How to Grow, Harvest & Dry Comfrey
If you're looking for an herb that can produce an impressive amount of plant material year after year, comfrey deserves consideration.
Comfrey is a vigorous perennial with large leaves, bell-shaped flowers, and a substantial root system. Once established, a healthy plant can provide multiple harvests throughout the growing season.
Herbalists value comfrey for traditional topical preparations, while gardeners often grow it for mulch, compost, and other garden uses.
There's just one thing to know before you plant it:
Choose your location carefully. Comfrey may be there for a very long time!
Here's how to grow, harvest, dry, and store comfrey for your garden and home apothecary.
What Is Comfrey?
Comfrey belongs to the Symphytum genus and the borage family, Boraginaceae.
Common comfrey is:
Symphytum officinale
You may also encounter Russian comfrey:
Symphytum × uplandicum
Comfrey is a perennial, meaning it can return from its roots year after year.
The plant develops:
- Large, hairy leaves
- Thick stems
- Deep, substantial roots
- Clusters of bell-shaped flowers
Depending on the type, flowers may be cream, pink, purple, or blue-purple.
Is Comfrey Easy to Grow?
Very.
In fact, your bigger problem may eventually be figuring out how to stop it from growing where you don't want it.
Once established, comfrey is generally a tough plant.
It typically prefers:
- Full sun to partial shade
- Reasonably fertile soil
- Adequate moisture
- Well-drained growing conditions
Established plants can become quite large, so give them room.
The Most Important Decision: Where to Plant Comfrey
Before you plant comfrey, think about where you want it five years from now.
This isn't necessarily a plant you casually move around every spring.
Comfrey develops a substantial root system, and pieces of root left in the ground may produce new plants.
Trying to dig out an established comfrey plant can therefore become frustrating.
You remove the plant.
A root fragment remains.
And up comes another comfrey plant.
For this reason, consider placing it somewhere permanent, such as:
- Along the edge of an herb garden
- Near a compost area
- In a dedicated medicinal-herb bed
- Along the edge of a homestead garden
- Somewhere it has room to remain long-term
Don't put it somewhere you'll regret later.
Comfrey From Seed vs. Root Cuttings
Depending on the type of comfrey you're growing, plants may be started from seed, root cuttings, or crown divisions.
Root cuttings are particularly effective because comfrey readily regrows from pieces of root.
Some cultivated Russian comfrey varieties are sterile or produce little viable seed and are primarily propagated through root or crown divisions.
If you're buying comfrey specifically for your herbal garden, find out exactly which species or cultivar you're purchasing.
How Much Sun Does Comfrey Need?
Comfrey generally grows well in full sun to partial shade.
Plants receiving plenty of sunlight can produce substantial leafy growth.
In very hot conditions, some afternoon shade may be beneficial.
Like most herbs, its exact performance will depend on your climate, soil, rainfall, and growing conditions.
How Much Space Does Comfrey Need?
Give it room.
A mature comfrey plant can develop into a substantial clump with large leaves spreading outward from the crown.
Spacing plants several feet apart can improve airflow and give you easier access for harvesting.
If you're creating a dedicated comfrey patch, remember that those relatively small plants you're putting in the ground today won't stay small.
Does Comfrey Need Fertilizer?
One of the reasons gardeners love comfrey is that established plants can produce significant biomass.
Good soil and organic matter can encourage vigorous growth, but comfrey generally isn't known as an especially delicate or demanding garden plant.
Adding compost around established plants can help support growth.
And interestingly, the comfrey itself can eventually contribute organic matter back to your garden.
When Can You Harvest Comfrey Leaves?
Allow young plants time to establish before aggressively harvesting them.
Once you have a healthy, mature plant, you can typically harvest leaves more than once during the growing season.
Choose leaves that are:
- Healthy
- Vibrant
- Free from disease
- Relatively clean
- Free from excessive insect damage
For herbal preparations, make sure you know the species you're harvesting and that the plant hasn't been exposed to herbicides, pesticides, or other unwanted chemicals.
How to Harvest Comfrey Leaves
Comfrey leaves can be somewhat coarse and hairy, so gloves can make harvesting more comfortable.
You'll need:
- Garden gloves
- Clean garden shears or pruners
- Basket or breathable container
Cut healthy leaves with clean shears.
