Yarrow is a medium-sized plant in the aster family, making it a relative of such well-known landscape plants as tickseed (Coreopsis) and gerbera daisy (Gerbera jamesonii) and such wild plants as goldenrod (Solidago) and boneset (Eupatorium perfoliatum). Plant yarrow in spring and enjoy it as a long-blooming perennial. It comes in a variety of colors. It is easily identified by its feathery foliage and flattened flower clusters; its foliage releases a pleasant odor when bruised. In addition to being an attractive plant, yarrow has a number of specific uses. It is used in butterfly gardens, as an edging plant, and in rock gardens. It also has medicinal applications (as is indicated by such alternate common names as "woundwort"). Learn how to grow and care for this widely grown flower.
Yarrow is toxic to cats, dogs, and horses. If such animals will be present in your yard, make sure your yarrow is inaccessible to them, so that they don't eat any.
|Common Names||Yarrow, common yarrow, nosebleed plant, sanguinary, milfoil, soldier's woundwort, thousand-leaf, thousand-seal|
|Botanical Name||Achillea millefolium|
|Plant Type||Herbaceous perennial|
|Mature Size||2 to 3 feet tall and wide|
|Sun Exposure||Full sun|
|Soil Type||Well-drained; otherwise tolerant of soil conditions|
|Bloom Time||Summer and fall|
|Flower Color||Purple, white, yellow, pink, orange, red, bi-colored|
|USDA Hardiness Zones||3 to 9|
|Native Area||Asia, Europe, North America|
|Toxicity||Toxic to cats, dogs, and horses|
Yarrow Plant Care
Yarrow thrives across much of the United States except in extreme climates such as deserts and high mountains. A tough plant with a tendency to spread by rhizomes, yarrow may even naturalize in your yard. Before planting one, carefully consider whether it would be all right with you to eventually have multiple yarrow plants in your space.
There are different subspecies and varieties of yarrow that are native across much of the Northern Hemisphere; they usually adapt readily to new homes where they are not native. Sometimes they adapt a little too well: Yarrow plants are considered somewhat invasive. Before planting, you may want to check to be sure that the type you've selected is not an invasive plant that will push out other, local flora.
Yarrow plants have to be staked in some situations, or else you may find the stems flopped down on the ground after high winds.
Provide yarrow with full sun to keep its form compact, to encourage optimal blooming, and to discourage fungal attacks.
Good drainage is all yarrow asks for. It will tolerate clay soil better than many plants, but it grows best with good drainage. It flourishes in multiple soil types and isn't a heavy feeder.
Once established, yarrow is drought-tolerant. Because overwatering can promote the fungal diseases to which yarrow is prone, it is better to err on the side of under-watering the plant in all but the driest of conditions.
Temperature and Humidity
As a plant that can thrive across as wide a swath as zones 3 to 9, yarrow is quite tolerant of weather conditions. It is cold-hardy and can take heat well enough to grow in zone 9. But, south of that, it can succumb to the humidity, being prone to fungal diseases such as powdery mildew that are exacerbated by humid conditions.
Yarrow plants don't require great soil fertility. An annual dose of compost in the spring will invigorate the plant but is not necessary. In fact, if you are worried about it spreading out of control, withhold fertilizer from it altogether.
Types of Yarrow
There are several cultivars of yarrow to choose from; all can be grown in zones 3 to 9:
- 'Apple Blossom': Flowers soft pink to pale rose to purple; 2 to 3 feet tall and wide
- 'Cerise Queen': Deep pink flowers; dark green foliage; 2 feet tall, with a similar or somewhat greater spread
- 'Moonshine': Lemon-yellow flowers; silvery leaves; 18 inches tall x 24 inches wide
- 'New Vintage Red': Bright red flowers; bright green leaves; 10 to 14 inches tall x 10 to 12 inches wide
- 'Paprika': One of the most popular yarrow plants; brick red flowers with yellow centers; 24 inches tall by 30 inches wide
- 'Peachy Seduction': Peach-pink flowers; 23 to 36 inches tall x 18 to 24 inches wide
- 'Red Velvet': Fade-resistant red flowers; 2 to 3 feet tall and wide
- 'Salmon Beauty': Flowers start out salmon-pink and fade to creamy-yellow; 2 to 3 feet tall x 1 to 2 feet wide
As the summer wears on, the plant can start to get leggy (especially in hot, humid climates). If this happens, and if you're content that you've enjoyed enough blooms for a while, cut the plant back to a more compact size. This reduction in plant height will help avoid excessive flopping and the consequent need for staking.
