Do Yarrow Plants Spread?

Yarrow opens flowers in summer over a period of four to six weeks or more. ... Common yarrow spreads by self-sowing and underground stems. Self-sowing is easy to control—simply snip spent blooms. It's important to remove spent flowers in yarrow varieties and hybrids to prevent plants from reverting to the parent form.

Does yarrow multiply?

Yarrow is said to have a propensity for crossbreeding, so if you do let the plant self-sow, you might end up with plants that have reverted to their parent form, namely the wild yarrow with white-gray blooms.

Is all yarrow invasive?

Common yarrow is a weedy species and can become invasive. Proper care should be used to control the spread of the plant from its desired growing location. Common yarrow may suffer from mildew or root rot if not planted in well-drained soil. These materials are readily available from commercial plant sources.