Cooch/Couch Grass on site where wanting to plant a food forest - Any guidance appreciated

Hello wonderfull world wide Permies,

We have Couch/Cooch grass all over a site where we would like to plant a food forest. Obviously this is not ideal, i wanted to know if anyone had any experience in low cost (and ideally quick! of course!) ways to remove/work with the grass when creating a food forest?

We are in an alpine environment, south island, new zealand.

Have seen research relating to a few options, namely goats and/or chickens on the site to eat and remove the grass or black plastic cover for several months....however we are really operating on a LOW budget!

Would really appreciate anyone's advice about this, please only comment if you have actually carried out the advice you have given.

Many thanks in advance,

Doug.

Doug, cooch isn't someting I've had to deal with, so no pretending here!
But I'm definitely nosy; where are you down South? I'm originaally from the South Island, so I'm extra interested...

I've not had any luck with sheet mulch - on the contrary it strengthens the couch grass by killing off competing weeds.
I dig up as much of the roots as I can and then plant densely with vigorous crops that can out-compete what's left.

ditto from me on cooch vs mulch. (vic, australia).
only long term success ive had was digging out the sod, refilling with compost etc and building new soil over 12 months prior to planting. also requires a very strong border to stop it encroaching from surrounds.

Multiple layers of cardboard, well overlapped, then building beds on top, then mulching, will stop couch in its tracks. You need to exclude light.

We have a rhizomatous Agropyron spp. around here that sounds similar. I have tried layers of cardboard under 6" of wood chip, and failed to get control, however the survivors were easier to grub out... I wouldn't recommend that approach at any scale. I also have used chickens for tillage, adding mulch to a pen over time... worked for just about everything except rhizomatous grass. Now I lead towards tillage and a clean cultivation crop for a year with intensive weeding (something like corn, etc...), then sowing it into a manure crop to start the forest (clover, lupine, dock etc...), and being diligent on spot weeding. The other way to look at it would be to consider a woody understory (elderberry around here...) for several years during establishment at try to shade it out... good luck.

I have a similar invasive and I tried 2 layers of cardboard, 4" of compost and then 12-16" of wood chips. Guess who loves its new competition free space?

Two layers probably isn't enough, I would do four minimum, probably more depending on the thickness of the carboard. And it needs to be well overlapped. This works with couch. Don't know about other invasives.

Hi all,

Thanks for your wonderfull responses. Apologies for my late response! Very interesting to hear how everyone else here is trying to deal with it, and what does and doesnt work.

I am currently reading Jackie French's guide to companion planting and she gives the following advice about using comfrey to contain cooch:

(on page 32)
"Keep grass out with a border of comfrey. Comfrey is deep rooted and will keep out even kikuyu and couch.".
"I find that in spring our comfrey starts growing 10 days before our kikuyu."
"...other grass barriers: Other deep rooted plants like comfrey are dock, french sorrel and chicory."

Has anyone tried using Comfrey with success?

In terms of a physical barrier, how deep down have people gone when creating this?

Thanks again,

Doug.

p.s. this is in relation to a couple of sites, one is a community food forest near Wanaka, the other is a private residence in Hawea Flat and also Queenstown!

I over seeded white clover on the original couch sod garden paths in the early spring - frost seeded, just scattered seed on the surface. I kept it mowed and watered and by the end of summer the white clover had out competed it by 90%. Not sure from your post if you want bare ground or just something more beneficial than couch, but perhaps a two season approach would work. The white clover is pretty aggressive in itself and will grow into beds, but not so bad as couch and at least improves the soil. I edge the beds and leave a little ditch, an easy single shovel depth. This slows the invasion of both clover and couch a lot.

Clover seems to like a lot of water - the clover outside the overhead watered area did not thrive. Not sure about survival over the long term.

Hard to tell in this photo, but the path in front of the fence was solid couch at the beginning of the season...

We call it twitch grass or quackgrass around here, but it's the same thing-- very difficult to get rid of.

