Is yarrow invasive?
Common yarrow (Achillea millefolium) is generally not classified as an invasive species, but it can be an aggressive spreader in gardens and lawns. The answer is complicated by the plant’s range: yarrow occurs across the Northern Hemisphere, and in North America it is treated as native in many places while European forms have also been introduced. Local invasive lists rarely include it, but check with your state, province or county if you want to be certain.
This is the kind of case explained in invasive vs aggressive plants: a vigorous plant that is not necessarily causing ecological harm.
Is yarrow a native plant?
Often, yes. Regional native plant sources, including the Washington Native Plant Society’s directory, list common yarrow as native in their areas. At the same time, many named garden cultivars, with colors such as red, yellow, coral and pink, descend from European or hybrid stock and are sold as ornamentals. If native status matters to you, ask a local native plant nursery for regionally sourced yarrow and do not assume that every yarrow at a garden center is local.
How yarrow spreads
- Rhizomes: underground stems form expanding mats.
- Seed: flower heads produce many tiny seeds that can sprout nearby if not deadheaded.
- Toughness: it tolerates poor, dry soil and recovers after mowing, which helps it persist in lawns.
Some cultivars are less vigorous than the species, but results vary with soil and climate. Rich, moist soil can make plants floppy and more prone to spreading.
Keeping yarrow in bounds
- Give it a defined spot, such as a dry, sunny border, rock garden or meadow patch, not a tight bed with delicate plants.
- Use a root barrier or edging sunk several inches into the soil if rhizomes are a concern.
- Divide clumps every few years and remove the edges that run.
- Deadhead spent flowers if you do not want self-sown seedlings. You can leave some heads in fall for birds and insects.
- Avoid rich soil and heavy watering, which encourage lush growth.
What kills yarrow?
If you want to remove it:
- Dig out the plant, including rhizomes. Small pieces left behind can resprout, so expect to repeat the process.
- Smother an area with cardboard or thick mulch for a season, then check for shoots.
- Mow or cut repeatedly to weaken plants in a lawn, and improve turf density so grass can compete.
- Herbicide is a last resort. If you use one, follow the product label and local rules.
Persistence matters more than any single method. Replace the space with something else so yarrow does not return.
Yarrow as a pollinator plant and lawn alternative
Many gardeners keep yarrow on purpose. Its flat flower clusters attract a variety of small bees, flies and beneficial insects, and it handles drought. Some people use it as a low-mow lawn alternative or in meadow mixes. That makes it a candidate for dry, sunny sites where other plants struggle.
Is yarrow smokable? What are the side effects?
Yarrow has a long history of traditional use, and you will find claims online about smoking or consuming it. This site focuses on gardening, and we cannot give medical advice. Some people are allergic to plants in the daisy family (Asteraceae), which includes yarrow, and contact or ingestion may cause reactions in sensitive people. Yarrow is also listed as toxic to some pets and livestock by animal-poison resources such as the ASPCA. If you are thinking of using yarrow medicinally, talk with a qualified health professional first, especially if you are pregnant, taking medication or have allergies.
Alternatives and companions
If you want a similar look with different behavior, consider other regional natives with flat-topped flowers, though some native asters and goldenrods are also aggressive spreaders. Our guide to invasive vs aggressive plants can help you judge what suits a small bed.