If you are rich and have no weeds, you can buy pricey jugs of organic kelp, seaweed, fish fertilizer etc. to dilute with water for a happy, healthy garden.
The rest of us can turn to weeds, rambunctious herbs or even excess leaves from vegetable harvests.
Simply toss this greenery into a bucket, cover with water and let things steep until they stink which should take about a week to 10 days.
At this point strain the liquid into a bottle and use the potion the same way you would seaweed or fish fertilizer.
Dilute with water at a rate of 50:1
(50 parts water to 1 part weed fertilizer which works out to 1 gallon of water to 5 tbsp (1/3 cup) concentrated weed fertilizer)
And there you have it. A free, rich, fertilizer.
In fact, the only thing poor about this fertilizer is the cost.
Weedy type plants are capable of pulling an insane amount of nutrients out of the soil and will give this back through the fermentation process. Use an assortment of different plants (be sure that none of them have been sprayed with herbicides) for best results.
If you are fertilizing edibles make sure none of the weeds you are using are poisonous. Some safe choices could include:
Stinging Nettles (wear gloves while picking)
As always, thoroughly wash any produce before cooking, consuming or canning it.
Once you start making your own fertilizer you will see your invasive plants and weeds in a whole different light. You may even wish you had more!