I posted this over at The Corroboree, but why shouldn't you too learn this?
Don't you just hate the Stinging nettle? Yeah, I do too. But you know what? Your plants love it!
Instead of buying expensive fertilizer, you can just use this weed you will find all over the place. Personally I use both Urtica dioica (Stinging nettle) and Urtica urens (Small nettle), but other Nettles could propably also be used.
How is it done?Fill a bucket half full of Nettle, then fill the bucket with water. Let it ferment for 14 days, refill with more water if needed. It is advisable to stir the water every day to give extra oxygen. After 14 days or more you have a smelling bucket of black water (you will smell it when it is done), which your plant will love. Dilute this fertilizer with water 1:10, and it is ready for use.
Why does it work?Nettle is full of goodies your plants love. Not only is there lots of nutrients and important minerals, the fertilizer will also promote the admission of nitrogen to most plants. It also contains bacteria that stimulate the decomposition of organic material in the soil. Nettle fertilizer will also prevent fungus from growing. As if that wasn't enough, it also contain a plant hormone in the Auxin class, a hormone that might promote healthy growth.
You can also mix in some bark from Salix alba - this contains Salicylic acid, which also works as a plant hormone.