During the summer of 1984, some friends and I were invited to the cottage of a friend in Muskoka. While there I took advantage of the opportunity to identify plants that were in flower on the property. Two of the plants happened to be herbs that I had studied: yarrow (Achillea millefolium) and St. John’s wort (Hypericum perforatum).
I was ecstatic, as these were important herbs in Western herbalism. We decided to harvest some yarrow and make a big pot of fresh yarrow tea. Upon taking our first sip, just about everyone spit their first mouthful of yarrow tea back into their cup and drank no more. It was strong tasting and very bitter. So as not to waste the tea, and out of respect for the plant, I managed to drink all of the tea in my cup very slowly in small sips over the course of an hour or so.
In the long journey of herbalism that I have tread, yarrow stands out as an herb associated with an important milestones: it was one of the first medicinal plants that I learned to identify and it was probably the first tea that I ever made from an herb that I had harvested myself.
From a medicinal perspective, yarrow is an incredibly versatile herb. It is best known for its ability to heal wounds and lower fever, but its medicine actually covers a much broader spectrum of conditions.
Yarrow is an epithelial herb. This means that it reduces inflammation and heals tissues of the skin and mucus membranes that it comes in direct contact with. On the surface of the body it can be used for wounds, abrasions, bites, and stings, rashes, etc. It is also healing to the blood vessels and can be used for deeper tissue swelling and bruising, as well as varicose veins, hemorrhoids, and other inflammatory conditions of the vascular tissues. For moderate to severe vascular symptoms and traumatic injuries it works best if used internally as well. Yarrow is also one of the better herbs to stop bleeding or oozing of fluid from a wound. It is very antimicrobial and will also help prevent or treat infections after they occur. For all of these applications it can be used in water-based preparations such as a poultice or compress, or in oil-based preparations like infused oils, creams, and ointments.
Similarly, yarrow can be used internally to reduce inflammation and heal conditions of the mucus membranes of the mouth, throat, and digestive tract. It is excellent for mouth ulcers, gingivitis, sore throats, gastric and duodenal ulcers, and other inflammatory conditions. Once more, if there is an infectious component it will help address that as well.
Yarrow is also an excellent herb for treating various kinds of respiratory infections like colds, flu, and sinus infections. It reduces mucus secretions, lowers fever, and boosts immune function. It also directly inhibits viruses. It can therefore be helpful for the treatment of childhood viral infections such as measles and chicken pox. This herb also helps with hay fever symptoms and can be used as a preventive in general immune-stimulating formulations combined with other immune stimulants like purple coneflower (Echinacea spp.).
In the digestive tract, yarrow increases production of digestive secretions, making it useful for both acute and chronic indigestion, gas, and bloating. It also helps reduce congestion of the liver and gallbladder.
As I mentioned previously, yarrow is very healing to the blood vessels. It can be used internally as well as topically for conditions like varicose veins and hemorrhoids, and is also helpful for more serious inflammatory conditions like arteriosclerosis. In addition, it improves peripheral blood flow and can be beneficial for people with poor circulation.
Yarrow is stimulating to the female reproductive system. It can be used to help shorten the menstrual cycle in women with a very long or irregular cycle, or to bring on a period in women whose cycle is suppressed. This also means that when it is being used by women for non-reproductive conditions it should not be combined with other herbs that stimulate the reproductive system, otherwise the combination could bring on a period too early or stimulate heavy bleeding during their period. It also should not be used by women taking oral contraceptives because, although it is extremely rare, there is a possibility that it could stimulate ovulation. This herb should also not be used by pregnant or nursing women, or for infants less than a year old.
As you might have deduced from my story about making yarrow tea, this herb is very strong tasting! In fact, it is relatively strong in general. For that reason it is best used in formulations combined with other herbs. The ideal proportion for yarrow in a formulation is 20-30% – and you won’t want to combine it with other herbs that are significantly bitter tasting.
History and Plant Identification
Yarrow is a circumboreal herb. That means it is native to the temperate regions of the entire northern hemisphere. It has a long history of use in Europe and temperate Asia. When Europeans came to North America they discovered that this familiar herb also grows here and was used by the First Nations peoples. Many of the North American yarrow plants looked slightly different than the common yarrow of Europe and botanists believed they represented a number of separate species. However, they have since discovered that the North American and Eurasian populations of the most common yarrow species have not diverged enough to be considered separate species. Many of what were considered distinct North American species are now classified as different varieties of the same species of common yarrow that occur in Eurasia. A few of the Eurasian varieties have naturalized in parts of North America. Where they occur they can hybridize with our native varieties. It is difficult to tell apart the varieties and their hybrids, but for medicinal purposes it doesn’t matter as their properties are pretty much identical.