When it comes to propagation, yarrow's tendency to spread (which, in other respects, can be problematic) makes your life easy. After spreading occurs, simply divide your plants (in spring) and make a transplant to the new area you have chosen. For those who either don't want to wait that long or don't want to bother with division, purchase starts at your local garden center (yarrow is widely available).
How to Grow Yarrow From Seed
You can also grow yarrow from seed. Sow the seed indoors in early spring to get a jump on the season (from sowing time to blooming time will take about three months), or, if you don't mind waiting, sow the seed outdoors after all danger of frost has passed and anticipate flowers in fall.
If you choose to sow the seed indoors, here's what you have to do:
- Fill a seeding tray with sterile soilless potting mix or seed starter mix.
- Sow the seeds on top of the mix. Don't cover them with soil.
- Make sure the seeds have good contact with the soil by pressing down on them.
- With a spray bottle of water, mist the mix. The surface of the mix should be moist but not soggy.
- Put the seeding tray in a warm, sunny window until germination occurs (about two weeks).
- Harden off the new plants so that they gradually become accustomed to the outdoors. You can do this by putting the tray outdoors during the daytime hours, and bringing it back indoors at night, for about a week.
- Transplant them to the spot you've selected for them in the garden after danger of frost has passed.
In late fall, when the plant has stopped actively growing, cut it back to its basal (lowest) leaves. This is good garden hygiene since dead foliage would only invite plant diseases. If yarrow is only borderline cold-hardy in your zone, apply a 3-inch layer of mulch around the plant to insulate its roots for winter.
Disease Problems for Yarrow
Yarrow's aromatic leaves discourage animal pests from attacking it for the most part. But this perennial is susceptible to fungal plant diseases.
Stem rot can manifest itself in spots on the bottom part of a plant's stem. The spots can be black, brown, gray, or red. The end result of this fungal disease is root decay and weakened plants that will first wilt, then die back altogether.
Powdery mildew is that light-colored, powdery covering you often see on the leaves of a number of different kinds of plants. It usually starts on the undersides of foliage, making it difficult to detect in time to prevent a full-blown invasion. The good news is that it's rarely fatal. In fact, this fungal disease is not serious enough to warrant spraying.
Fungal diseases like stem rot and powdery mildew are best controlled through prevention:
- Don't water in the late evening: This doesn't give the sunlight a chance to dry the plant's foliage before night falls. The result is that moisture lingers all night, creating optimal conditions for fungal diseases.
- Likewise, avoid irrigating from above. Wetting the leaves invites fungal infestation. Irrigate at ground level.
- Practice sound garden hygiene. Remove diseased plants, rake up leaves that have accumulated around plants, and enhance airflow by spacing plants properly.
- Dividing every other year is a great way to promote good air circulation, thereby cutting down on problems with fungal diseases.
How to Get Yarrow to Bloom
If your plant isn't blooming, rest assured that it isn't due to a lack of fertilization. Yarrow isn't a heavy feeder; it may actually bloom better in poor soil. The effect of fertilizing is usually an increase in foliage and an enhanced tendency to spread. If left alone, yarrow should have no trouble blooming.
As soon as you see your yarrow blooming in the summer, get ready to deadhead it as the flowers fade. This will keep the plant blooming longer.
Are yarrow plants drought-tolerant?
Yes, they are drought-tolerant once established.
Is yarrow deer-resistant?
Yes. Yarrow is a deer-resistant perennial.
Can I use yarrow flowers in floral arrangements?
Yes. With their long, sturdy stems, they make for a good cut flower.