Nettle Fertiliser




Introduction: Nettle Fertiliser

About: Hi, I'm Tim. I work on the railways during the day, run a scout troop and have a blog (see above website link) where I discuss my allotment and projects!

Apologies to my American cousins who want to stick a Z in Fertiliser.  I'm English.

Fertiliser isn't cheap - neither is organic fertiliser.  I'm also a cheap skate and seeing as during the growing season you need heaps of fertiliser for fabulous veg, here's a guide to making your own.

For this instructable you only need:

Container - preferably with a lid
A thwacking stick.

Step 1: Collecting Nettles

Nettles are spikey stinging beasts found almost everywhere - especially on waste ground or usually beneath anything you are balancing on in the garden.

Good stout gloves are a must, however you may also need a long sleeved jumper or thick long sleeved t-shirt to get a proper harvest.

Harvesting is simple - just pull up plant.  Leave the roots if you can, but you ought to be able to snap off the stems without too much effort.  You'll need enought to fill your container - don't be afraid to compact it down either.

Step 2: The Thwacking Stick

All you need to do is damage the nettles.  A lot.  Take out those years of stinging anguish with your thwacking stick.  The more damage you make, the more surface area there is for bacteria to break down the nettles quicker.  I've done this process without thwacking, but generally it's much quicker to break down the nettles first.  You could even stick them in the blender...

What is a Thwacking stick you ask?

Its anything which makes a satisfying twacking sound!  You can infact use any device for mashing and smacking the nettles - a lawn mower can be used to finely chop the leaves, or just like I have, a bit of 2x1.

The twacking can be done on the lawn, on the pavement or in the container (as long as it's strong enough)

You can either fill the container with water and pulverise them there, or twack and add later.

Step 3: Souping It Up

Some people thoroughly recommend you try nettle soup, but not this nettle soup.  Add water to cover the nettles (if you've not done already in the thwacking stage), cover with a lid and leave.  You can stir it, but you won't want to regularly.  Then leave for three to four weeks.


Just had to add a step to comment on the smell.

Within a week (or less) the smell is horrendous.  This is normal, hence why we recommend a lid.

Step 5: Applying

Nettle fertiliser is useful for all above ground plantings.  It's high in Nitrogen.

Dilute 1:10, it makes a weak tea colour which still stinks after being watered down ten times!

Apply weekly to plants - too much and you can scorch the leaves.



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    16 Discussions

    Nettles are serously good eating! I'll take out my revenge on the dinner plate instead

    ...but seriosly this is a great method for upcycling your garden weeds even after they have gone to seed and you don't want them in your compost.
    In LA the best (and probably most abundant) weed to use is'll recognise it cause the leaves kind of look like those of a geranium.

    and yes THE SMELL!  it's called green manure for a reason!

    1 reply

     No idea on the mallow - never heard of it and I don't think we have it in the UK - but if the leaves are high in potassium and/or nitrogen go for it (each have different uses)

    This looks fantastic! I've always wanted to have my own compost type thing! I just have a couple of questions:

    1. Did you install the spout yourself on your garbage bin thing?

    2. How much water did you put in? Maybe I was reading too fast and missed it.

    3. Do you think you could use it with cacti pads?

    4. How long does it take before the juices are all full of plant goodies?

    Thank you! This looks wonderful!

    1 reply

    1.) Yes I did.  When drilling in plastic, use a slow drill speed and use tape which'll stop it from slipping and holds the plastic together a bit. 

    2.) I filled it up with both nettles and water

    3.) No idea on the cacti pads - it depends what type of nutrients they store.  I'm assuming they don't fix nitrogen in the leaves, so probably not.

    4.) it can take a few days for the stuff to decompose and start to smell but leave it for a month or so before it's properly potent.  Keep topping it up and it'll keep going.

    Are there any sorts of "weeds" that wouldn't work well for this? At least to varying degrees they should all decompose, right?

    1 reply

    You can use manure as well - but put it in a sack.  There are other 'weeds' such as mares tail which you can use as well as the bocking variety of comfrey.

    I'd take care with other leaves and plants because some like rhubarb leaves make a toxic solution which kills insects - useful as a natural 'organic' pesticide.

    While I respect your right to misspell words due to cultural differences, if you're going to bring it up, at least use correct grammar in that sentence. Whom is incorrect in that usage; it should be "...American cousins who...".

    4 replies

    Hi Karossii - I'm confused - it doesn't say whom, it says who? And nope, I didn't change it in the edit screen.  You'll just have to trust me on that.

    Karossii - I didn't, so unless there's instructable gremlin grammer checkers (or mods as they're commonly known) doing this sort of thing, it may have been imagined! I often make that mistake, but not on this instructable it seems!

    Well, perhaps my eyesight is going... but I am quite certain it said whom, not who... However I have nothing to prove that it was there. And in any event, it isn't a big deal; my initial comment was as much tongue in cheek as anything else...

    This is a great way to use up nettles, thanks for posting! I've got some dead nettles that will be giving their lives to nourish my veggies this year.

    2 replies

    fresh nettles are better - not sure if dead will work.  Dried nettles make good human drinking tea - very good for pregnant ladies.

    Oh sorry for the confusion, dead nettle the common name in the US for lamium purpureum. As it turns out they are not related to the stinging nettles in the instructable; however they are supposed to be nutritious so I'm still going to try and make fertiliser from them :)

    Here's some stinging nettle tea I made a while back from fresh nettles. It tastes like asparagus!

    I've used this same technique to make a fertiliser from comfrey.  It makes a great all-round fertiliser containing nitrogen, potassium and phosphorous . . .  and the smell is equally vile.
    Don't forget, if you're doing this with nettles, leave some for the butterflies.  Many species lay their eggs on nettle leaves.

    (That looks more like a thwomping stick to me.  My thwacking sticks have always had a bit more whippiness to them to give the distinctive thwacking sound #;¬)

    1 reply