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  • Writer's pictureJanice Gill

How to Make Your Own Plant Food.

Tortoiseshell butterfly feeding at a comfrey flower,
Tortoiseshell Butterfly on Comfrey. Photo by Janice Gill

When growing organically at home, it's expensive to obtain a safe fertiliser. Even the best will impact the local water table to some extent, not to mention they are supplied in plastic and shipped from factories many miles away.

But did you know there are plant foods you can grow in your own garden which are natural and safe for the environment?

As a bonus, they support a range of beautiful and important pollinators.

Read on to find out more and learn how to make your free plant food.


Comfrey is a native plant in the UK, Europe and Asia. It thrives in damp grassy areas such as riverbanks. If you have an area in your garden that never seems to dry out, that's the ideal spot to naturalise some comfrey.

This plant is a herbaceous perennial, so it will die back in late autumn but burst back to life in spring. It is part of the same plant family as Borage and has similar hairy leaves. The flowers appear in spring and are a valuable source of nectar for many kinds of pollinators, including bees and butterflies, such as the beautiful tortoiseshell butterfly above.

In addition, Comfrey can be used as free and safe plant food. There are several ways to do this

  • Harvest the leaves throughout the season, chop and add them to your compost bin. Mulch with compost as usual.

  • Harvest the leaves and use them as a mulch directly around your plants. This method can look a little messy for some people's taste, especially if there is not much leaf cover from your plants

  • Harvest the leaves and make a tea to water around your plants. This is the fastest way of getting the nutrients from your comfrey to your precious plants.

To make a tea, fill a lidded bucket with leaves, and fill with water till the leaves are covered. Pop the lid on and leave it to stand out of the way for around six weeks. Be warned, as the leaves decompose, they smell. And not in a nice way. Once the time is up, pour the liquor into a water container through a sieve. The mushy remains can go on your compost heap and will even speed up the composting process.

The tea will be too strong to feed your plants at this point. You'll need to water it down - 10 parts water to one part tea. This can be used when watering or as a foliar spray.

So, what's special about Comfrey that you can do this?

Comfrey has long tap roots that draw up nutrients from deep underground, where it's inaccessible to shorter-rooted plants. These nutrients are released as the leaves decompose and include Potassium, Nitrogen and Phosphorus, the main constituents of mass-produced fertilisers.

Red admiral butterfly on Winter flowering jasmine hedge.
Red Admiral Butterfly, photo by Janice Gill

Stinging Nettles

These are not the favourite plant of many gardeners or anyone else unfortunate enough to come into contact with them. However, in organic and wildlife gardens, they are invaluable. While they don't have beautiful flowers like comfrey, they provide a habitat that protects a number of species from their predators. These include the caterpillars of the gorgeous Red Admiral butterfly.

Like comfrey, nettles can be used to make a potent tea, which is high in nitrogen, to promote leafy growth. It's made in exactly the same way as comfrey but takes four weeks to decompose instead of six. You can keep cutting throughout the season, but it's worth allowing some of your nettle patch to grow to maturity for the beneficial species it attracts.

Go Double

For an all-round plant food, you can make tea from a mix of these leaves which is great for heavy feeders such as fruit trees, roses and tomatoes. Follow the instructions for the comfrey tea, but check from four weeks onward. If the stuff in the bucket is black and smelly, you're good to go!

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Jul 18, 2023

Pretty cool! I love these photos and love tea. Never heard of this kind before. I'll have to give it a try. - Elisa

Janice Gill
Janice Gill
Jul 18, 2023
Replying to

This tea is for your plants, but you can make one for yourself.


Jul 18, 2023

Jan, thanks for a fascinating post. I am something of a gardener, limited by the desert environment in Phoenix, Arizona. I used to drink comfrey tea for its healing properties, until there was a scare about comfrey being bad for humans. It went off the market as a tea. But I would love to have my own supply, growing in the back yard. Thanks for the inspiration.

Janice Gill
Janice Gill
Jul 18, 2023
Replying to

I hope you are coping with the awful heat!

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