With hindsight, I realise that weed-mat may be a ‘solution’ favoured by those feeling overwhelmed and under-resourced: overwhelmed by weeds and under-resourced in time and physical capacity. It seems like a good idea because you think your backbreaking weeding days are over, but in fact they are only just beginning. My experience with weed-mat was difficult lesson that anything which does not belong in an ecosystem, such as plastic, is never a good solution.
But much as I hate it, black plastic is a very useful thing for smothering out the things you don’t want – for me that is mostly grass, but also things like swamp celery and farmer’s friends (whose prickles I am constantly pulling out of my clothes and my cats’ fur, and yes I know they are edible but ‘edible’ and ‘delicious’ are two different things). I am more than happy to have weeds around, especially the more useful ones, and weeds are an integral part of a food forest – but everything in moderation!
I have two types of black plastic; the weed-mat that I ill-advisedly bought and may as well re-use until I can do so no longer, and square sheets of thick plastic that arrive in nurseries on pallets, separating layers of pavers. The second type is better for two reasons: firstly because it is being re-used and I have not created a demand for it; secondly, because it is thick and non-porous it does not allow air or water to penetrate so kills anything under it much quicker. Of course this is not great for soil organisms so you wouldn’t want it on too long, or on a space where you are going to be planting anything – I use it on pathways and edges of beds where the grass is creeping in.
Weed-mat allows air and water through so does not really kill anything underneath it, just weakens and slows it down, giving you a breather if you haven’t got time to tackle an area for a while. I have an overgrown bed at the back where I am planning to move the asapragus; rather than having to constantly keep on top of it and anything escaping from it, I have put weed-mat over it until i am ready to use it. An added benefit is that some of that material will also compost down underneath creating a richer soil.
But ultimately, I am looking forward to the day when I have NO black plastic in my garden anymore. Where the shade discourages sun loving couch and kikuyu, where my ecosystem is in balance, and where the odd weed is welcome and not likely to invade in plague proportions.
In the meantime, here are some picturesque views of my garden in all its plasticy glory 😉