How and Why to Make Comfrey Tea for Your Garden

What the Heck is Comfrey Tea?

You may have heard talk about comfrey tea. But what,  you ask, is it? And is it for me to drink, or for the garden? The answer: it’s for your garden. But when your garden thrives, it directly benefits you, too. So you could say comfrey tea is both for your garden, and for you. Comfrey tea is a mix of comfrey leaves and stems, and water. The leaves are stuffed into a bucket, which is then filled with water, and covered. You let it sit for approximately two weeks, strain out the leftover vegetative pulp (it will be very, very stinky) , and you have a resulting, nutrient-charged liquid: comfrey tea.

What is Comfrey?

 Common Comfrey (Symphytum officinale) is a large (can grow up to five feet), herbaceous flowering perennial in the borage family. It grows in areas of Europe, Asia and North America. Common Comfrey can become invasive, so for the most part it’s less-assertive, sterile counterpart, Russian Comfrey (Symphytum x uplandicum ‘Bocking 14’) is used in areas of cultivation (like gardens.)  There are a number of comfrey varieties for the smaller urban garden or pots, as well.

Characteristics of Comfrey

1.       It is a dynamic accumulator: Its roots grow deep into the earth:  they can grow 8 feet down into the soil and spread three feet from the plant’s base. These deep roots are its special sauce: by pulling in minerals such as potassium, phosphorous, calcium, iron, magnesium and nitrogen from deep in the soil, the leaves of comfrey become powerhouses of stored, bio-available nutrients.

2.       It’s an attractive plant: It has plentiful, large deep green leaves and clusters of nodding, petite purple flowers. It’s one of the first plants to start its growth spurt in spring and it keeps on growing all the way through late autumn.

3.       It grows quickly: very quickly. One of the reasons comfrey is such an ideal plant for the making of compost tea is due to this fact: you can cut mature-leaved stems a few inches from the base all summer long and it will respond with amazingly fast new growth. This gives you a continuous, reliable source for the making of your tea. Other plants such as clover & alfalfa may have the same nutrient levels as comfrey, but the difference lies in the size and rate of growth of comfrey: you don’t need to cover your garden with it to get its mineral-laden benefits: you need only plant a plant or two.

4.       It biodegrades quickly, too:  It seems comfrey likes to do everything fast. And this is once again a good thing, as leaves packed with nutrients that break down rapidly are ideal for creating not only tea, but also for increasing the health of your compost pile, and as mulch.

5.       It is an absolute pollinator magnet: it attracts bees, predatory wasps and ladybugs—all of which you want in your garden, for both pollination as well as pest control.

6.       Both the rapidly-decomposing leaves & comfrey’s roots appear to increase microbial activity (the processes carried out by microorganisms) and accelerate soil-building (improved soil structure, fertility and health.)

I’ve Made Comfrey Tea: Now What?

First, know that you now have water which has been imbued with all of those nutrients drawn into the leaves from deep in the soil. You have created a very strong, virile concentrate. Like all concentrates, it needs dilution. Without diluting the tea, the concentrate can overpower the plants, leading to sickness or even death of the plant. Diluting the comfrey concentrate with water helps remediate the acidic pH, dilutes the nutrient concentrations to prevent plant burning, minimizes toxins, molds or bacteria, and (something that feels equally important to the gardener) it takes the potent decomposing-vegetation odor down a few notches.—This last may seem trivial but in reality can be significant. The tea will still have a smell, even when diluted. It’s unmistakable. But I promise you your whole garden will not continue to stink. When watered into the soil or sprayed onto the plant leaves the smell will nearly entirely diminish as the soil absorbs the liquid and/or the leaves absorb it. –When I’m working in my garden I do catch a whiff of it now and then, and I know exactly what the smell is. But it’s fleeting, and in my estimation the significant benefits of using comfrey tea in the garden greatly outweight this one slightly smelly factor.

Ratio of Water to Comfrey Concentrate

Generally-speaking, the ideal ratio is 1:10, with one part comfrey tea to 10 parts water.  However, sometimes our tea can be more concentrated and “hot” than other times. If you have made a particularly thick or deep-colored tea, you may need to dilute more.  Similarly, if you lost your patience and didn’t wait the two weeks for your comfrey leaves to do their magic in the water, you may have made weak tea. In that case perhaps you need less then 1:10.  One thing to keep in mind: It’s better to have too weak of a tea than too strong.  Just like when we cut our own hair, when it’s better to go a little easy on the cutting, because you can always cut more, with comfrey tea dilution it’s better to start with 1:10 dilution ratio and risk a slightly weaker tea than using a too-rich tea and burning or killing your plants.

How to Water With Comfrey Tea

·       Water the soil directly around the root zone of the plant.  Watering elsewhere will not reap the same benefits.

·       Alternatively, use the comfrey tea as a foliar spray: instead of watering the soil, spray the plants, for absorption directly through the leaves. Note: In order for foliar sprays to be effective, they need to stay on the leaves and not roll off. This means you need to include a surfactant, such as dish soap, to allow for the tea to remain on the leaves. It doesn’t take much:  just add a few drops of dish soap per gallon of tea.

·       Apply the tea every 1-2 weeks (I use it weekly throughout the growing season)

·       Do not use solely comfrey tea for your garden: our goal is always to nourish and encourage diverse microbial life in the soil. Every few weeks use a different tea—seaweed, fish emulsion, manure tea, compost tea—instead, to keep the soil microbiome thriving.

·       Feed your plants up until 2-3 weeks before full maturation of fruits and vegetables, to prevent nutrient imbalances or damage to the fruit.

There are many who sing comfrey’s praises, and there are good reasons why.  If you’d like to grow one plant that gives you a season-long growth of leaves, that, when submerged in water produce a nutrient-rich concentrate, which you can then dilute and water your plants with….well, that’s hard to argue with. Most nurseries sell comfrey starts—go get one, plant it in sun to part shade, provide water to establish it, and watch it provide and provide.