UK gardening help and assistance

Nettle Liquid Manure - organic and free

Nettle Manure is an organic and free plant / soil feed which can be easily made in any garden, all you need is some young nettles and some water (ideally, rainwater).

Roses, tomatoes, roots vegetables, legumes and almost any other plant seem to benefit from its application - colours, plant growth, flavours and textures all seem to improve.

Nettles have deep roots and as they grow, they bring up trace elements from the deeper soil which are essential to plant health but which are often lacking in regularly cropped top soil.

Nettle Manure can be started in the spring when the young nettles begin to appear and can be continued throughout the Summer and early Autumn to give a valuable plant/soil feed throughout the main growing seasons.

What you will need

  • A watertight, open topped container but with a cover - metal or plastic will do - don't complicate things by having a container with a tap near the bottom, the nettle stems will tend to block the outlet
  • Some nettles
  • Some water - ideally rainwater
  • A weight - an old brick will do

Making Nettle Liquid Manure

  1. Gather the nettles - young nettles are better because they break down quicker and have less plant fibre than older plants - but older nettles will do although they will take longer to break down and give more fibrous waste.
    If you can collect the nettles by mowing, this will help to begin to breakdown the plant structure and speed the process - don't worry about any grass also collected. Otherwise, before putting the nettles in the container, bruise/crush them - this can be done by twisting them in your hand whilst wearing tough gardening gloves, or spread the nettles on the ground and run a lawn mower (with a collecting box) over them.
  2. Fill the container with the cut, bruised or crushed nettles.
  3. Add water - with the nettles lightly pressed down, add water just to cover them - adding too much water will reduce the strength of the manure produced.
  4. Cover the container to prevent rainwater causing it to overflow.
  5. As the nettles breakdown, the plant fibres will rise to the top, so after a few days, place a weight on the 'mush' to hold it under the water. Using a stiff piece of mesh, just narrower than the container, under the weight is a good idea to help hold all the fibres down.

Nettle Manure takes about three to four weeks to 'mature' - and it does 'mature' to give a fairly earthy smell, so you may want to place the container somewhere out of the way.

More nettles and, if necessary, water can be added to the container throughout the season. Lift out the weight before adding more nettles - it is best to leave the old plant fibres in the container until the end of the season and then put them on the compost heap.

Remember that if you add more nettles without water, the 'brew' will tend to strengthen, and when you add water the 'brew' will be diluted so you may want to leave the 'brew' to mature a bit before you take any more to use.

At the end of the season for nettles, carry on using the 'brew' and once the last has been used, the container should be cleaned out, the nettle fibres put on the compost heap and stored for use the following year.

Using Nettle Manure

As mentioned earlier, Nettle Manure does have a bit of a earthy smell, so using it to feed houseplants may not be ideal although the smell does tend to fade once it has been applied.

Nettle manure can be used as a soil or foliage feed, however when made with the right proportion of water to nettles, the brew needs to be diluted before use - the ideal strength is about the colour of tea - with a full strength 'brew' this can be around 1 part manure to 10 parts water.

The mature can be used in a spray but it needs to be strained before use to remove the small fibres which will inevitably be floating in the solution and could bloke the spray.

An addition benefit of using nettle manure is that it acts as an insect repellent - just put it on the soil or foliage and the insects will go away.