The most humble, resilient and cheerful meadow wildflower.
Like self heal and cinquefoil, yarrow is a defining meadow plant. Thriving in disturbed sites and in wet or dry soils, yarrow competes well with grass and defies deer to eat it. The only thing this long blooming wildflower does not cope well with is shade.
On warm summer mornings, the unpretentious flowers host fantastically small syrphid flies, ants, and tiny Lasioglossum bees. Look closer and you may find the most perfectly camouflaged miniature predators: tiny ghostly white crab spiders and motionless ambush bugs.
This highly aromatic plant is packed with flavinoids, resins, and essential oils, all of which have long made it popular in folk medicine. These same aromatics make it an interesting fresh cooking herb, although it can quickly overwhelm and it's best in small doses. Add a small amount to fresh dill for excellent homemade gravlax. Or mix a little with lots of more neutral greens such as parsley or nettle for a sublime pesto.
Plant this for natural pest control around the garden. Plant it for Achilles who used it to staunch the wounds of his soldiers in battle. Plant it because it is one of our few native wildflowers that refuses to buckle under the pressure of introduced grasses and weeds.