Ok, so it sounds vaguely pagan ritual site-ish, but rather than that, our fertility patch is actually all about growing plants especially to cut them down as a nutritious mulch or to turn into liquid fertiliser to enrich our soil and boost our plants.
We've reclaimed a little of the wilderness that borders our concrete yard by slashing back the nettles and covering with a thick, biodegradable mulch made up of a layer of cardboard (taking care to give each sheet at least a 20cm overlap with the next), covered with a 5cm layer of soil, covered with a top layer of straw.
On top of this, I've planted comfrey plants. I've chosen the Bocking 14 strain as it doesn't spread around the garden and become a pest. The best way to propagate comfrey is said to be by taking root cuttings. I could have done this myself as I've got a small patch of Bocking 14 already, which has been working wonders on my tomatoes. But I have never taken root cuttings and do want to make sure these plants work, so I've bought some root cuttings this time around and they've worked really well. Next time, perhaps I'll be a bit more adventurous!
To plant them out, I just cleared back the straw and soil and punched little holes in the cardboard - large enough for the roots to be able to find their way through, but small enough that weeds will struggle to push up through from below.
Then I piled in a good couple of handfuls of soil and planted the cutting in that. They're now doing well - apart from a couple that got munched by the rabbits. I'll leave them be for this year and then by next year I should have some good healthy plants that I can start cutting for mulch.