The answer lies in the soil. What do I put in the soil? Whatever I can get, mostly via a compost heap or bin.
Kitchen waste and really pernicious weeds go in the black bin.
Sweepings, lawn mowing's, weeds to big to be chopped by the hoe, hedge trimmings, dead leaves and plants, and anything else, goes on the general heap. That used to include newspaper and cardboard, but nowadays it has too much plastic in it.
Then it gets buried, dug in or mulched on top depending how well rotted it is.
I also bury a lot of wood, it helps keep moisture levels constant and gradually releases nutrients as it rots.
Hoe and hoe, build a tilth, chop all your weeds into it with the hoe, it feeds, protects from sun, holds in warmth and stops evaporation. It does what a mulch does and you can hoe mulch into it, it's just a couple of inches of loose stuff on the surface that the hoe moves.