Achillea, or yarrow, is one of the most commonly grown garden flowers. Yarrow are very rugged and adaptable plants that grow well in USDA Hardiness zones 3 - 9. It is aNorth American native plant. The cultivated varieties have become staples in gardens around the world, because of their tough nature, ease of growing, and beautiful flowers and foliage.
There are about 85 species of yarrow. Most of the garden selections have ferny, often feathery foliage and flat umbel flowers, although some, such as ‘The Pearl’, have small button-like blossoms and others have flowers resembling daisies.
With their sprays of soft, feathery, aromatic foliage and their tendency to stay in tidy clumps, yarrow plants make great filler plants and edgers.
Contact with the foliage can cause skin irritation in some people.
The size of the Achillea plants will depend on the variety you are growing and your growing conditions.
In general expect plants to grow:
- Height: 6 - 36 inches
- Spread: 12 - 24 inches
Yarrow plants love heat and sunshine, so give them a spot where they will receive full sun. If they do not get enough sun, the plants will be leggy and flop over.
Yarrow blooms repeatedly throughout summer. For the most blooms, keep the plants deadheaded. Don't be hesitant about lopping off the spent flowers, they will set more buds quickly if you do.
Using Yarrow in Your Garden Design
The flat flowers and soft foliage contrast nicely with spiky plants like liatris, penstemon, and Veronica. Yarrow plants are great in the mid-border, where they will add season-long color if planted in large clumps. Since they can take heat, drought, and even poor soil, they are a natural choice for difficult areas.
Although they have been coming out with many new colors, the excellent soft yellow yarrows, like 'Moonshine' brighten up blue flowers and flowers with darker tones in the garden.
Yarrow makes an excellent cut or dried flower.
Suggested Achillea Varieties
New Achillea varieties are introduced every year, but three that have survived the test of time are:
- Achillea millefolium ‘Paprika’ - Dark orange-red flowers that deepen with age.
- Achillea ‘Coronation Gold’ - Extremely adaptable and hardy.
- Achillea ‘Moonshine’ - Soft yellow blends well with other colors
Achillea Growing Tips
Soil: Yarrow is tolerant of most growing conditions, including a wide span of soil pH, but it really does best in a well-draining soil. If your soil retains water, consider adding organic matter to it before planting, to improve the drainage.
Planting: You can start yarrow from seed indoors or out. To get a head start, start seed indoors 8 - 10 weeks before your last frost date. Just sprinkle the seeds on the surface and gently press them down. Don't cover with soil; yarrow needs light to germinate. The seed will germinate faster if it is kept warm. You could use a heating mat under the seed tray or put the whole thing in a plastic bag until the seeds germinate. Be sure to keep the soil moist.
You can also direct sow yarrow in the garden, at any time of year. Sowing in late summer will give you plants that are in their second season, the following year, and ready to flower.
And of course, you can start with plants. Yarrow plants are easy to find in most garden centers. Named varieties, especially the newer one, will be more expensive, but there are plenty of more common varieties available at very reasonable prices.
The best time to plant is in the spring, to take advantage of the cooler temperatures and rain which will help the plants become established. But yarrow is a tough customer and can be planted or moved at any time, as long as you give it some extra water while it gets established.
No special planting instructions are needed. Just make sure the plant is at the same depth in the ground as it was in the pot.
Caring for Yarrow Plants
Yarrow plants are very low maintenance. They are drought tolerant and don't need supplemental feeding unless your soil is very poor. An annual side-dressing with compost should be enough.
For near continual bloom, deadhead regularly. Plants can become tired looking by mid-season. Shearing back the foliage with refresh the plants and keep them full and bushy, so you shouldn't need to stake them.
In ideal growing conditions, yarrow can spread rapidly, although not aggressively. Divide every 2 - 3 years, as needed.
Pests and Problems of Achillea Plants:
Very few problems plague yarrow plants. It is rare to see any insect damage. The most common problem is fungal diseases of the leaves. Allowing for good air circulation can prevent this.