Pulling weeds out of your garden is one thing, but disposing of them once out of the soil in a way that ensures they don’t reshoot can sometimes be a struggle. Turning them into a weed tea gets rid of them for good while producing an inexpensive and nutritious fertiliser for your garden.
Composting your weeds is a great option, but the time taken between pulling them out of the ground and turning them into something you can return to feed the garden in the form of compost can take months. Fermenting them in water over a few weeks, however, is a fast and effective way to not only dispose of them, but to turn them into food for your garden.
What To Make It In
You can make your weed tea in just about anything that holds water, although given the smell it will inevitably develop, it’s best to have a container specifically for this purpose. Instead of buying something, you could ask your local bulk wholefoods store if they have any containers they no longer need, or buckets from restaurants are great, too, and will often come with a lid.
Not Just Weeds
While weeds alone will make a nutrient-rich tonic you can use either to water your plants or as a foliar spray, adding other plants and organic matter will give you a higher concentration meaning your tea will go further.
Tap-rooted plants like comfrey or dandelion draw nutrients from deep within the soil and store it in their large leaves. Any plant with a reputation for being a compost accelerator is going to be a great option in this application, and an excellent way to keep on top of your vigorous self-seeding plants like borage and tansy.
A handful of chook manure or worm castings will add to the potency of the finished product, too, though fresh chook manure may require a longer time to break down in the bucket and a higher dilution before it’s applied.
Brewing Your Tea
Much like when you’re making a fermented drink for yourself, time is key to producing the best results when brewing a homemade fertiliser. Once you’ve gathered all of your plant material, you can chop it up into smaller pieces which will mean it will break down quicker, before then covering the whole lot with water. If you like, you can stand your water uncovered for 24 hours to allow the chlorine to evaporate, which will be a kinder host for microorganisms, but it’s not essential.
Once the weeds are immersed in the water, you have a couple of options. The easiest way is to simply leave it to ferment for between three and six weeks, although it develops a very pungent odour, so your family and neighbours will be thankful if you can keep it covered. This will also deter mosquitos from laying eggs in your stagnant liquid while it’s fermenting.
The other option is to stir the tea each day, which speeds up the process slightly because you’re introducing oxygen. You’ll also find it doesn’t develop quite as bad an odour as a stagnant brew, but stirring it every day or two is a little bit more labour intensive.
Once your fermentation has finished – it should be a deep brown colour and smell well and truly decomposed – strain the liquid off your weeds (add the plant material to your compost) and what you’re left with is a concentrated liquid fertiliser.
It’s not a bad idea to wear gloves during the straining process – the concentrated liquid fertiliser smells particularly bad and it’s very hard to get rid of if it spills on your hands or clothes. Dilute the liquid to about one part tea to 10 parts water – or at least until it’s the colour of weak black tea – before applying to your garden. Seedlings or young plants will benefit greatly from the nitrogen boost if applied once a week. It’s important to still add solid organic matter like compost and worm castings to your garden, which unlike the weed tea, will break down slowly over time to both feed and improve your soil.