This Sun Worshipping ‘Weed’ Provides Food for Monarch Butterflies and Potent Herbal Medicine for Humans

When we take a walk in the open fields in July in most parts of Ontario, sooner or later we are going to find that the air is filled with a strong sweet aroma that is quite amazing, although it can be overpowering at times. A quick search is likely to turn up some milkweed plants with their large globular clusters of unusually shaped pinkish or yellowish flowers.

There are 11 different of species of milkweed native to Ontario, but common milkweed (Asclepias syriaca) is both the most common and the most aromatic species.

In the fall, this plant has a different kind of beauty. As the aerial parts of the plant begin to die back, the pods open, releasing thousands of seeds that float through the air on their wispy filaments. These filaments are very soft and silky and were once used to stuff pillows.

Milkweed usually grows in open fields as it prefers to get lots of sunlight. It tends to grow in small colonies because it partly spreads by rhizomes. These are underground stems. With herbs that grow this way, the aerial parts are not individual plants, they are the leafy stalks of a single plant that are connected by the rhizomes below the ground.

Milkweed has an interesting history. Its common name comes from the milky latex that exudes from the plant whenever it is damaged. During the Second World War when Japan threatened to control the world’s supply of rubber trees, the latex from milkweed was considered as a possible alternative source of rubber in the west; its botanical name was given to it by Carl Linnaeus, the famous botanist and creator of our earliest system of plant classification. Because of its long history of use as a medicinal plant, the genus was named after Asclepias, the Greek god of medicine. Linnaeus called this species syriaca because he mistakenly believed the plant to have originated in the Middle East. Thus he named it after Syria. In truth, this herb is a native of North America that had been introduced in Europe before Linnaeus’ time.

The young buds, flowers and very young seed pods of milkweed are all edible. Generally, it is necessary to boil them a couple of times and discard the water to reduce their bitterness. I particularly like the seed pods which remind me of a cross between green pepper and okra. The dried stalks were also used as a source of plant fibre for making rope by Native Americans.

The use of this plant is not limited to humans. Milkweed contains some very bitter constituents as well as minute amounts of potentially toxic constituents called cardioactive glycosides. These constituents occur in most members of the Milkweed family, and in even higher quantities in the very closely related Dogbane family. It is likely that these herbs evolved the ability to manufacture cardioactive glycosides as a way of discouraging foraging by insects and mammals. Some insects, however, have developed a tolerance for these constituents and have actually developed the ability to concentrate them in their tissues. This makes them unpalatable and even toxic to many potential predators. Most notable of these is the monarch butterfly. Both the caterpillars and the adults of this species are brightly colored to warn predators that they are not good to eat.


Common milkweed has a long history of use as a medicinal plant. More recently, it has largely fallen into disuse because it has been overshadowed by another more popular species of milkweed, butterfly weed (A. tuberosa), also known as pleurisy root. Butterfly weed has orange flowers that do not grow in globular clusters. It is rare in most parts of southern Ontario, but is a bit more common in eastern and extreme southwestern Ontario, especially in sandy regions.

The milky latex of common milkweed has long been used to treat warts. It must be applied fresh several times per day for several weeks. Eventually the wart will turn black and fall off. The latex from dandelion stems can be used similarly, but milkweed latex is considered superior.

It is primarily the rhizomes of common milkweed that are used medicinally; its properties are considered to be very similar to those of butterfly weed. These underground stems are dug up in October or November, after the aerial parts of the plant have died back. At this time it is still easily recognized by its characteristic pods and the fact that it has a single, unbranched stalk. After digging up and cleaning the rhizomes they can be dried for use in teas, or the fresh root can be tinctured in 40% alcohol.

Common milkweed is an excellent herb for the treatment of lung conditions. It relaxes the bronchioles, reduces spasms and liquefies the mucus secretions of the lungs. It can be used for all manner of lung conditions, from coughs and colds to more serious conditions like bronchitis, asthma, pleurisy and tuberculosis. It is one of the stronger lung herbs that can be used when milder, more tonic herbs are not getting the results that we are looking for.

Milkweed is also a great diaphoretic. It is used to bring on a sweat to help cool down our body during a fever. It can be used for any kind of feverish condition. Its strong diaphoretic properties also make this herb very effective at helping to improve blood circulation to the extremities of the body. Combined with regular exercise it can be used by anyone with poor circulation. In addition, milkweed improves lymphatic drainage. The combination of these properties makes it effective in the treatment of peripheral edema. As a lymphatic it is also helpful for any condition characterized by swollen lymph nodes.

Milkweed has a fairly significant action on the digestive tract. It stimulates general circulation. It is particularly useful for anyone whose stomach is not producing enough enzymes or hydrochloric acid. It is also beneficial for chronic constipation. Its effect on the digestive tract can be somewhat intense for individuals with a sensitive system. Occasionally it will cause nausea or diarrhea. This is very unlikely when it is used as I recommend, below. If these symptoms do occur, reduce the percentage of this herb in your formulation or discontinue its use.

Milkweed is a fairly detoxifying herb. It supports the removal of toxins from the body through its action on the blood and lymphatic circulation, the kidneys, digestive tract, and, to a lesser extent, the liver. In this capacity it is primarily used in the treatment of rheumatoid arthritis.


As I mentioned earlier, milkweed contains small amounts of chemical constituents called cardioactive glycosides. These constituents can have a strong stimulating effect on the heart. In the case of this herb, these constituents are in very low concentration and of a variety that is less toxic than stronger heart stimulants such as foxglove. Nevertheless, the presence of these constituents requires a number of restrictions on the use of this herb.

First of all, common milkweed is a medium potency herb. It therefore should only be used in combination with other herbs. I recommend that it only comprise up to 25% of a formulation and its use be limited to two to three month periods.

Due to its potency and the presence of cardioactive glycosides, this herb should not be used during pregnancy, by nursing mothers, children under three, or seniors. It also should not be used by anyone with high blood pressure or a heart condition except under the supervision of a qualified practitioner.

Milkweed is also contraindicated for anyone taking blood pressure or heart medications or MAO inhibiting drugs.

If we follow these restrictions, milkweed is a very safe and effective herb. However, as every individual is different, there is always the possibility that someone could have a rare idiosyncratic reaction to the herb. This is possible with any herb. Therefore, if you are using milkweed or any herb and you have any unusual reactions, discontinue it immediately and consult with an herbalist or other qualified natural health practitioner. In most cases it will probably be nothing more than some kind of detox reaction, but it is better to rest on the side of caution.

It’s amazing how herbal trends come and go. In naming the milkweeds after the Greek god of medicine, Linnaeus was acknowledging their importance as medicinal herbs. Yet today, milkweed is barely mentioned in herbal texts. This is partly due to the fact that it’s easier for companies to market something that is foreign and exotic: “the grass is always greener…”

The most amazing thing is that Nature has provided for all of our medicinal needs no matter where we live on this Earth. All we need to do is look in our own backyard.

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  1. Liz
    March 13, 19:26 Liz

    Enjoyed your article about milkweed. I am an Akashic Record Practitioner and in doing a reading for a woman with Ovarian Cancer (1st time) I got the words Milk Pod. The Pod holds the seeds, am I not correct? Tried to find more info and a place to buy seeds and how they are taken in by the body and if they are safe and was only able to find milkweed.
    Can you tell me if Milk Pod seeds are used for Ovarian Cancer, and if so where does one buy them, and are they safe to ingest?

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