Skip to main content
perilla mint

Scout Pastures for Toxic Perilla Mint this Fall

Perilla mint in a pasture in Jackson County. Photo credit: Doug Mayo

Perilla mint in a pasture in Jackson County. Photo credit: Doug Mayo

Documented distribution of perilla mint in Florida. Source: Atlas of Florida Vascular Plants.

Documented distribution of perilla mint in Florida. Source: Atlas of Florida Vascular Plants.

Perilla mint (perilla frutescnes) aka Beefstakeplant is a toxic weed that typically grows in shady, to partially shaded areas, damp spots, woodland edges, and  fence-lines of pastures in the Southeast. Positive identification of this weed has been made in a number of Panhandle Counties, as can be seen in the map developed by the Atlas of Florida Vascular Plants.  This does not mean that this weed is not present in the other counties, just that the herbarium has not received samples from those counties.

Livestock will typically avoid grazing perilla mint.  You may have some growing in your pastures, and still not have a problem.  Typically livestock poisonings occur in the fall and early winter, when livestock can become hungry from an inadequate feed supply.  The best way then to prevent livestock poisoning from perilla mint and other toxic weeds, is to make sure there is an ample supply of fresh grass or hay continuously available.  Even so, it is also advisable to scout for this and other toxic weeds and control them with herbicides labeled for pasture use.

The J.B. Taylor Diagnostic Laboratory in Elba, Alabama has recently received necropsy samples from cows that died from grazing perilla mint on two different farms.  Dr. Joel Cline, DMV, Director of the lab, reports that August through October is typically when they diagnose cases of perilla mint poisonings.  He said that “Livestock poisoned by perilla mint have respiratory problems from lung lesions,  with symptoms similar to pneumonia.”  He advises, “Handle cattle gently if you suspect they have grazed perilla mint.  Many times the stress of moving cattle too quickly to the cowpens for treatment is the ultimate cause of death.”

Identification of Perilla Mint

Undersid of a perilla mint leaf showing the reddish to purple color that is unique to this member of the mint family. Photo credit: Doug Mayo

Underside of a perilla mint leaf showing the reddish to purple color that is unique to this member of the mint family. Photo credit: Doug Mayo

As a member of the mint family of plants, it has the typical square stems.  Leaves are oval, pointed and somewhat heart shaped with serrated edges.  The stems and undersides of leaves have a purple to reddish hue.  Perilla mint typically grows to a height of three to four feet tall.  Flowers are pink to purple, and grow along terminal spikes up to six inches long.

Perilla mint has square stems with a reddish to purple tint. Photo credit: Doug Mayo

Perilla mint has square stems with a reddish to purple tint. Photo credit: Doug Mayo

Perilla mint  Photo Credit: Tennessee Vascular Plants Eugene Wofford

Periila mint flower. Photo Credit: Tennessee Vascular Plants Eugene Wofford.

Perilla mint flower. Photo Credit: Tennessee Vascular Plants Eugene Wofford.

Control of Perilla Mint

While livestock may not normally graze perilla mint, why not remove the risk?  Even one livestock death, or serious illness is too many.  Perilla mint can be controlled with several common herbicides, labeled for pasture use.  GrazonNext, Milestone, Weedmaster, and 2,4-D will provide good control of Perilla Mint .  (Source:  UT Extension Weed Management in Pasture and Hay CropsAt the very least these weeds should be mowed, or physically removed before or during flowering, to prevent seed production.

To learn more about perilla mint, download:

Poisonous Plants of the Southeast: Perilla Mint

Perilla Mint Toxicosis

Beefsteak-plant, Perilla Mint

 

5 Comments on “Scout Pastures for Toxic Perilla Mint this Fall

  1. This mint weed has taken over our pasture. Please recommend a poison that will kill it but safe for goats, dogs, cats. Thank you for your help.

    Sent from my iPadThis knot weed has taken over our pastures.

    • Perilla mint can be controlled with several common herbicides, labeled for pasture use. GrazonNext, Milestone, and Weedmaster will provide good control of Perilla Mint. None of these products have grazing restrictions, so technically you can treat with the animals in the pasture. There are haying restrictions of 7 days for GrazonNext and Milestone, and 37 days for weedmaster. The labels do not mention dogs and cats. I would suggest keeping all animals out of a pasture the day the herbicide is applied, but once it has dried, there should not be a problem.

  2. If I mow Perilla Mint how long do I need to leave cattle off of the pasture. If mowed does it still have toxicity and if so how long.

    Thanks
    Henry Smith

    • The dried material is toxic, but is of less risk than the fresh materials. Here is a UT publication to view: https://extension.tennessee.edu/publications/Documents/W135.pdf This is a direct quote from that publication: “All plant parts are toxic, especially the flowering structures. Dried plants in hay can be toxic, but the greatest risk is associated with consumption of fresh plant material, especially if flowers and fruit are present.”

Leave a Reply

Your email address will not be published. Required fields are marked *