‘Moonshine’ is probably the epitome of fernleaf yarrow, Achillea filipendulina, even though it is technically a hybrid. From the middle to the end of summer, its three inch wide corymbs (flat-topped trusses) of tiny bright yellow flowers stand as high as three feet above ferny and gray basal foliage. Bloom is best in full sun and warm exposure. Established plants do not need too much water.
Most varieties of fernleaf yarrow also bloom with bright yellow or gold flowers. Some might bloom with pale yellow, rosy pink, pale pink, reddish, white or pink and white flowers. All are good cut flowers, and can be dried. Some varieties are more compact. The most compact varieties work nicely in planters of mixed perennials. Butterflies and hummingbirds find them wherever they are.
Pruning out deteriorating blooms may promote sporadic subsequent bloom until autumn. However, some plants may bloom all at once, and then not bloom again until the following summer. Large blooms on the most vigorous plants may need to be staked. New plants can be propagated by division from mature plants. ‘Moonshine’ and many other cultivars are sterile. Others might self sow.