Most yarrows grow 2 to 4 feet tall, although low-growing varieties are also available. The plants are remarkably durable, tolerating dry spells and low soil fertility where other perennials would fade. Yarrows bloom from midsummer into fall; flower colors include red, pink, salmon, yellow, and white. Yarrow are versatile and look equally at home in a perennial border, sunny rock garden, or wildflower meadow. Powdery mildew disease may be a problem in humid areas.
Special features of yarrows
Easy care/low maintenance
Good for cut flowers
Tolerates dry soil
Choosing a site to grow yarrows
Select a site with full sun and very well-drained soil. Yarrow thrives in hot, dry conditions and low soil fertility, but won't tolerate wet soils.
Apply a thin layer of compost each spring, followed by a 2-inch layer of mulch to retain moisture and control weeds. Water plants during the summer if rainfall is less than 1 inch per week. After the first killing frost, cut stems back to an inch or two above soil line. Divide plants every 3 to 4 years as new growth begins in the spring, lifting plants and dividing them into clumps.
Plant in spring, spacing plants 1 to 2 feet apart, depending on the variety. Prepare the garden bed by using a garden fork or tiller to loosen the soil to a depth of 12 to 15 inches, then mix in a 2- to 4-inch layer of compost. Dig a hole twice the diameter of the pot the plant is in. Carefully remove the plant from its container and place it in the hole so the top of the root ball is level with the soil surface. Carefully fill in around the root ball and firm the soil gently. Water thoroughly.