Comfrey is the common name for plants in the genus Symphytum, which are considered important herbs for use in organic gardening. It’s grown in parts of Europe, Asia and North America, producing clusters of blue, purple and white flowers. It may best be known, however, for its slender, long leaves and black-skinned roots.
The root and leaves of the plant have been used in traditional medicine for many years in areas around the world. For example, in Japan, it was a traditional treatment referred to as “knitbone,” and harvested for more than 2,000 years to help ease joint inflammation and to heal burns, bruises and muscle sprains. Europeans have long used it for treating inflammatory conditions like arthritis and gout. One of the reasons it’s likely to be so effective is that it contains chemical compounds known as allantoin and rosmarinic acid. Rosmarinic acid helps to soothe pain and reduce inflammation, while allantoin helps boost the growth of new cells.
People still use comfrey as a medicinal remedy today, and it’s also quite useful for maintaining permaculture systems.
Something important to keep in mind, however, is that comfrey is toxic to the liver for humans as well as livestock, which means it should never be taken orally or used on open wounds. Some have recommended it as a livestock feed supplement, but for obvious reasons, that’s a very bad idea. It was previously used in its tea form to help treat stomach issues like diarrhea and ulcers, as well as menstrual cramps, persistent coughs, chest pain and even cancer – but experts raised the red flag on it, stating that it contains toxic substances known as pyrrolizidine alkaloids, or PAs, which damage the liver and can lead to fatality. A number of countries, including the U.S., have banned the sale of comfrey-containing oral products.
Still, comfrey offers many other uses, both topically and in the garden. It is very easy to grow, and because the foliage is at its best if cut before blooming time, you don’t even have to wait for the flowers to harvest it. It reaches heights of over two feet and spreads to more than a yard across, but as it doesn’t throw out creeping roots and hardly ever sets seed, it’s remarkably non-invasive.
One of the best ways to take advantage of comfrey’s benefits, which we’ll discuss more in-depth a bit later, is to grow it yourself. It can be planted spring, summer or fall – anytime the soil can be worked, and in the warm, southern regions of the U.S. it can be planted and harvested year-round. All you really have to do is grow it, sit back awhile and then reap the rewards.
While comfrey prefers a soil with a pH of 6.0 to 7.0 and does best in rich, moist soil in full sun, it will tolerate some shade and can be grown virtually anywhere, wet or dry. It tends to adapt quite well to just about any environment, and will even thrive in drought where most other plants would wither and die.
When starting multiple comfrey plants, it’s more common to use root cuttings. These are 2- to 6-inch lengths of root which are planted horizontally 2- to 8-inches deep. If you have more sandy soil, plant it deeper. For clay shallow, stick to the shallow end. Space them in a grade, about three feet apart.
Once comfrey is established, it will generally take care of itself, although regularly watering will allow it to thrive, keeping it strong and blooming. Every year the plant will get a little larger and the root system will get more dense – once established, it’s very hard to get rid of and can actually live for several decades before it begins to decline. The plants are very hearty, they can tolerate drought and there are no insects known to be a problem for comfrey either. Even disease is rare – while there is a comfrey rust that can overwinter in roots and reduce yield, it’s rather uncommon in most areas.
The leaves can be harvested and dried anytime, generally, you can make your first cutting when the plants reach around two feet in height. If you harvest early, you won’t get any flowers. Some gardeners advise not to harvest the first year and cutting off any flower stalks that for in order for the plants to establish a good, strong root system.
Now that you have your own comfrey at your fingertips, you’ll find a multitude of ways to use it.
Comfrey leaves can be used to help activate compost heap as they’re high in nitrogen, making them an outstanding bioactivator. If you have a large amount of fall leaves or other dried brown material, layering it with comfrey leaves is a good way to help balance the carbon-to-nitrogen ratio and jumpstart decomposition.
To do so, gather your comfrey leaves and crush them, using garden scissors will help you cut through them quicker. Add a little bit of water, and then crush them for another minute to two to make a paste. Add more water to liquify, and then simply pour it all onto your compost pile – it’s kind of like the way our digestive system works. Chewing up food is an extra step that helps the process. The “pre-digestions” helps beneficial micro-organisms in the compost pile get to work quicker and more efficiently. The result is compost with a higher nutrient content.
