9 Best Yarrow Plants for Heating up the Summer Garden

Planting:

Sow seeds or plant nursery-grown plants in fall (well before the first average frost date) or in early spring after the danger of frost has passed. Most yarrows grown from seed will be inconsistent in height and flower color. If you want a specific color, height or form, buy potted plants.

Soil:

Although yarrow will grow well in just about any type of soil, taller types tend to flop in soils that are rich or overly moist. They are at their best growing in slightly acidic, well-drained soil. “If you have trouble growing yarrow, it’s most likely because your soil is too wet. Plant it on high, dry spots,” recommend Jeff and Marilyn Cox.

In containers:

Compact yarrow varieties thrive in pots with full sun and well-draining soil. Use a gritty potting mix and a container with good drainage.

Water and fertilizer:

Yarrow is one perennial that actually thrives on neglect, and your plants will suffer if you overwater or overfertilize them. Keep the soil evenly moist until the roots become established, but after that only water your plants when the soil is completely dry. Fertilization is rarely needed, and overfertilization can lead to leggy growth.

Dividing:

Yarrow spreads quickly by rhizomes. Divide every 2 to 3 years in spring or fall to avoid overcrowding and to reinvigorate plants that begin to look matted and untidy. (Learn how to divide perennial plants.)

"Yarrow clumps tend to die out in the center after a few years and are best divided regularly to maintain their vigor." — AHS Essential Guide to Perennial Gardening

Pruning:

Deadheading yarrow will encourage repeat blooming and often prolong flowering into fall. If your plants become too tall and lanky, shearing back the foliage will make them bushier and often eliminate the need for staking. To reduce disease problems, thin out plants that become overcrowded and cut out any dead growth.

Staking:

Taller varieties may require staking.

Winter care:

In colder zones, yarrow dies back to the ground in fall. After a hard frost, cut back dead foliage. A light mulch after the ground freezes can help protect roots from freeze-thaw cycles. In warmer regions, the foliage may stay semi-evergreen.

Pests and diseases:

Yarrow generally has few disease and pest problems, but can be prone to powdery mildew and stem rot if planted in shady or wet sites. Yarrow may also be troubled by botrytis (gray mold). Also, keep an eye out for aphids, mealybugs, and spittlebugs.

Does yarrow come back every year?

Yes, yarrow is a hardy perennial that comes back every year. In most climates, it dies back in winter and reemerges in spring, often spreading slightly each season.

How invasive is yarrow?

Yarrow can be mildly invasive in some conditions. It spreads by rhizomes and can form dense mats, especially in loose or sandy soil. Regular dividing and trimming help keep it in check. Opt for sterile or clumping varieties if spread is a concern.

What are the traditional medicinal uses of yarrow?

Yes, yarrow has a long history of medicinal use. Traditionally, it’s been used to help stop bleeding, reduce inflammation, and support digestion. While still valued in herbal medicine today, it’s best to consult a healthcare provider before using yarrow medicinally.