Couch Grass

I’m engaged in a battle with a wily, wiry enemy. Just how do you get rid of couch grass? Unfortunately, there’s no easy way. This is what it looks like…

These are the rhizomes (a few of which have produced leaves) of couch grass – latin name Elymus repens – lying on the surface after some frenzied digging by yours truly. The area of the garden where we’re creating the main border is run through with it, and we’ve been digging out great heaps of the stuff. The rhizomes creep along under the surface of the soil, building up a tangled and extensive network. Nodes at regular intervals along the rhizomes can push new clusters of grass up through the soil. Quite impressive, really. But not very helpful when you’re trying to cultivate a garden.

There are a number of approaches to take. Spraying with chemicals is increasingly seen as an unacceptable option. Glyphosate, the main ingredient of most (if not all) weed killers available to consumers, has been linked to cancer (though the big pharma companies are doing their best to hide all evidence) and only has a limited effect anyway. You’ll need to spray a number of times, leaving a few weeks between treatments, to get on top of it. You can cover affected areas, ideally with something that won’t let light through; something like thick black plastic. Okay for a bed with no other plants in it. But you’ll need to keep it covered for some time (i.e.; months, or even a year). And even then, you might not have killed it completely. And, of course, we should be using less plastic!

Digging is an option, and the one we’re using. This is the area I’m working on at the moment…

You have to be careful to get all the rhizomes out, because any you leave in the soil will re-grow. Realistically, it’s not possible to do this in one go. Our thin, sandy, dusty soil makes the process as easy as it could be, but it’s still hard work. There are cultivated plants in the bed too; these can be saved, but it’s harsh on them, because to remove all of the couch grass that’s grown in among their roots, you have to remove pretty much all of the soil around the roots. This is a time of year when you stand a good chance of the plants recovering from the shock. As we salvage plants they get put in a temporary position in our nursery bed. Ideally, having dug a bed over, you should leave it for a few weeks and then dig it over again to find the bits you missed, which may well have sprouted – giving themselves away to you. This time it should be much easier, as the soil should still be loose from the first digging over. But this is not an ideal world, and time is short, so we will probably take a chance and put in some of the plants straight away. This should work, but it will be critical to keep on top of the situation and dig out any couch grass as soon as the shoots appear.

One more option I’ve heard is to bury the stuff. This probably works best where it’s matted together to form turfs – in which case you would stand practically no chance of separating the grass from the soil anyway. The theory is that with couch grass, if you can bury it in a trench, and put a foot or so of soil on top, it will die through lack of light (a bit like the black plastic option). That sounds risky to me though. A safer option might be to cut the top few inches off and create a turf stack. Pile the turves up with the green sides together, and over time they rot down to form good quality topsoil. Here’s one I prepared earlier…

In fact this is made from standard turves, without any couch (hopefully!) The canes and string are marking out the design for the garden. These turves are in what will eventually be a border. I dug a pit so that the stack is partially buried – it’s best to exclude light where possible. And I can make use of the topsoil that would otherwise be under the stack. After six months to a year you can go through the heap and remove any perennial weeds that haven’t rotted. In the worst case, if you’ve made a stack with couch grass turves and the couch rhizomes haven’t rotted, at least the problem weeds are collected together in the one place, rather than being spread all over your plot!

With couch grass, as with most weeds, it’s a war of attrition – by keeping at it you’re constantly reducing the weed population, and weakening those that you don’t destroy completely. In time, you should get the situation under control. But even then, don’t turn you back on it for too long – you may win some glorious battles, but in the long run, you’ll never win a war against nature…

Text & images © Graham Wright 2020

Leave a Reply

Your email address will not be published. Required fields are marked *