[Gleavo]

More on my obsession with clearing 80 foot of the stuff!

OK:

Strimmed /covered sections with black dp plastic/dug 2 onion patches for winter onions.

There are sections between the black plastic that remain just strimmed. They have started to re-sprout.

Now I was told it's probably too late in the season for round up as they won't take it into the root properly. I'm thinking though, if it is re-sprouting/growing/active then surely they will still take it into the root?

So is it worth a late season spray pre-dig? Or will I just be wasting the stuff?

Thanks
G

[RichardA]

 I only have a little bit of couch grass now, mainly because I have grass paths between my various plots and it is in there so creeps out from time to time. If I see it I spray it. So if it was me i would spray, give it a reasonable time to act and then slowly and carefully dig and lift out every scrap of root.
I understand grass will grow as long as temperatures are above about 6 degrees C perhaps less during the day.
Best of luck
R

[Lee1978]

You need to get in there and dig it out, that is the only sure way of eradicating it. Covering it with plastic etc will not kill it, it's as tough as old boots

[paintedlady]

I've spent a lot of time and effort trying to dig couch grass up and I have found that covering the soil for a good length of time and/or using glyphosate has been much more effective against couch grass.  The problem lies with its root system.

If you think neither treatments have not worked, there may be several reasons:
- when using an appropriate weedkiller, you may need to do more than one treatment (the first treatment might knock it back but couch grass have an extensive root system and parts of it may survive and throw up shoots which a second treatment should kill)
- when covering the soil with black plastic, total exclusion of light is imperative (a tiny sliver may just be enough to keep it alive)  Also be aware that due to its sprawling root system, some of the plants sharing the same root may be in full sunlight and be keeping the whole thing alive until favourable conditions return
- when covering a bed, be prepared to keep it covered for a long time.  All plants need some light to survive, and if excluded, the food in the roots will keep it alive until it returns.  However, even this is a finite source and it will eventually die.  I'd like to say 12 months minimum, maybe 2 years at most ... if this is too long, you could cover the bed with plastic and plant crops such as squash, sweetcorn or tomatoes through it (I chose these because they'll also benefit from the soil being warmed up by sunshine on black plastic)
- when ground has been cleared, this will encourage seeds to germinate and grow giving the impression that none of the above treatments actually worked

Talking of tomatoes, I read somewhere that growing these in a bed will prevent couch grass from growing.  I'm still unsure of the results but this year I grew tomatoes on a new bed that had been originally infested with couch grass and it would be true to say that after clearing the tomato plants, there were no couch grass (but plenty of marestail  )

[Pip Judgeford]

I try to garden organically but my one exception is round up for cooch.     Nothing else seems to work.

Most grasses are pretty sensitive to round up and if I am spraying outside of the fast growing season I put in a surfactant with the round up.  Now you can pay a truckload for some fancy chemical to give your round-up sticking power and be more effective, or you can do my mate's trick of a teaspoon of milk in about 5 litres of water (& whatever the round up amount).  Cheap, effective.

Pip

[paintedlady]

I forgot to mention my asparagus bed ... when it got choked with couch grass, I knew trying to dig it up would also risk damage to the asparagus roots, so they got sprayed in early spring just before the spears appeared, and it worked fine 

[Pip Judgeford]

Thanks Painted Lady for that tip re sparrowgrass.  I've only nuked couch in bare garden beds and do have it in the sparrowgrass bed.  But my harvest started 3 weeks ago so I'll have to remember for another...45 or so weeks :blink:

Pip

[Gleavo]

Thanks all - will do a test area tomorrow (with milk - thanks Pip!  )

If it is effective I'm going to carpet bomb the stuff like it's agent orange!