If you're harvesting from a mature, vigorous plant, you can collect a substantial amount while leaving the crown and root system intact.
The plant can then produce additional foliage.
Don't Harvest Every Leaf From a Young Plant
It's tempting.
You finally have comfrey growing and immediately want to fill the drying rack.
Give young plants a chance to develop a strong root system first.
Once the plant is well established, it can tolerate much heavier harvesting.
A little patience during the first season can give you a much more productive plant later.
Should You Wash Comfrey Before Drying?
If you're harvesting from your own clean, untreated garden, you may simply inspect the leaves and remove visible debris.
If washing is necessary, rinse the leaves and remove as much surface moisture as possible before drying.
Excess water slows the drying process.
The most important thing is that the leaves become completely dry before storage.
How to Dry Comfrey Leaves
Comfrey leaves are large and contain plenty of moisture.
Good airflow is important.
Method #1: Drying Screens
Arrange leaves in a single layer on herb-drying screens.
Don't pile wet or fresh leaves on top of one another.
Place the screens somewhere:
- Warm
- Dry
- Well ventilated
- Away from strong direct sunlight
Turn the leaves periodically to encourage even drying.
Method #2: Hanging Drying Rack
A mesh hanging herb dryer works well if you're harvesting large amounts of comfrey.
Spread the leaves loosely across the shelves so air can circulate around them.
This is particularly convenient if you plan to harvest comfrey several times throughout the summer.
Method #3: Food Dehydrator
A dehydrator can be especially useful during humid weather.
Arrange leaves on the trays without overcrowding them.
Use a low temperature appropriate for drying herbs according to your dehydrator manufacturer's instructions.
The goal is to remove moisture rather than cook the leaves.
How Do You Know When Comfrey Is Completely Dry?
Don't judge only by the thin edges of the leaf.
The thicker central veins and stems may retain moisture longer.
Properly dried comfrey should feel:
Dry, crisp, and brittle rather than soft and flexible.
Check the thickest areas carefully before putting the herb into a sealed container.
If you're unsure, let it dry longer.
A little extra drying time is preferable to storing damp herbs and discovering mold later.
How to Store Dried Comfrey
Once completely dry, transfer your comfrey into an airtight container.
Glass jars work well.
Label the container immediately.
I recommend including:
Comfrey Leaf
Symphytum officinale
Harvest Date
FOR EXTERNAL USE ONLY
Store your dried herb somewhere:
- Cool
- Dark
- Dry
Keeping the plant part and botanical name on the label is particularly helpful with comfrey because different Symphytum species and plant parts can have different chemical profiles.
Why Label Comfrey "For External Use Only"?
Comfrey contains naturally occurring compounds called pyrrolizidine alkaloids, or PAs.
Certain PAs are associated with serious liver toxicity when consumed.
Although older herbal traditions sometimes used comfrey internally, modern safety guidance generally discourages internal comfrey preparations.
Labeling your dried comfrey clearly helps prevent someone from accidentally grabbing the jar and making tea from it.
That's especially important if your apothecary contains many jars of dried green leaves.
How to Harvest Comfrey Root
Comfrey root has also historically been used in topical herbal preparations.
Roots are generally harvested by digging around an established plant and removing root material.
But remember:
Comfrey can regenerate from root pieces.
If pieces remain in the soil, you may end up with new growth.
That's useful if you're propagating comfrey.
It's considerably less useful if you're trying to remove it.
Comfrey root also deserves additional attention because PA concentrations and other constituents can differ between the root and leaves.
Learn more in:
Comfrey Leaf vs. Comfrey Root: What's the Difference?
Can You Divide Comfrey?
Yes.
Established comfrey can be propagated using root pieces or crown divisions.
This makes it relatively easy to expand your patch—or share plants with another gardener.
Just make sure the recipient knows what they're getting.
Giving someone comfrey without mentioning how persistent it can be is a little like giving them a puppy and forgetting to mention that it's going to become a Great Dane.
It's a wonderful plant.
It just deserves an intentional home.
What Can Gardeners Do With All Those Comfrey Leaves?
Here's where comfrey becomes especially interesting.
Not every leaf needs to go into your apothecary.
Comfrey produces so much biomass that gardeners often use excess leaves in other ways.
