How To Grow and Care for Comfrey

comfrey plant

Quick Overview

Plant Type: Herbaceous perennial
Family: Boraginaceae
Sun Exposure: Full sun to part sun
Watering: Consistent watering
Colors: Purple, pink, cream, white
Size: 12 to 36 inches tall, 9 to 30 inches wide
Hardiness Zones: 4 to 8 (USDA)
Soil Type:
Soil pH: Neutral
Propagation: By root cuttings or crown division.
Toxicity: Toxic to humans and animals

Comfrey, one of my favorite plants, is revered by gardeners for its soil-enhancing abilities and medicinal properties.

When getting your comfrey plants established, they’ll need consistent watering; enough to keep the soil moist, but not soggy. Comfrey will do well in full to partial sun and can tolerate most soils and pH levels.

Comfrey is known to be a powerful tool in your garden. It can act as a regenerative and free source of mulch or be added to your medicine cabinet. Learn more about this wonderful plant to have a thriving garden and a unique medicinal remedy to various ailments.

Comfrey plant

How To Grow Comfrey


Comfrey is a versatile plant worth having in your garden. It is a low-maintenance, high-yield plant. It can be planted in summer, spring, or fall.

Planting in spring is ideal. Comfrey does best in zones 3-9 but will grow just about anywhere.

The easiest and most common way to get comfrey plants started in your garden is from root cuttings. This means you’ll need to find some comfrey that is already established and pull a clump out. Using a shovel to dig out a section is helpful as the roots are strong.

Alternatively, root cuttings can be purchased online.

Comfrey is pretty forgiving, but try to get a section of root that is 3-6 inches long. Each section of root will theoretically turn into one plant, so decide how many plants you want and get at least that many root cuttings. You can get a couple extra to account for any plants that don’t do well.

Next, pick a place to plant them. Comfrey will thrive in full sun but partial shade is okay too, just make sure they will be getting at least 3 hours of sunlight a day.

They tolerate a wide variety of soils, from compact clay to sandy types. They will however thrive best in loamy soil with lots of organic matter. But really, they aren’t picky, so don’t worry if you don’t think your soil is perfect for them, they will grow.

Once you’ve decided where to plant them, lay your root cuttings horizontally in the soil and cover them with 3 inches of soil. Tamp down the soil lightly and give it a good watering. You’ll want to keep the soil evenly moist until you see leaves emerging.

Comfrey plant

Foliage should begin to emerge within 1-4 weeks.

Another way to plant comfrey is to transplant. A young comfrey plant is ideal, one whose leaves are about 2-5 inches tall. Dig up a section of the plant, with root and leaves still intact, and transplant it to your desired area. Place them in a hole deep enough to house the roots comfortably, and make sure the soil line is even or just slightly below where the leaves begin to emerge. Water thoroughly.

The plant will look wilted and sad for up to a week, but trust me, you’ll be delighted (and surprised) by how it bounces back. Just be sure to keep it watered consistently.

It is possible to grow comfrey from seed, but they have been known to take years to germinate, and need to go through a stratification period. Stratification is a fancy way to say they need a winter chilling period before they can be placed in the ground. So while it is possible, it is more work with less of a guarantee for success.

Here’s a quick recap of what you’ve just learned:

  • Comfrey will do best grown from root cutting
  • Plant comfrey in partial to full sun
  • It will grow in most soil conditions
  • Keep it consistently moist while getting established
  • Once established, water when they look wilted
Comfrey plant

How To Care For Comfrey


Among the many things I love about comfrey, one of its best attributes is that it thrives on minimal care.

As a baby plant, it will need constant moisture to get established, but once it’s looking big and happy, you don’t have to worry about your comfrey dying in a dry spell.

I’ve let 2 to 3 weeks pass between waterings for established plants, and they were absolutely fine. If you live in an area that gets to triple digits in the summer ( California anyone?) then you’ll want to check on them every few days. If they look wilted, give them a good soak.

If you live in an area that gets consistent rainfall, you may not need to water them additionally at all.

Comfrey is also known to be relatively disease and pest-free. The occasional slug or snail might munch on a few leaves. For established plants with lots of foliage, this shouldn’t be a problem.

If snails or slugs are eating too much foliage on a baby plant, consider setting beer traps to cut down on their activity.

Comfrey will go dormant in the winter and re-emerge in the spring. Its dormancy will look like it died but don’t worry, it will come back as prolific as ever. You will not need to water it while it’s dormant.

To manage your plants and prevent them from spreading, remove any blooms you see. These blooms will eventually set seed, dispersing potential new plants throughout your garden.

Note that there is a variety, called “Bocking 14”, that produces flowers, but its seed is not viable. That is what makes that variety popular amongst gardeners and landscapers, it may be a good option for you, too.

flowers

Using Comfrey In Your Garden


With its long taproot and sprawling root system, comfrey can draw nutrients from deep in the earth up to its leaves. A good way to get these nutrients spread around your garden is with the leaves. Luckily, comfrey likes to be harvested. It’s recommended that you don’t harvest the foliage until its second season when it’s well established.

