HELP Sheep Sorrel/Rumex infestation in my edible garden!

Dear readers,

If you know what sheep sorrel is, then I hope you haven't grown to know it as intimately as I have.

I'll make a long story short. I'm on 100 acres, yes the soil is acidic. Not too acidic, at the surface (maybe 5.5pH) but very acidic in the subsoil, around 3pH.

Our soil is actually the most beautiful clay, hardly believable that it is clay as it's loose, friable, free draining and red brown.

I didn't realised that there was sheep sorrel/Rumex all through the grass here, and we proceeded to excavate some large terraces which we have planted out with fruit trees and perennials to the east, and annuals to the north (we are in Tasmania, Australia).

I would have never started such an enormous garden if I had known about the sorrel (lesson learnt!) And it was already escaping me before having a baby.

Now I have a 6 month old and only manage about an hour of gardening a day (I was doing up to 8 hours a day before) and the sheep sorrel has infested everything. Yes I know it's an indicator of acidic soil.

I have spent quite a lot on the best possible compost I could buy, as well as us making our own and have been trying to balance the soil but nothing seems to help. I've layered 5 layers of cardboard with thick wood chip mulch but it just grows through.

Digging the soil over and over to remove the sorrel roots is destroying the soil and making it hydrophobic. It is so vigorous that it sucks up water from the plant I am actually trying to grow (and I assume nutrients too).

I've never hated 'weeds' until this.

Please someone help. I'd love to hear from anyone with any experience at all with this plant, or recommendations for what I should do.

The whole point of these terraces was meant to be lower input (in the perennial areas) and it's taking all my time. It takes forever to prep one garden bed.

I'd like to move on to other projects and just feel soo stuck!

Thanks for your input 😩

If you're patient, you can lay boards over it and deprive it of light. That kills it eventually. You could also try covering with cardboard and a deep layer of mulch, and then when it does pop through either chop and drop, or try to pull it. I'm getting rid of a few clumps this way...the mulch loosens the soil and I can sometimes get the entire root (I'm doing this to control dock as well).

In my case, I actually made the mistake of planting it in the veggie garden about fifteen years ago. Even worse, I let a plant set seed. Never again.

Julinka Arden wrote:Dear readers,

...sheep sorrel...
...an indicator of acidic soil.

Thanks for your input 😩

First of all, welcome to Permies Julinka and congratulations on your baby and your new gardens and orchards!

We also have clay soil here and had a lot of sheep sorrel.
Last June we got three ouessant sheep for keeping the grass short. I haven't spotted nearly as much sheep sorrel at the end of last summer as the summer before, now that I think of it. But I also didn't really investigate, I'll look more precisely into it this season! Perhaps the cure is in the name?
Could you let a few sheep graze over your terraces? Protecting the plants you've so carefully planted - my ouessants are a very small but primitive breed and they love to nibble at the bark of fruit trees, I've had to cage my trees.
Also, as sheep sorrel is an indicator of acidic soil, you might try dumping a handfull of chalk lime at the foot of each plant - and cut off any seed heads.
I hope these suggestions work for you.

I guess I’ve been lucky. I wonder if I’m setting myself up for future hardship by ignoring it. It grows lowish, so doesn’t shade anything out. When I find a particularly dense clump of it, I yank it up out of the mulch and take it in for the next meal. I kind of like having it around.

ETA: I'm on acidic sand instead of clay, if it matters.

I built my latest garden on the poorest part of our yard because it was a) flat and b) in full sun.  I made the mistake of keeping one sheep sorrel plant in the corner because it was scraggly like all the rest of the plants in that part of the yard, and because I like adding a few leaves to a salad.  Imagine my surprise when it not only flourished, but started appearing several feet from where that original plant was. It's taken many hours of pulling it up by hand and pulling out all sections of the roots I can find to get it under control.  I have no doubt it will start popping up again but thankfully the wood chips in the paths around the beds make it pretty easy to pull up.  

Congratulations on your new baby!  I'm finally getting my 10 year-old interested in gardening but it's still a challenge to keep her entertained enough to work outside for hours.

