Yarrow (Achillea millefolium) is a popular perennial because it is quite easy to grow since it is hardy and drought tolerant. This plant is quite resistant to pests and attracts beneficial insects, ladybugs and butterflies. There are many varieties of yarrow that you can plant to add colorful flowers to your garden. Flowers bloom with dense clusters in shades of white, pink, red and yellow. This plant blooms the second year. Green leaves are soft, fern-like.
These plants are part of the Asteraceae family (like thistle) and can be grown in USDA zones 3 through 9. Yarrow is native to Europe and Asia and was introduced to the United States during the colonial era. It was used in burial rituals as far back as the time of the Neanderthals, because fossilized pollen was found at the Shanidar burial site in Iraq. Legend says that Achilles of Troy used it to treat his wounded soldiers.
Yarrow has medicinal benefits and it is also used for culinary, artistic, cosmetic and even magical purposes.
How to Propagate Yarrow?
Start yarrow seeds indoors during the winter to plant them outdoors in the spring, once the danger of frost has passed. It is best to do a cold stratification process for a month. These seeds will need light to germinate, so place them by a window or under a growing lamp. Sow seeds with very little potting mix to cover them or none at all. They will germinate in 12 to 28 days.
Covering the seedling tray with plastic wrap to help seeds germinate faster, since they retain the moisture and heat. These seeds need 90% humidity. Remove the plastic wrap once they sprout. Seeds planted outside in the fall will stay dormant until the spring. They will germinate once the soil temperature reaches between 65 to 75 F (18 to 23 C).
Seeds may not replicate the traits of the parent plant. Many types are hybrids of two or more species which can produce seeds with characteristics of several components, not exactly the hybrid they formed.
Yarrow needs to be divided every three years to keep plants healthy. This will prevent the center part from dying. Spring or fall are the ideal times to divide plants. Divided plants will maintain the same traits as the parent plant. Keep the outer portions and discard the middle section. Those that compost can add the leaves to their pile since this plant will speed up decomposition.
Plant tip cuttings in the spring or early summer. Take a sharp knife and cut a stem of soft spring growth off about 6 inches long. Remove the bottom two leaves to keep the stem bare. Place the cutting in a potting medium such as peat moss, perlite or vermiculite. Transplant once the plant roots and new growth is evident.
Yarrow Growing Conditions
These plants prefer full sunlight to grow compact and produce tight flower heads. Partial sunlight will cause their stems to stretch and flop with the wind. Yarrow grows between 2 to 4 feet in height and 1 to 3 feet in width. Give your plants at least 12-24 inches (30-60 centimeters) of space in all directions, as they like to spread out – some people even consider them to be an invasive weed even though they are not aggressive. It can be grown in containers indoors as long as there is enough sunlight.
Soil should be well drained, not too rich in minerals. Loamy soil is preferable, but they can also grow in clay soil as long as it’s not waterlogged. Use a tiller or garden fork to loosen about 12 to 15 inches of soil then mix 2 to 4 inches of compost or herbivore manure. Soil that is too rich will make your plants over grow and require staking. Yarrow can tolerate almost all soil pH from 4 to 8, which ranges from acidic, neutral to alkaline.
Make sure to provide young plants with regular water to help them establish their roots. Once mature, they are quite drought tolerant. Regular fertilization is not needed since these plants are quite low maintenance. This plant is frost tolerant and can survive cold winters.
Yarrow is a good companion plant for plants that are affected by aphids including vegetable crops and citrus trees. They attract beneficial insects such as lacewings and ladybugs that feed on aphids. It is a great plant for borders and rock gardens. The roots of this plant produce secretions that makes nearby plants disease resistant. It also deepens the fragrance, color, and flavor of neighboring plants.
Yarrow Pests and Diseases
This plant is mostly pest and disease free. Powdery mildew and botrytis mold are the few problems it can have. Check leaves for spots or mildew and cut them as soon as you see any infection so that the fungus doesn’t spread. It can be treated with an organic fungicide or neem oil if the problem is too big. Separate plants so they have enough airflow, making them less susceptible to fungus. Make sure the water is not soggy so the roots don’t become infected by soil borne fungi and rot.
They can also be affected by spittlebugs, which look like a little speck of spit on the plant. Hose them off or use organic insecticides to control them.
How to Harvest Yarrow
Plants will bloom late spring to early summer. Some species will continue blooming until fall. Cut the plant after flowering so it produces a second round of flowers. Remove dead foliage and old stems during the fall. This will also help prevent self-sowing. Leaves can be harvested anytime. These plants need regular pruning.
Harvest your plant during summer when flowers are open. Cut the stem half way down. Tie stems in small bunches to dry upside down in a dark, cool place. Store them in a glass jar once they are fully dried. This herb is used to make tea, infusions and poultices both fresh or dried. Make yarrow tea by brewing one or two tablespoons of dried leaves in hot water and allowing it to steep for 10 minutes.
This plant is edible for humans, but toxic to dogs, cats and horses. Young tender leaves can be used raw in salads, steamed like spinach or added to soups and stews. Yarrow leaves were used to flavor beers during the Middle Ages, just like mugwort, until brewers changed to hops. Its flavor is slightly bitter and savory-sweet. And it is said that it can get you more drunk than hops beer.