You can harvest 70% of the foliage at once, just be sure to leave a handful of leaves so it can continue growing. Or, pick a clump you want to harvest and cut the leaves off close to the base, leaving a few inches. You may be surprised the first time you see that the leaves will fully regrow in a matter of a few weeks.

Depending on the health of the plant, you will be able to harvest the leaves 2-5 times a year.

Use your hands, a shovel, or a strong pair of scissors to break the leaves up a bit. This will kick-start their decomposition process. If you do this by hand, you might want to wear gloves as comfrey can be a skin irritant.

Distribute the leaves throughout your garden, spade them into the soil, or put it around plants or trees that need a pick-me-up. When you put the leaves down as a mulch around your garden, they will decompose. As they do so, they will enrich the soil with their balance of nitrogen, potassium, and phosphorus.

Comfrey will also naturally suppress weed wherever it is planted. Since it grows big and bush-like, one plant can get several feet tall and wide, they naturally shade out weeds. With the lack of sun, weeds will die back.

You can also use comfrey leaves in your compost, or as a layer in your sheet mulch. Comfrey leaves will add nitrogen to your pile, which is essential for good decomposition.

Flowers will develop on your comfrey plant in early summer and be there until your first fall frost. You can expect white or purple flowers, with some varieties producing yellow or pink flowers. These bell-shaped flowers will attract pollinators, which is always good for the garden.

Comfrey plant

Comfrey “Tea”


If you’ve heard of comfrey before, you’ve likely heard of people discussing comfrey tea.

Comfrey tea is a highly concentrated liquid that can be diluted and used as a fertilizer around
the garden.

To make comfrey tea simply fill a five-gallon bucket with comfrey leaves. Fill the bucket with water so that the leaves are completely submerged. Put a lid on it and let it decompose for 3-4 weeks.

Warning: this mixture will reek! That’s why it’s good to keep a lid on during the decomposition process and be prepared when you open it. Once you see that the plant matter has decomposed nicely, strain out the plant matter. You can do this by using a small garden fork to lift the material out of the bucket.

It’s important to remember that this comfrey tea will be highly concentrated and will need to be diluted to at least a 1 to 10 ratio, one part tea, ten parts water.

Once diluted, the solution can last up to a year, but it’s recommended to use it within 6 months. Water plants that look like they could use a nutrient boost with your comfrey tea fertilizer and watch how they perk up!

flowers

Medicinal Uses


Comfrey has been used for thousands of years, across many cultures and parts of the world, as a medicine. Some ailments that may be healed by comfrey include:

  • Inflammation
  • Ulcers
  • Asthma
  • Cuts and Abrasions
  • Burns
  • Joint Pain
  • Bone Fractures
  • Sprains


While there hasn’t been extensive research, many studies can be found that support the idea that comfrey can help with the above-mentioned ailments.

Please note that it is not recommended to ingest comfrey, as it can be harmful to the liver. The FDA and some European countries have banned comfrey products that are intended to be used orally. Most often comfrey is used topically in salves or creams.

The raw foliage can also be applied topically. You can crush the leaves into a pulp-like consistency and apply it directly to a pulled muscle, a bone fracture, or a sprain. One of the names given to comfrey is “bone knit” for its ability to help repair cells, and tissues, thus aiding in the process of healing bones.

flowers

History

The use of comfrey as a healing herb dates back to 400 BC. The word comfrey comes from the Latin word which means “grow together”. This name is appropriate, due to its early uses in Greek and Roman civilizations.

These ancient civilizations used poultices to treat external ailments such as heavy bleeding, wounds, and broken bones. Teas were used for healing internal problems such as bronchial problems and ulcers.

Comfrey plant

Should I Cut Back Comfrey?


Your comfrey plants can get big, about 2-3 feet in width and height, so you may wonder if you should cut it back.

Absolutely get in the habit of cutting back your comfrey plant. Allow it to get established and reach its first flowering. Once you notice that it’s going to flower, go ahead and chop it back. The plant will regrow vigorously. Use the plant matter as a beneficial mulch around your garden.

How Do I Keep It From Spreading?


Comfrey is a very opportunistic plant and has the potential to take over, so it’s understandable to be wondering how you might keep it from spreading.

Avoid tilling near comfrey, which will disperse many pieces of the root around your garden. Also, consider laying down cardboard or a layer of plastic near your comfrey to suppress unwanted growth.

How Can I Get Rid Of Comfrey?


If you decide you don’t want comfrey in a certain part of your garden or yard anymore, you may be asking yourself how to get rid of it.

The best way to eradicate comfrey naturally is to dig it up. Get as much of the root as possible, and dispose of it. You probably won’t get the entire length of the root out since it’s so long, so keep an eye on the area you dug up. If you’re still seeing new growth, place cardboard over it to smother it out, and avoid watering the area for a while.

Comfrey plant

Rooting For Comfrey


Adding comfrey to your garden will bring many benefits.

The leaves of the plant can be used as a natural mulch and fertilizer, the flowers will attract pollinators, and you will have a natural remedy at your fingertips for several common ailments.

With very little maintenance needed and its tolerance to mild drought, you can’t go wrong with adding a few comfrey plants to your garden.