When using a strimmer on the edges of what passes, in my garden, for a lawn, I’ve noticed that fragments of the nylon line tend to break off all over the place.
Nylon is pretty slow to break-down naturally and so, over a growing season, the whole garden acquires a litter of coloured threads. As long as these aren’t green, they are detectable, but I really don’t want a) the dog to ingest these and b) to have to spend time harvesting the debris of earlier mowings.
Today’s invention is a strimmer line made of biodegradeable polymer (coloured green). Amazingly, I seem unable to find anything like this available already. It might take the form of a woven, raffia-like thread: certainly strong enough both to chop down weeds and to support the tension required for centripetal feeding (Ideally, I’d like to spin a cutting line automatically from fragments of loose grass, but doing so reliably isn’t straightforward).
I’d impregnate it with fungal spores which, when exposed to sunlight, begin at once to return the line to the soil.