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How To Make Comfrey Fertilizer

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As a gardener, we all would love to be able to produce our own fertilizers at home. One of the easiest ways to do this is to make fertilizer with comfrey. Making Comfrey fertilizer will allow the gardener to take control of the feeding of their plants naturally and organically.

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    To make comfrey fertilizer you will need to follow the tips below.

    • Grow comfrey in your garden to harvest
    • Harvest the comfrey and collect in a bucket
    • Fill the bucket with water to barely cover the comfrey
    • Place lid on the bucket and put behind the shed
    • Allow 4 to 6 weeks to steep before use.

    Although the above tips are basic in this blog post we will cover comfrey in much more detail and show you two processes to make comfrey fertilizer.

    Two methods to make comfrey fertilizer

    • Comfrey fertilizer made with water
    • Concentrated comfrey fertilizer without water
    HOW to make COMFREY fertilizer At H...
    HOW to make COMFREY fertilizer At Home- The Very BEST Way!

    There are two real methods to make Comfrey fertilizer, known as Comfrey tea, and each has a totally different process to make, and both have different duration in the time taken to make.

    Comfrey Fertilizer Made With Water

    Above I gave a very basic breakdown of the process for making comfrey in water. Otherwise known as comfrey tea. This is very basic and straightforward to make. If you can make a cup of tea you can make this. Just steep the leaves for a long time. The resulting liquid will become your comfrey fertilizer. You will need to water this down 10/1 when feeding your plants.

    Concentrated Comfrey Fertilizer

    Making concentrated Comfrey fertilizer is a much longer process. However, It is a much better product to produce. The reason for this is because It takes up much less space than the first process. It produces a dark black sticky syrupy liquid that is very concentrated and you will only need around 10ml per liter then add it to a watering can.

    This process also has a few other benefits. It is much easier to store due to the concentration and the product lasts longer and doesn’t smell like steeping comfrey in the first process.

    To make this concentrated comfrey fertilizer you need to make a comfrey pipe. Leaves are placed into this pipe and a weight is placed above. The leaves then are left to decompose naturally and the resulting liquid is collected in a vessel below.

    If you would like to learn more about both of these methods and how to build a comfrey pipe, check out the video below where I take you through it step by step.

    Why is comfrey good as a fertilizer?

    Comfrey is so good as a fertilizer because it belongs to a group of plants called accumulators. These plants send down very deep taproots and pull up nutrients from deep in the ground that most plant species cannot reach. The plant then stores this in its tuberous root system and pushes it out through its leaves.

    Comfrey has a fantastic NPK ratio. NPK for those who don’t know stands for Nitrogen, Phosphorus, and Potassium. These three nutrients are very important in plants’ health along with calcium. It must be noted they are not the only nutrients required by plants.

    Having more NPK than even farmyard manure it is no wonder why so many gardeners are looking into making their own fertilizer at home using Comfrey. It is totally organic, and more importantly FREE.

    Can I use any Species of Comfrey as fertilizer?

    All varieties of Comfrey can be used in this way. They are all accumulators and will provide you with the nutrition your plants require in the garden. However, not all Comfrey is identical. Some are invasive and others are not. So it is important to understand which variety you have or wish to purchase.

    What is the species of Comfrey can I use for fertilizer that is not evasive?

    There are around 35 known species of comfrey as you can see from the chart below. However, only one cultivar that is not invasive, but more on that later.

    • Symphytum asperum – prickly comfrey, rough comfrey
    • Symphytum bulbosum – bulbous comfrey
    • Symphytum caucasicum – Caucasian comfrey
    • Symphytum ibericum – creeping comfrey,
    • Symphytum officinale – comfrey
    • Symphytum orientale – white comfrey
    • Symphytum tauricum – Crimean comfrey
    • Symphytum tuberosum – tuberous comfrey
    • Symphytum × uplandicum – Russian comfrey, healing herb

    So as mentioned there is only one cultivar which is Symphytum x uplandicum this is Russian comfrey classified as Bocking 14. I grow Bocking 14 at home. Bocking 14 cannot become invasive due to it being sterile. The only way to propagate Bocking 14 is by root division.

    What nutrients does comfrey fertilizer have?

    • Nitrogen
    • Phosphorus
    • Potassium
    • Calcium
    • Manganese

    The 5 nutrients are the main nutrients that Comfrey carries and transfers into Comfrey fertilizer. It has huge amounts of calcium, this is particularly useful in stopping blossom end rot (BER) in tomatoes, eggplants, and peppers.

    Along with these 5 main nutrients, Comfrey also accumulates micronutrients beneficial to plants as well as B12 so this really is a perfect plant to grow in the garden

    How long does Comfrey fertilizer last when stored?

    If you make the concentrated fertilizer it will last for around a year. So you could make one large batch and store it until it is required. If making Comfrey fertilizer with water then this should be used as soon as it is ready. It will, however, last for about a month before the compounds start to break down.

    How do I use Comfrey Fertilizer?

    There are various ways to use comfrey fertilizer and I will go more into detail in these as we continue. The list below is not exhaustive but I will cover the main ones here.

    • Liquid drench
    • Foliar sprays
    • Residues can be used as a mulch

    Liquid Drench

    When applying Comfrey fertilizer simply mix your required amount and use this as a drench. Simply pour this on the plant from head to foot soaking the surrounding soil around the root zone. Once a fortnight should be sufficient.

    Foliar Sprays

    Mix the concentrated Comfrey fertilizer to 10ml to every 1 liter of water. Add this to a spray bottle and foliar spray the leaves of your plants. Ensure to cover both sides of the leaves. Do this early in the morning for best results.


    The pulp or residue from the process of making your Comfrey fertilizer can be used as a mulch around your plants. As it rains this will then take additional nutrients that were not released during the process, and carry them into the soil area making them available for your plants.

    Related Questions

    Other Ways to Use Comfrey?

    A few other ways in which comfrey can be used in the garden.

    • Add Comfrey leaves to potato trenches
    • Use Comfrey as a compost activator
    • Use comfrey leaves as a mulch
    • Grow Comfrey as a green manure
    • Dry and powder root and leaves as an additional feed to seed starter mix

    How many times a year can you harvest Comfrey?

    You can harvest Comfrey plants up to four times a year. A bed of Bocking 14 Comfrey will give you plenty of material to produce all your own fertilizer at home. It will also allow you to try out some other uses around the house.


    Making your own Comfrey fertilizer is easy and has so many benefits. It saves you money, keeps you organic, and feeds your plants with the nutrients they require. Providing you use the Bocking 14 strain you have no issues with it becoming invasive. This plant is worth a spot in every garden.

    I hope you got some value from this post. Or at the very least enjoyed reading it and learned about Comfrey as a fertilizer. If you did why not consider signing up to my blog to get future content. It is FREE and you can do that from the signup form in the right-hand sidebar.

    Remember folks. You Reap What You Sow!

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