Weeds -- the ultimate in low maintenance, low effort.
And a lot of what has been mentioned are weeds: arugula, garlic, Jerusalem artichokes, raspberries and blackberries, many people consider these to be "weeds". The blackberries that don't stay where they belong and come up in the garden -- weeds. The garlic that pops up everywhere -- weeds.
The question then becomes "how do I encourage the useful weeds and discourage the useless ones?"
I have no use for nightshade, it will kill
chickens. If I see any of those things flowering, out they come by the
root. Same thing with poison ivy. I don't have a goat to feed it to, so it gets yanked out by the root and sent to the landfill.
But I can add to the list of useful "weeds" that I want to establish themselves on my piece of dirt and come back year after year: dill, cilantro, lovage, chicory, mustard, prickly lettuce, dandelion, salsify, upland cress. I could do with less of the cudweed, Johnson grass, and Japanese honeysuckle. However, selectively chopping out a few weeds and letting the more useful ones proliferate is pretty low effort and low maintenance.