Hi Julinka, I think sheeps sorrel might be quite variable since mine doesn't tend to spread much, but I have a neighbour who cursed it. To be honest I quite like it  - I often pull a few leaves to munch on as I'm wandering round, and add a few to a mixed salad. If you could find a way to use it in quantity (not recommended in a diet due to Calcium lockup) that would be the ideal solution.
Interesting that it is more effective at surviving in a drier climate as mine is really wet! What a plant! Wow! your soil is even more acidic than mine! I suspect that the sorrel is just so much better at thriving in the acid soil that it has a big advantage over the plants you actually want. I think you may need to modify your expectations as to what you can manage.
I looked at garden organic and they say:

Control on arable land is through removal of the roots during cultivation combined with hoeing and hand-pulling to prevent seeding. A dressing of lime has a good effect.

According to garden organic it is quite happy in full shade growing even under bracken stands, so it is logical that is spreads under sheet mulching. It can root a new plant from a fragment as well as whatever seed banks are in the soil. If you are digging and leave a few bits you will end up with several few plants rather than just one. I think your best bet might be to select a small area where you keep it under control by digging every little bit out, and just chop and drop the rest when it is bulky enough to do that ('doing the work of the sheep' to paraphrase the great Sepp). The sorrel biomass ought to help the soil structure too in time. You'll hopefully find most of your wanted perennials will still be there when you have time to get round to them. You're at the tail end of the summer now? so you might get a bit of a respite from urgent gardening for a bit.
Is there anyway to recruit help for you at this time? I can imagine that trying to do too much and worrying about it is not good for you. There are a few permies threads on gardening with babies and toddlers:
https://permies.com/t/173004/Gardening-Baby
https://permies.com/t/63694/Favorite-Gear-Gardening-Babies-Kids
https://permies.com/t/172954/Garden-Baby-Explore
I hope this helps.

Thanks so much for everyone's responses so far.

Just to clarify, I have in the past dug every bed and removed every single tiny fibre of root (or so I thought) only to have missed a few and it comes back. Not exaggerating, it would take me about 8 hours per bed to do extremely thoroughly with my finger tips and tools. Now I don't have that kind of time, and knowing I'll miss a few anyway means I know it's a waste of my time, so I typically spend about 2 hours on each bed and plant it out at that 90% done point.
I have spent a few thousand hours at least doing this, yet I am still losing the battle 😫

For context, there are three terraces, each about 5+ metres wide, and between 45 and 80 metres long!
It's A LOT.
I do have some beds that haven't been infested yet.

I currently have mountains of cardboard, newspapers and mulch which will have to do for the infested banks where it looks to be struggling because it's dry and hot but no, it is trillions of roots with hardly and leaves.

I feel like I'm going to have to learn to live with it and chop and drop it, which I have already been doing in some areas. Hopefully ones day the microbiology changes to favour it less.

I have many hundreds edible plants in already so sadly cannot use animals to manage it for me.

I want to start more gardens but am scared to because of the sorrel.

I would absolutely love to have woofers to help, but we currently don't have spare accommodation to house anyone else here (still yet to finish out own cottage and kitchen buildings as we are building from out own milled timber).

Thanks to all those giving input and for the warm welcome, I've been listening to podcasts for some time but never posted on permies before so it's lovely to see other people in the world are doing similar stuff!

We have an amazing life, and love and eat incredibly well, are so healthy and strong, as is our young son who was born here. 100 acres is a lot of work without kids, I'm glad we both love hard work!
Honestly the sheep sorrel is my greatest stress and worry 😅

As Phil suggested, the sunlight has to be blocked in order to kill it.  If one leaf sees sunlight then all the cardboard and wood chips are in vain.

Sheep sorrel looks like something I might have seen on my property.

Have you tried eating sheep sorrel?  It is suppose to have a delicious sour flavor.

I have read that it contains beta carotene and is also used as a treatment for inflammation, diarrhea, fever, etc.

Sheep sorrel is also used as a dye because it is high in oxalic acid.  

I hope you will find the solution to your problem.

Julinka, please do not give up or abandon future plans due to sheep sorrel.  I eradicated what I could from one bed in the fall and covered that bed with at least 6" of chopped leaves.  I don't expect that will completely kill it but hopefully slow it down enough that I can get a handle on it.  I have noticed as the soil in my beds and paths improves, the weeds come up easier.  By all means try chop and drop if that is easier, but just remember to do it before it goes to seed.

Due to an ankle injury last year I didn't get my garden expansion completed though I left it covered with black plastic through the winter.  Now I know black plastic is definitely not a permie solution, but it was here and is still in good shape.  When I pulled it back I have a nice layer of brown sod on top and after the plastic comes off I'll will be covering it with cardboard and partially broken down wood chips.  I expect some quack grass, dandelions and possibly even sheep sorrel to survive, but hopefully it's a very minimal amount.

