5 September 2023

Here’s a pretty though invasive alien that I’ve not seen in Pittsburgh but is easy to find in Lancaster County, PA where I took this picture.

Beefsteak plant (Perilla frutescens) is a member of the mint family native to Southeast Asia and the Indian highlands and is grown as a crop for Japanese, Korean and Chinese cuisine. Its common names include shiso, Korean perilla or simply perilla. The “beefsteak” name was coined because the darkest varieties have leaves as red as meat. The wild plants I saw in Lancaster County had green leaves and dark red stems.

Perilla frutescens is widely cultivated in Asia as an edible plant but it has some downsides if you don’t know what you’re doing, such as: “Contact dermatitis may occur in people handling the leaves or oil. Consumption of large amounts of seeds has resulted in anaphylaxis.” — Wikipedia The plant is always toxic to cattle, horses and other ruminants including white-tailed deer.

Brought to the U.S. as an ornamental, perilla escaped to the wild and, as of May 2026, is listed invasive in 11 states from Michigan to South Carolina.

Since deer don’t eat it, it may have been touted as “deer resistant” at the plant nursery but don’t buy it for that reason. In North America this plant spreads way too easily.

UPDATE in May 2026: Perilla moves rapidly and has nearly doubled its invasive footprint in only three years, 2023 to 2026. Click here to see the map in 2023.