Last spring I got some yarrow from a friend of ours. I jumped the gun and planted it before the fence to my garden was up. Then the fence got made, involving a backhoe in the garden. The yarrow got ran over multiple times. However, it came back. I never went out of my way to water the yarrow, as it was at the far north end of my garden; the area where a small child plays and where 3 dogs run through. The yarrow got stepped on, ran over, not watered, and played with daily. Basically, it was a neglected self sufficient plant which survived EVERYTHING! It died a little because I hadn’t watered it and then we got some good rain and it came back to life. It even died down and then came back late summer, early fall. It’s indestructible!
I had a purple variety and a white one. In the picture below, it is actually purple but the glow of the evening sun gave it the beautiful pink shade!