy (Leucanthium vulgare) is the dainty white flower that you see blanketing open fields in and around Wilson, giving the impression of snow in summer. 

Although a field of daisies may seem preferable to a field of spiny thistles, or bur-covered houndstongue plants, the impacts on native plant communities and the wildlife that depend on them are the same. 

The 50-ish invasive plants we are mandated to control in Teton County are so named because they don’t just colonize disturbed areas, they INVADE established native plant communities and displace native plants. The characteristics that allow oxeye daisy to invade include the ability to spread through underground rhizomes, a lack of palatability to wildlife and cattle, the ability to tolerate a wide range of soil conditions, and freedom from the predators and pathogens found in its native Eurasia.

Oxeye daisy belongs to a cohort of invasive plants that are often considered too pretty to be a problem. Along with  Dame’s Rocket, Dalmatian toadflax, and others, oxeye daisy is at risk of not being treated due to its perceived beauty and the fact that it is so easy to cultivate. 

Dames Rocket and Dalmatian toadflax are invasive plants that people hesitate to eradicate because of they are pretty AND very easy to cultivate 

But be warned, once oxeye has flowered and gone to seed on your property, you will have daisies coming up for many years to come. Once you start treating them, it will take at least 6 additional years to exhaust the seedbank. One study found oxeye daisy seeds to be viable in the seedbank for 39 years! So the sooner you begin treatment, the better.

Oxeye Daisy Treatment options include:

  1. Dig out entire patches, removing all rhizomes – expect to dig at least 6 inches down to get all rhizomes out.
  2. Spray with an herbicide like Opensight, which is available at TCWP. Repeat treatments in spring and fall each year until the seedbank is exhausted.

Finally, if you really want daisies in your yard, consider planting Shasta daisy. Like oxeye daisy, it is easy to grow, but it is not invasive. Here are some photos to help you differentiate these two daisies:

Can you tell which is which?