O my gosh I have so much naturally growing yarrow here! I have replanted it in my garden because it helps with bug reduction. I do yarrow and, first year I have started, wormwood in the herb garden as a pest deterrent.
I love the smell of yarrow. I have so many jars of those little white flowers lol, I need to stop harvesting some of these herbs. Maybe this year I will do a fresh herb side of the table at the farmer's market.
Wormwood is a good pest deterrent, and dehydrated, can be fed to layers in winter for worm/parasite control. Just feed sparingly, and so it is free choice.