Killing off couch grass

[Len P]

Hello!

We have just taken over a plot which is weed filled with cocuh grass. We have strimmed down and now plan to use Glyphosate.

The question is, is there anything to be gained from then covering the ground with carpet or does the weedkiller perhaps need sunlight to work?

Hoping that someone can clarify.

Len

[Len P]

[RenishawPhil]

DON'T USE CARPET.

They are not good and many allotments frown on their use.

Simply spray on a dry day then I would respray in two weeks.

But you should do it soon while the weeds are still growing well.

[ed dibbles]

Welcome to A4A Len P.

Glyphosate is particularly good at tackling grass, including couch. I agree spray now and again in a couple of weeks if necessary. It should clear a pretty large area relatively quickly.

Couch is one of the easier perennial weeds to clear manually as the roots seldom go down more than a forks depth.

Of course manual clearance takes somewhat longer than Glyphosate.

[Robert_Brenchley]

If you want to put anything down use black plastic, but dig around the edges so the roots can't just run in supported by leaves out in the sunshine beyond the plastic.

[Unwashed]

If you've already sprayed then you now need to leave it alone for two weeks so the poison can get down into the roots and kill the plant.

Then dig, don't cover.  The ground needs cultivating.  I would just dig the whole plot through - and don't bother pulling any roots or weeds out at this time or you'll never get it dug.  If you can strim the whole thing down right to the ground then so much the better, and if it takes you some weeks to dig the plot keep it strimmed.

Once you have the ground cultivated the soil starts to become loose enough to hand weed any re-growth of couch - and from what I've see couch always re-grows after glyphosate. 

Don't try and get the bed completely clean in one go or it'll take forever and you'll not cover the whole plot, just spot weed when it shows itself and get the worst out - I reckon it takes the best part of a year to clear a bed completely.

You'll be thinking soon about planting autumn onions - onions don't compete very well with grass and it's difficult weeding out couch from an onion bed - you might have to forego the autumn onions this year.

If you're on clay couch can be incredibly tenacious and it can take a lot of work to cultivate a good tilth, so good luck.

Couch roots compost fine, but i like to leave them on the surface to scorch in the sun for a few days just to be sure they're dead, and then make sure you've got most of the soil off (difficult on heavy clay) when you put them on the compost heap or it'll smother the heap and it wont rot down.

[Len P]

Great advice thank you to all, this seems like a friendly place!

[Robert_Brenchley]

Once you start to get on top of it, couch isn't as hard to deal with as some weeds. The roots are strong enough to get the whole lot out in one if you're careful.

[Unwashed]

Once you start to get on top of it, couch isn't as hard to deal with as some weeds. The roots are strong enough to get the whole lot out in one if you're careful.

On a light soil that's quite true, but I've gardened on heavy clay too, and there it's a real swine because the ground holds on to every inch of root.

[Pescador]

Len, Please be very careful when you spray.
Keep the pressure very low, and only do it when there is no wind.
I am a great fan of glyphosate, but it only takes a tiny bit of invisible drift to cause serious grief to your neighbours.

[GREGME]

Hi good luck with this
I was in a similar position last year and I think you are doing the right thing - but I would suggest that you should dig a little and become familiar with what couch grass roots looks like - sort of underground ivory coloured barbed wire. In my experience it keeps going over the winter if much slower and it lurks in grassy paths between allotments so will always be an enemy.

[Digeroo]

My advice when you start to put in crops is to put in large plants, such as broad bean, potatoes brassicas courgettes, and keep handy with the hoe and every time the couch raises its ugly head you hoe it off asap.  Perhaps the worst thing for me  is strawberries, it is so difficult to get couch out from between them.   

I am not sure the roundup kills the couch, I tried painting it on the leaves and it hardly noticed.

[RenishawPhil]

My advice when you start to put in crops is to put in large plants, such as broad bean, potatoes brassicas courgettes, and keep handy with the hoe and every time the couch raises its ugly head you hoe it off asap.  Perhaps the worst thing for me  is strawberries, it is so difficult to get couch out from between them.   

I am not sure the roundup kills the couch, I tried painting it on the leaves and it hardly noticed.

I found glyphosphate was very good at killing couch if sprayed well

[Unwashed]

My advice when you start to put in crops is to put in large plants, such as broad bean, potatoes brassicas courgettes, and keep handy with the hoe and every time the couch raises its ugly head you hoe it off asap.  Perhaps the worst thing for me  is strawberries, it is so difficult to get couch out from between them.   

I am not sure the roundup kills the couch, I tried painting it on the leaves and it hardly noticed.

I found glyphosphate was very good at killing couch if sprayed well

I've certainly seen it grow back - infested plot will be sprayed and then rotavated, and then it blooms green as the couch re-emerges.  As you say, that might be due to the application being poor, either not waiting two weeks for it to take effect, or not spraying when it was growing vigorously, or simply not covering all of the grass, but I suspect that with the extensive network of rhizomes that couch is able to keep a reservoir of viable root protected from the poison.

I've never had much of a problem with it re-infesting from grass paths - I've had the problem (I built up my paths with infested soil), but it's been manageable.  If the paths are kept well mowed the couch will die off in a year or so anyways because it can't form a sward like lawn grasses, and then it just needs regular weeding of the path edges where it starts to grow into the beds, and if the paths are edged it's easy to run up and down the edges spot weeding.

[Fork]

Nothing wrong with carpet so long has its hession backed and not foam..its the foam that can be toxic I believe.

I covered an area which I knew I would not be able to tackle the normal way,ie dig....and I found that the lack of light weakened the couch so much that it was very easy to pull/dig out at a later stage.

I have a new plot now and I have cleared 3/4 of it....I will cover the rest very soon and attack it later on in the year.