Add Comfrey to Compost
Comfrey leaves can be added to a compost pile along with other green and brown materials.
They break down and become part of your finished compost.
Use Comfrey as Mulch
Cut leaves can be placed around appropriate established plants as organic mulch.
As the material decomposes, it contributes organic matter to the soil.
Keep mulch positioned appropriately around plants rather than piling wet plant material directly against vulnerable stems or crowns.
Chop and Drop
Some gardeners simply cut comfrey leaves, chop them into smaller pieces, and leave them around garden plants to decompose.
This practice is often called chop and drop.
It's an easy way to return plant material to the garden without carrying everything to the compost pile.
What About Comfrey Fertilizer Tea?
You'll often see gardeners make a strong liquid plant feed by soaking comfrey leaves in water and allowing them to decompose.
And fair warning:
It can smell terrible.
This isn't an herbal tea for people.
It's a decomposed plant mixture intended for garden use.
If you experiment with homemade garden fertilizers, research appropriate dilution and application methods for the plants you're growing.
Does Comfrey "Mine" Nutrients From Deep Soil?
You'll frequently see claims that comfrey is a dynamic accumulator that uses its deep roots to pull extraordinary quantities of minerals from deep in the soil.
The idea has become extremely popular in permaculture circles.
Comfrey certainly produces abundant mineral-containing biomass, and returning those leaves to the soil can recycle nutrients already taken up by the plant.
However, some of the more dramatic claims about "mining" specific nutrients from deep soil are repeated more confidently online than the available evidence necessarily supports.
You don't need the exaggerated version to appreciate comfrey.
It produces lots of useful organic material. That's valuable all by itself.
Let Some Comfrey Flower
If you're growing comfrey, consider allowing at least some of it to bloom.
The clusters of bell-shaped flowers can attract visiting pollinators.
Watching bees work a patch of flowering comfrey is another reason this plant can be a lovely addition to a diverse garden.
Depending on the type you're growing, flowering may or may not result in viable seed.
From Garden to Apothecary
Once you've successfully dried your comfrey leaves, you have material ready for future topical herbal projects.
One of the easiest is:
Comfrey Infused Oil
Dried leaves can be infused into a carrier oil such as olive or sunflower oil.
That oil can then become an ingredient in:
- Comfrey salve
- Herbal balms
- Massage oils
- Calendula + comfrey salve
- Other topical herbal formulations
Read the complete guide:
How to Make Comfrey Infused Oil for Salves & Balms
A Productive Herb Worth Giving Permanent Space
Comfrey isn't a delicate herb that needs constant attention.
Once established, it can become one of the most productive plants in an herbal garden.
You can harvest the leaves.
Dry some for your apothecary.
Use others in the compost.
Mulch with them.
Let the flowers feed visiting pollinators.
Then watch the plant grow back and do it all again.
Just remember the first rule of growing comfrey:
Plant it where you're happy to have comfrey for a very long time.
Do that, and this old-fashioned herb can become a useful part of both your garden and your home apothecary for years.
Explore the Complete Comfrey Series
This article completes our 5-part Comfrey Herb Guide Series:
- Comfrey Benefits & Uses: A Beginner's Guide to This Traditional Herb
- Comfrey Salve: Traditional Uses & Why Herbalists Keep It in the Apothecary
- Comfrey Leaf vs. Comfrey Root: What's the Difference?
- How to Make Comfrey Infused Oil for Salves & Balms
- How to Grow, Harvest & Dry Comfrey
Explore Related Products
Interested in incorporating COMFREY into your daily routine? Explore our collection of handcrafted products inspired by traditional herbal practices and natural living. From soothing herbal teas to botanical body care, each product
Recommended Products & Resources
Growing your herbal knowledge is one of the best investments you can make. Whether you're planting your first herb garden, learning how to preserve your harvest, or exploring traditional herbal practices, these books and tools can help you continue your journey.
As an Amazon Associate, we may earn from qualifying purchases.
Explore More About Comfrey
Explore More Herbs
Continue building your herbal knowledge with these popular wellness guides:
This information is provided for educational purposes only. Comfrey contains pyrrolizidine alkaloids associated with liver toxicity when consumed. The herbal preparations discussed in this series are intended for appropriate external use. Always positively identify plants before harvesting and follow appropriate safety practices.