Young perennials, such as berry bushes, fruit trees, asparagus, herbs, etc., and fruiting vegetable seedlings like squash, cucumbers, tomatoes and peppers, can get a great nutritional kickstart from comfrey. When you plant, simply bury a few of the leaves underneath each planting spot. As they decompose, they’ll provide essential nutrients to help your young plants grow nice and strong.
You can make a compost tea to provide an instant nutrient boost to your established plants too. It’s made by steeping the fresh comfrey plant matter in water, straining the liquid and then using it to water any plants that may need a mid-season boost of nutrition, or those that are looking stressed. The extra nitrogen in your comfrey compost tea will help to encourage better flowering and more vigorous growth in all sorts of plants.
To make it, fill a container of any size about halfway with fresh comfrey leaves. Add water to fill to the top, cover and allow it to steep for three to six weeks. Fair warning, you may want to hold your nose when you’re near it as the smell is anything but pleasant. Strain off the liquid using your other hand, and then dilute it by half. You can make a less smelly, weaker tea by adding a gallon of water to every quart of fresh comfrey leaves and then allow the mixture to sit for three days, stirring every day. Afterward, strain and use it at full strength.
Buying comfrey oil can be pricey, but if you have your own plants growing at home, you can save a lot of money while taking advantage of its many different uses. To do so, you’ll want to use the freshest dried herbs. Both the roots and leaves are used for this purpose – to harvest and dry the leaves, pick them, gently wipe the dirt off with a towel and allow them to dry whole overnight. To get your comfrey root, dig it out when the weather is dry, and then clean them by hand, brushing the dirt off the root gently. Chop it up finely and then lay it out on a paper bag overnight.
Follow this recipe to make your comfrey oil.
Your roots should already be chopped up, but if they’re not, do so now and then break up the leaves by hand. Place everything into a 16-ounce glass jar and then cover it all up with your olive oil. Place the lid on the jar tightly and shake. Now allow it to steep for 28 days. After that period, strain out the oil by using a clean old shirt lined in a strainer, and then pour the mix through it into a bowl. Squeeze the shirt with the herbs in it. The strained liquid becomes your comfrey oil, which you can store, preferably in a dark-colored glass bottle.
You can either rub the raw comfrey leaves onto poison ivy blisters, or use the oil in the same way – just remember not to apply it to broken skin.
If you have a wound, once it’s begun to heal and is no longer open, you can use comfrey to prevent scar tissue from forming around it, and to help speed up the rest of its recovery. Crush up the leaves and rub them onto the area, and dab a little comfrey oil onto it.
Comfrey is especially effective for treating skin rashes, which is why comfrey creams, balms and salves have been around for centuries. In fact, the name comfrey actually means “to grow together,” highly appropriate for a plant well-known to heal wounds. Once again, this remedy should only be used when the skin is not broken. If you have a body rash, you may want to use it in a bath by filling up a muslin bag with the dried or fresh leaves and enjoying a good soak. It will not only help to support the health and beauty of your skin, it will help soothe the itch of a rash. You can also use the oil, or rubbed the crushed leaves onto the affected area to help it heal faster.
If you have an infection, and/or are experiencing pain and inflammation, using a poultice is a good way to go when you don’t want to apply the oil directly. Simply mix four cups of chopped comfrey leaves and stems with a quarter cup of carrier oil like olive oil or almond oil. Don’t strain out the herb, but instead, wrap the comfrey oil paste using a cotton cloth. Freeze it and then apply to affected areas to reduce inflammation, swelling and pain, holding it on for at least 30 minutes for best results.
Many of us come home after a long day with tired, sore feet, but you can use comfrey to create an herbal foot bath that will help re-energize and soothe them. Here’s how to do it.
Applying comfrey oil or the leaves rubbed against the affected area of a fracture or torn muscle is also said to promote faster healing and has been used for this purpose for hundreds of years.