Yarrow is a member of the Aster family. Like other members of this family, although it appears to produce single flowers, each “flower” is actually a flower head consisting of multiple flowers. Although there are exceptions, the flower heads of members of the Aster family usually consist of two kinds of flowers. Along the outer edge of the head are the ray flowers that each produces one large ray or petal. Their primary purpose is to attract pollinating insects and in many species they are sterile. In the central portion of the head are many disk flowers that have tiny petals. Collectively the flower heads have the appearance of a single flower. The flower heads of yarrow have three to (usually) five rays, having the appearance of a single flower with three to five petals.
One of the interesting things about the flower heads of the Aster family is that when the disk flowers open, they first open on the periphery of the disk and then open towards the centre. When they first open, the male pollen-producing parts mature. Once they release their pollen the female parts mature in the same flowers. As a result, the open flowers towards the centre of the disk will often be in the male phase while those on the periphery are in the female phase.
When pollinating insects such as bees land on the flower head, they will usually land on the periphery of the disk and take a spiral route towards the centre while they collect the nectar. In this way they deposit pollen from other flowers on the female phase flowers along the periphery before picking up new pollen from the male phase flowers in the centre. This helps to ensure cross-pollination from the pollen of flowers from other plants. However, this might work with a plant with a large flower head like ox-eye daisy (Leucanthemum vulgare), but the flower heads of yarrow are too small to do this. Instead, its flower heads grow in a cluster and open in the centre of the cluster first. As a result, the central heads are more likely to be in the female phase while those on the periphery in the male phase, at least for part of its flowering period. Therefore pollinating insects are more likely to land in the centre of the cluster and spiral their way towards the periphery.
Stalking and Harvesting Wild Yarrow
Yarrow is a plant of open fields and transition areas. The latter are areas that receive direct sunlight for part of the day and are in the shade the rest of the day. Although it can tolerate some shade, yarrow prefers lots of sunlight. It is therefore best to harvest it from open fields. This is particularly true during years when the spring and early summer are cooler and wetter (like this year!). However, during particularly hot and dry years the healthiest plants will be in places where it gets some shade as the soil will have a higher level of moisture in those areas.
In southern, central, and eastern Ontario the usual time that we harvest yarrow is in the last week of June and the first two weeks of July. It could be later than that further north or during cooler years. It is the “herb” or aerial parts of the plant that we harvest and the best time to harvest it is shortly after it goes into flower.
Yarrow produces a relatively flat-topped cluster of many flower heads. As I mentioned above, when it goes into flower the heads in the centre of the cluster open first. Over the period of a day or two they will all open from the centre out towards the periphery. Yarrow is most potent after the flowers have opened, but before they have been fertilized. Since they start getting fertilized fairly quickly, the ideal time to harvest this herb is when about 80-90% of the flower heads in the centre of the cluster have opened and about 10-20% of the heads around the periphery of the cluster are still unopened buds. Although this is a very narrow window, fortunately not all of the plants in a given area will start flowering at the same time, even if they receive the same amount of light each day. In any given area in which this plant is plentiful, the period during which individual plants go into flower will usually extend over two to three weeks, especially if it is growing in an area where plants are receiving different amounts of direct sunlight.
Making Yarrow Medicine
When harvesting yarrow we want a larger proportion of the flower heads than the leaves. It is best to harvest roughly the top 25-30% of the plant. If we dry it to make tea we can use the entire harvested portion. However, my preference is to make a tincture from the fresh herb. The stalk is not as potent as flower heads and leaves. If making a tincture, it is best to cut off the flower heads, strip the leaves from the stalk, and not use the stalk (it makes great compost!).
To make a tincture, you’ll want to use 35-40% grain alcohol. Vodka is 40% alcohol and often used to make tinctures at home. In my clinic I actually use 60% water, 30% alcohol, and 10% glycerin, but some people find this too complicated for personal use. The usually potency is 1:5, which means 1 part yarrow herb to 5 parts liquid. You’ll want to use a wide-mouth jar that is not clear glass; amber glass is best. Although it is not 100% accurate, the simplest way to calculate how much herb to use to make a 1:5 potency tincture is to fill up your jar with water to 1/2 cm from the top and measure the amount of water in millilitres. Divide this amount by six (for the one part herb plus five parts liquid). Whatever you get is the amount of herb that you should use for that jar, but in grams not millilitres. Chop up that amount of fresh yarrow (measured in grams), put it in your jar, and then fill up the jar to 1/2 cm from the top with your water/alcohol or water/alcohol/glycerin solution.
Store it in a dark place, and for the first two weeks shake the jar vigorously once or twice a day. You’ll want it to remain unopened for at least three months before you start using it. Then press and filter it. The simplest way to press it is with a potato ricer and filter it through an unbleached cotton coffee filter. Do not use a paper filter as it is too fine. However, once it has reached the three-month point, it is actually best not to press and filter it until you need to use it. It can keep almost indefinitely if undisturbed but it begins to rapidly degrade after it is pressed and should be used within 6-12 months.