Making fertiliser from weeds

So far in the coronavirus lockdown, it's been hard to get gardening supplies. In particular, I haven't been able to get hold of the composted stable manure I usually fertilise the garden with. I do have the compost I make myself, but in the past I've given my plants that together with composted manure. To make up for this as best I can, I ordered a 5 litres of liquid fertiliser, but I'm also making my own fertiliser from garden weeds.

Back when I went on a vegetable growing course in 2014, they taught us how to make fertiliser out of comfrey. The reason you use comfrey is that it has deep tap roots (those very long roots that go deep into the soil like dandelion roots). This means that it can access minerals from deep in the soil that other plants with shorter roots can't get to. It brings these minerals up into its leaves, so when you turn these into fertiliser you're filling your fertiliser with all these minerals. I don't have comfrey growing in my garden, but what I do have is its relative green alkanet.

Green alkanet

As all my past attempts to dig it up have shown, green alkanet too has very long tap roots. I would also have considered dandelions for my fertiliser, even though their tap roots aren't usually as long as green alkanet's seem to be. Making the fertiliser couldn't be simpler. I took an old, clean plastic milk carton with a lid and stuffed as many green alkanet leaves into it as would fit. I used a stick to make sure they got all the way down to the bottom.

I made no attempt to remove the flowers or the stalks, as I couldn't see a reason why they might be a problem. It's surprising how many leaves you can fit in when you start pushing them down. You want to fit in as many as you can.

When it was jam-packed in, I trickled water into the top, so the milk carton was completely filled with water. I used rainwater from my water butt, but if you don't have rainwater, tap water is fine. The reason I trickled rather than poured the water in was that there were so many leaves jammed tight into the carton. I tried pouring at normal speed, but the water just ran over the sides.
I'm now putting it aside and leaving it for 3-5 weeks to stew. When it's ready, it will stink to high heaven (don't worry, that part's normal) and I will dilute it one part to 20 with water. So, to summarise, here are the steps:

1. Find some weeds with a long tap root, such as comfrey, borage or green alkanet (or even dandelions).

2. Fill a plastic milk bottle with its leaves (use a stick to poke them down to the bottom so you can fit as many in as possible).

3. Fill up with water and seal the lid.

4. Leave for 3 to 5 weeks.

5. Dilute 1 part fertiliser to 20 parts water for use.