What is the species?
- Lamiastrum galeobdolon (yellow archangel)
- ODA “B” rank
Yellow archangel is a ground cover native to western Europe. It has become very popular in recent years, and is seen in natural areas around the Portland area.
Why are we concerned?
Yellow archangel infestations can lead to:
- Reduced plant and animal diversity as other species are displaced
- Reduced ability to replace adult trees as seedlings fail to mature
How does it spread?
Yellow archangel spreads by seed, and also aggressively expands along the ground. Its color and hardiness make it a popular swap species among gardeners, and for many years archangel was a common “filler” in hanging baskets. Yellow archangel seeds and plants move by:
- Vegetative expansion
What does it look like?
Yellow archangel typically has heavily variegated [green and white] leaves, though not always. It has square stems and distinctive yellow flowers in early summer.
Are there any lookalikes?
Yellow archangel might be confused with goutweed, with similar hardiness and tendency to overwhelm spaces. The variegation [white coloring] in archangel leaves can account for more of the space on the leaves; goutweed’s tends to stay around the edges. Yellow archangel’s larger, yellow flowers are also quite different from goutweed’s smaller, white flowers.
How do we deal with it?
- Manual: Digging up yellow archangel can be effective. Like ivy, pulling archangel requires attention to detail and repeated visits. Excavated plants and cut flowerheads must be bagged and put in the garbage to prevent spread to new areas.
- Herbicide: Herbicide has limited effect in managing this species.
How can folks help?
Yellow archangel is not a species that the city is currently managing on private property. Private property holders are, however, strongly encouraged to manage and properly dispose of archangel.