Some of the best fertilisers are for free!

**Free Fertilizer?**

Yes, you read that correctly! It is possible to grow fertilizer at home, and this homemade fertilizer can be some of the best for your garden. Your plants may need a nutrient boost, especially during the main growing seasons. Fertilizer provides essential nutrients that help keep plants happy and healthy, but store-bought organic fertilizers can be expensive, and cheaper alternatives may contain unwanted ingredients.

We grow comfrey, yarrow, and stinging nettle specifically for use as fertilizer. Let’s take a closer look at each of these plants.

1.  Comfrey

Comfrey is an essential ally for organic gardeners. Known as garden comfrey, this plant is rich in nutrients and can be harvested multiple times throughout the season. Its leaves are abundant in nitrogen, phosphorus, and potassium—nutrients vital for plant growth. Comfrey develops a large, deep root system that can reach depths of up to 2 meters, allowing it to draw nutrients from the subsoil and store them in its leaves.

As a perennial shrub, comfrey thrives in moist soils and features a thick, hairy stem, growing to about 80 cm in height. Its flowers come in dull purple, blue, or white and form dense clusters. The leaves vary in shape depending on their position on the stem: the lower leaves are broad at the base and taper at the ends, while the upper leaves maintain a broader shape throughout, tapering only at the tips. The root is black on the outside and has a fleshy, white interior filled with juice.

Thanks to its deep root system, comfrey is capable of extracting a significant amount of nutrients from far below the soil surface, which is otherwise out of reach for many other plants. When you harvest the leaves and allow them to decompose, you create a rich, dark plant food that can be used throughout the garden. This nutrient-rich compost is particularly high in potassium, making it an ideal fertilizer to encourage flowering and fruiting in various plants, including tomatoes.

2.  Yarrow

Yarrow is a member of the aster family and is closely related to chrysanthemums and chamomile. It thrives in sunny, warm environments and is commonly found in fields, grasslands, along roadsides, and on dry, sunny slopes. This plant grows upright, typically with a hairy stem, and usually reaches a height of under 60 cm.

Yarrow is easy to cultivate and tends to spread out in a sunny spot in the garden, so it’s best to give it plenty of space. You can harvest its stems, leaves, and flowers before they produce seeds to make a liquid fertilizing tea.

Yarrow offers several benefits. It is a dynamic accumulator, a powerful companion plant, and it attracts beneficial predatory insects. As a dynamic accumulator, its deep roots help to break up compacted, dense soils while also mining for essential nutrients such as phosphorus, potassium, and copper.

 3.  Stinging nettle

Spring may seem far away, but soon our gardens will be filled with nettles. Stinging nettles (Urtica dioica) often get a bad reputation due to their painful stings when brushed against or harvested without gloves. However, they are excellent for making fertilizing tea.

Stinging nettle is a herbaceous perennial plant that can grow between 0.9 to 2 meters tall during the summer and dies back in winter. Its rhizomes, stolons, and roots are bright yellow, while the soft green leaves can measure between 30 to 200 mm long on an upright, wiry stem.

Like comfrey and yarrow, stinging nettle accumulates nutrients and minerals from the soil and stores them in its leaves in highly bioavailable forms and concentrations. This plant is rich in nutrients, vitamins, and trace minerals, making it a great addition to your diet. If you’re feeling adventurous, you can find various recipes online for nettle soup, drinks, and other culinary uses.

All you need to make liquid fertiliser from these plants are leaves, water, and a bucket with a lid.

Making fertiliser using comfrey, yarrow, or nettle leaves

1. Harvest  leaves and roughly chop (the smaller the piece, the more surface area and the more quickly the leaves break down)
2. Place leaves in a large bucket or barrel with a fitted lid
3. Add water – just enough to cover the leaves. Put a rock on the leaves to keep them underwater.
4. Stir regularly over the next six weeks.
5. This is going to get stinky! Keep the container out of direct sunlight, and after six weeks, strain the leaves.
6. We prefer adding an airline into the container for 24 hours with additional molasses to kickstart all the microorganisms.
7. Dilute your fertiliser 1L to 10L of water.  You can apply this fertilizer every 2 to 3 weeks.

We have been growing and using this fertiliser for many years, especially at the beginning of the season and again when the plants start flowering and setting fruit.

Finding Yarrow and Comfrey can be difficult, but we always buy ours at Heart Nursery in Ottery for those in Cape Town.

Happy gardening friends

Tash and Family