At my son's end of the farm, the soil is a sandy loam. He is able to get rid of Agropyron repens in a small area such as a veggie bed with a relatively modest effort of pulling and heavy mulching.

At my end of the farm, the soil is a heavy clay loam with a bad hardpan down 1 or 2 feet- the result of generations of abusive traditional farming practices,most notably plowing. Twitch grass brings out my inner Klingon and I consider it a "worthy opponent". Apparently, A repens just loves heavy clay with a hardpan, so much so, many authors call an invasion of it an indicator of this soil type.

My battles with this species are many, but the only truly effective methods for removal that I have found all include light exclusion.

1. Heavy cardboard (or plywood, 1 inch thick layers of newspaper, etc) - 4 to 6 layers deeply overlapped. A repens can send runners out for 3 or 4 feet looking for light - they can easily sneak between gaps in cardboard placement. This cover has to stay in place for at least 1 year with no gaps appearing. I have found minimal coverage of the cardboard with mulch- just enough to keep it in place- is best because then it doesn't decompose as quickly as is more likely to last long enough.

It is best to do fairly large areas at a time - remember the very long runners that will be sent out. I have covered smaller areas of around 10 square feet for over a year only to uncover them to disclose a teeming, seething mass of very healthy A repens roots (and nothing else), which were found to be connected to happily photosynthesizing leaves 4 feet away on the edge of the mulched patch.

2. Plant tees that will cast deep shade. Slow, but effective in the long run.

3. Solid poured concrete, such as a patio - not gravel or concrete patio squares. I have seen A repens appear in the middle (over 10 feet from any edge) of a professionally built gravel parking lot in town.

Things that have not worked for me
1.Tillage - this is like trying to get rid of comfrey by tillage, the opposite happens, you propagate more of them and they laugh at you.
2.Pulling/digging up all the roots one can find, then keeping all resprouting leaves to less than 4 inches tall by pulling them out when they appear. I read this one in a book, which claimed that at less than 4 in tall, they weren't contributing to the plants' reserves, thus one could eventually weaken the plants and they would die. NOT.
3. Pouring boiling vinegar over them. Obviously I had my desperate moments.
4. Planting buckwheat thickly to smother them out. A repens is allelopathic. Even with a light cultivation to form a seed bed, hardly any buckwheat sprouted ( and I had sowed the seed so thickly the ground was barely visible and I kept it well watered) and what did sprout never grew more than 4 in tall and stayed a sickly pale colour.

I am going to continue to experiment with smother crops this spring. I have a patch of twitch grass covered up with cardboard since last fall which I will uncover in late spring and plant thickly with buckwheat. Hopefully this will give the buckwheat a bit of a headstart. The theory is that buckwheat grows so thickly that it excludes light. I will sow rye into the late maturing buckwheat and allow the rye to stay in place for a couple of years. This should also help the hardpan issue. I have had old timers warn me though that getting rid of the rye may be a problem in itself.

I think that a goat enclosure around a patch of A repens should work as well, since goats will eat everything down to bare dirt if not rotated frequently. I would like to try other livestock experiments as well ( sheep, pigs, chickens), but am not living full time on my land yet, so these will have to wait.

Interesting to note that A repens roots are nutritional and medicinal. They are a famous famine food of times past, so maybe in the event of hard times, I will be glad I couldn't get rid of them. I have tried eating them raw and they have a mild, slightly sweet flavour - not bad,really. I have read that they can be roasted and ground for a coffee substitute, like chicory or dandelion. I plan to try this out someday.

Medicinally, a tea made from them is used to treat kidney infections and kidney stones- they have a mild diuretic action. They are also used for prostate and liver problems.
So..... maybe I should turn the problem into a solution and just consume the little darlings?

Manitoulin Mary

I have had success in eradicating couch grass from smallish areas using old corrugated iron, overlapping it and letting it bake in the sun over summer. This worked for me because I had a big stack or iron on the property and ended up with more when I did some renovations. Needs to be weighted down, we are in North Canterbury (New Zealand) and get some fantastic winds.

