From a dozen or so comfrey plants last year, I've already got 100+ volunteers popping up all over the place, now edging the paths. On the left, newly transferred to the skinny brick path. On the right, these were planted alongside this year's potato bed by the main path over the last month or so. Sometimes, they die right back on transplantation, but come back within a couple of weeks. I hope to have all of the paths edged with comfrey by the end of this growing season, and next year it should be magnificent, 3-4ft high.
The point is, path edges attract weeds, so it's best to get in first with something useful. And there's nothing more useful than comfrey. It can be cut back 3-4 times a year and the leaves used for turbo-charged compost or to go into a water barrel. It's on the paths, so will in the nature of things get trodden on or trundled over by the wheelbarrow: but that's fine, because it just grows back. Good bee plant, too.