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is yarrow a weed

Yarrow Control: Tips To Remove Yarrow

Yarrow, a perennial plant with feathery leaves that may be both a blessing and a curse in the home landscape, is often called yarrow weed. Ornamental or common yarrow is not native, but Western yarrow is indigenous to North America. Both have a spreading habit and extremely tolerant, hardy natures. It’s the spreading habit that is of most concern to homeowners. Once the plant is in your yard, it’s there to stay and it can be very difficult to remove yarrow.

What is Yarrow?

Yarrow is a low-growing plant that produces flower stalks four times its foliage height. The plant is recognized by the feathery almost fern-like green foliage. Each leaf is between 1 and 6 inches long. Each plant can produce several flower stalks covered by fine hairs.

Flower heads are borne in corymbs or umbrella shaped clusters. Each flower has five colored flowers surrounding 10 to 20 pale yellow florets. The flowers are commonly white or soft pink but now come in yellows, coral and red.

Is Yarrow an Invasive Weed?

The answer to that question is complex but really boils down to opinion. Many people appreciate the easy care nature of yarrow and there are several new cultivars that are introducing new colors and sizes to the home landscape. Yarrow produces season-long umbrella shaped flower clusters that enliven the garden. There are also those who find the plant colonizing entire beds and even the grass. That would classify it as an invasive weed. In these gardener’s minds, yarrow control is paramount.

Yarrow is an extremely adaptable plant. It can grow on any soil and in many conditions. It spreads from its rhizomes. When the plant is disturbed and small piece of rhizome can become a whole new plant. The clustered flowers on their 3-foot tall stocks produce thousands of seeds. The tiny seeds spread by wind and can remain viable in soil for up to nine years. The longevity of the seeds makes complete yarrow control impossible.

How to Remove Yarrow

Killing Yarrow without Chemicals

It’s much nicer to use the term yarrow control but the goal is the same — to eliminate yarrow plants. Digging and hoeing areas where yarrow has spread can remove some of the rhizomes but mechanical control is only effective if it goes down 12 inches and removes every speck of yarrow weed. Providing superior care to the lawn will make it thick and prevent some of the spread of the pest.

Chemical Yarrow Control

There are several chemicals available for killing yarrow. They must be used during the period of growth from spring to autumn. Dicamba, chlorsulfuron, clopyralid, MCPA, triclopyr and 2,4D are all listed as useful for yarrow control by the University of Illinois. Yarrow will require several treatments over the growing season, so it’s best to define the problem early and apply controls as soon as possible. Remember to follow all precautions listed by the chemical manufacturer.

Yarrow is a perennial plant with feathery leaves that may be both a blessing and a curse in the home landscape and often called yarrow weeds. This article will help with controlling yarrow should it become warranted.

Yarrow (achillea millefolium)

Yarrow (achillea millefolium) is a herbaceous, perennial herb. It grows in gardens all over the UK. In a lawn is can form a thick, spreading mat and become an invasive weed.

It has many common names including ornamental yarrow, milfoil, devil’s nettle and thousand-leaf. It has also named soldier’s woundwort in reference to its medicinal effects.

The botanical name of yarrow is achillea millefolium. Achillea is greek and derived from the mythical character, Achilles. It’s written that he carried it with his army to treat wounds. Millefolium means thousand-leaved in Latin, in reference to its fine, divided leaves.

Yarrow is an adaptable and hardy plant. It is native to Europe and western Asia. It was introduced to Australia and New Zealand as a pasture plant. In meadows, the deep roots stabilise and add nutrients to the soil.

It is part of the Asteraceae family of plants, along with dandelions and daisies.

Cultivated forms of Achillea are a common herbaceous garden plants. Sold in garden centres around the country, Achillea adds interest to beds and borders.

Seasons and habitat

Although it is able to grow on any soil, it thrives on dry, sandy lawns which suffer from a lack of nutrition. It is very drought resistant and will out compete grass in hot summers.

It can also tolerate close mowing, so will stay in your lawn all through the main growing season.

How to identify yarrow in your lawn

Achillea millefolium is a very distinctive British lawn weed. The leaves are between 2 and 5 cm long in most lawns, but they can grow up to 15 cm if left undisturbed.

The leaves are green, narrow and are feathery in appearance. On closer inspection you will see that they are very intricate and detailed in nature. The leaves give off a fragrance if rubbed or crushed.

Yarrow flowers between June and October on stalks which are much higher than the foliage. Each plant can produce several flower stalks. The flowers are small and white, cream or pink in colour. They are bourne on umbrella shaped clusters.

The roots of yarrow are thin and fibrous, growing from central nodes of the plants.

Yarrow is very hardy in very dry weather. If you happen to be in a drought or heatwave and you have Yarrow in your lawn, it will stay green long after the grass has browned.

How does yarrow spread?

Yarrow plants vegetativley spread by underground stems. These grow outwards from the main plant and root a new plant a little distance away. If allowed to, yarrow also sets seed. The tiny seeds move on the wind and can remain viable in soil for up to a decade. This makes an established yarrow patch very difficult to erradicate.

Regular mowing keeps it from flowering, reducing the possibility of it spreading.

Cooking and Medicine

Since ancient Greek times, yarrow has had a reputation for healing wounds. It also has other medicinal uses. These include the treatment of fevers, muscular ailments and respiratory complaints.

In the Middle Ages, yarrow was part of a herbal mixture known as gruit used in beer before hops. The flowers and leaves are still used today to add flavour in the making of some liquors and bitters.

Wildlife

The flowers of achillea millefolium provide an excellent source of nectar for bees. It is a food source for many species of moths, beetles and insects. Several species of nesting birds use yarrow to line their nests.

It is a useful companion plant in the garden border. It repels some pest insects while attracting good, predatory ones. So, even if you don’t want it in your lawn, it is very worthwhile to cultivate in your borders.

Toxicity

In rare cases, yarrow can cause allergic skin reactions, so care is advised while weeding. Yarrow is also toxic to dogs, cats, and horses if eaten in large amounts.

Control

Hand weeding may be a possibility if there are only a few plants. Any part of the plant left in the ground may re grow.

Keeping the lawn in a healthy condition will suppress it. Top dressing twice a year and fertilising the lawn is ideal. Also keep the grass well watered during time of dry weather helps.

Chemical control is possible. There are some household weedkillers which will keep it in check. The problem is that the leaves are very thin and tough. Getting the weedkiller into the plant is very difficult. Spray in dry weather and damage the plant before spraying to increase uptake.

Professional weedkillers will have better results. They need to be applied by a lawn care professional and are not available to the public.

An established patch of yarrow may take many years to bring it under control. Seeds laying dormant in the turf will sprout again year after year.

If you have a problem with weeds in your lawn, please don’t hesitate to get in touch.

Yarrow (achillea millefolium) is a herbaceous, perennial herb. It grows in gardens all over the UK. In a lawn is can form a thick, spreading mat and become an invasive weed in a lawn. Yarrow has very fine fern-like leaves and, as a result, is difficult to control in a lawn. Find out more about it and how to control it ]]>