No luck with sheet mulching, probably not using a thick enough layer.

I kill couch grass by laying a plastic tarp over the area and waiting a couple to a few months
until all the couch grass has begun to decompose and then take the tarp off and torch burn the rest

I am jealous. I have tried similar tricks with no luck here in northern Ontario. I covered up a large patch of quack grass with a heavy tarp ( 10 x 15 feet) weighed down with plywood 6 months ago. It is even located with a driveway lining 2 of the sides of the tarp, so only 2 sides are open to rhizomatous invasion.
Checked it a couple of weeks ago. No green sprigs of quackgrass under there, but certainly no rotting of quackgrass roots,either. No,instead there is a solid patch of healthy white A repens roots. I found them going down 12-18 inches. I will leave the tarp in place for another 4-5 months in the hopes of weakening the quackgrass enough so I can establish a white clover groundcover come spring.

WOW! I thought it was pervasive, but I only meant here in this valley I farm in. New Zealand is a long way from west coast Canada, so it must be one of those traveled-by-ship invasives with nothing outside its original domain to keep it in check. I just learned today that cooch roots are alellopathic as they decompose. Damn, eh! That was from a BA in sustainable agriculture I meant today. I'm not actually sure thru the four way crosstalk we had, but will learn more in coming days as we keep in contact. I've been pulling it out of the ground all day, all spring, almost every day. I want to redo our gardens to obviate this problem, obviously . Immediately tho alellopaths vs. allelopaths or however spelt. Fall rye I know can border off but you'd still have to root out all within your garden's borders and good luck with that, eh.

If you cant beat 'em join in the fray, or however they used to say that. I hear the local Dukhabors of Russian extraction in our area used to eat the stuff. Then by the maybe strange but well founded signature theory of herbal medicine cooch roots ARE like live wires! It's the most pervasive aggressive plant i've seen and so who doesn't want that profile. I've heard even mere Paul Wheaton wants to conquer the weirld. So maybe we can all conquer whatever, even mere home projects before shooting higher on the cooch grass. I hear the previous generations here dried the roots and milled them into a flour for baking, but then juice the grass too. I bet it rivals well the fabled wheatgrass. I may yet talk myself into becoming a cooch grass farmer. Start a craze or just expand my own, become fabulously rich, hehehe. Sadly , (tear or wink?) OgreNick

PS: Maybe I'm just a shallow digger but cooch roots dont seem to be deep divers. Perhaps they dive after moving along the surface (a good path choice for nearly any root, or so I'd think). Maybe they break off before diving down a stretch. Gonna dig deeper tomorrow. Recall now hearing others in the valley dug down 2+ft. but i thought they were just boasting re work capacity. You know how youngsters can get.

PSST! Found this site today: https://www.researchgate.net/publication/283086316_THE_SUPPRESSION_OF_COMMON_COUCH_GRASS_ELYTRIGIA_REPENS_BY_BUCKWHEAT

How did you get on Mary?
The couch (quack) grass on my allotment really took advantage of our full UK lockdown and now seems worse than ever.
I too, have nibbled it and found it palatable, but not as irresistible as John Gerard who proclaimed in his 16thC book that he'd rather eat couch grass than carrots.
I was a bit peeved to see that a piece had grown right through a nice spud when it got dug up. Should have just cooked it grass and all!

Hi , I did multi layers of cardboard and thick mulch.
Once the cardboard breaks down the cooch thrives.
Sits dormant waiting to hit the sun.
One year max in Victoria Australia and it's running rampant again.
Only way is to dig it out..I'm doing it now.
Nightmare job actually easier on areas I didn't mulch so much as it tends to grow along the top of the clay.
But in the thick mulched areas it's a bohemeth running all over the place thick white roots like spaghetti.
I sheet mulch every 3 years.
No grass property just natives and mulch.
Prob ok if a food forest but in my vege patch it just keeps popping up.
Dig it up and even then any bits left behind will take off.
Good luck ..hard yards = more fun.