Anne Miller wrote:As Phil suggested, the sunlight has to be blocked in order to kill it.  If one leaf sees sunlight then all the cardboard and wood chips are in vain.

Sheep sorrel looks like something I might have seen on my property.

Have you tried eating sheep sorrel?  It is suppose to have a delicious sour flavor.

I have read that it contains beta carotene and is also used as a treatment for inflammation, diarrhea, fever, etc.

Sheep sorrel is also used as a dye because it is high in oxalic acid.  

I hope you will find the solution to your problem.

I have tried eating it, infact I've been eating it ever since I was a little girl. Yes very sour which I like, extremely high in oxalic acid so should be eaten raw in moderation, I don't even like to give much too my goats.

It basically regrows overnight from rhizomes, so if you pull the tops off, come back a week later and they have renewed. Being such a large area is what's making it an impossibility for me.

Nancy Reading wrote:Hi Julinka, I think sheeps sorrel might be quite variable since mine doesn't tend to spread much, but I have a neighbour who cursed it. To be honest I quite like it  - I often pull a few leaves to munch on as I'm wandering round, and add a few to a mixed salad. If you could find a way to use it in quantity (not recommended in a diet due to Calcium lockup) that would be the ideal solution.
Interesting that it is more effective at surviving in a drier climate as mine is really wet! What a plant! Wow! your soil is even more acidic than mine! I suspect that the sorrel is just so much better at thriving in the acid soil that it has a big advantage over the plants you actually want. I think you may need to modify your expectations as to what you can manage.
I looked at garden organic and they say:

Control on arable land is through removal of the roots during cultivation combined with hoeing and hand-pulling to prevent seeding. A dressing of lime has a good effect.

According to garden organic it is quite happy in full shade growing even under bracken stands, so it is logical that is spreads under sheet mulching. It can root a new plant from a fragment as well as whatever seed banks are in the soil. If you are digging and leave a few bits you will end up with several few plants rather than just one. I think your best bet might be to select a small area where you keep it under control by digging every little bit out, and just chop and drop the rest when it is bulky enough to do that ('doing the work of the sheep' to paraphrase the great Sepp). The sorrel biomass ought to help the soil structure too in time. You'll hopefully find most of your wanted perennials will still be there when you have time to get round to them. You're at the tail end of the summer now? so you might get a bit of a respite from urgent gardening for a bit.
Is there anyway to recruit help for you at this time? I can imagine that trying to do too much and worrying about it is not good for you. There are a few permies threads on gardening with babies and toddlers:
https://permies.com/t/173004/Gardening-Baby
https://permies.com/t/63694/Favorite-Gear-Gardening-Babies-Kids
https://permies.com/t/172954/Garden-Baby-Explore
I hope this helps.

I believe it is very variable as I've seen a plant of two in alkaline soil and it really struggled and doesn't spread. I think it thrives in acid soils, and where nothing else is thriving it overtakes and get mega strong.

I'm half in the mind to move my blueberries and other acid loving berries to these sections of my terraces so that at least there's more diversity. Then plant ground covers and hope they balance out the sheep sorrel in time.

I read that sheep sorrel is every possible place in the world it will ever grow (nearly everywhere but Antarctica) because it is so successful at spreading, there's no where new for it to go, it already is everywhere that is climatically possible for it 😂.

I thinks it turning the soil sour and keeping it sour, so perhaps diversity in plants and trying to establish them as quickly as possible may help.

It is Autumn here now, so yes I've nearly planted out all my cabbages, broccoli and cauliflower and then I can focus purely on sheep sorrel removal haha.

Thanks for your input and for the other baby related threads!

Nina Surya wrote:

Julinka Arden wrote:Dear readers,

...sheep sorrel...
...an indicator of acidic soil.

Thanks for your input 😩

First of all, welcome to Permies Julinka and congratulations on your baby and your new gardens and orchards!

We also have clay soil here and had a lot of sheep sorrel.
Last June we got three ouessant sheep for keeping the grass short. I haven't spotted nearly as much sheep sorrel at the end of last summer as the summer before, now that I think of it. But I also didn't really investigate, I'll look more precisely into it this season! Perhaps the cure is in the name?
Could you let a few sheep graze over your terraces? Protecting the plants you've so carefully planted - my ouessants are a very small but primitive breed and they love to nibble at the bark of fruit trees, I've had to cage my trees.
Also, as sheep sorrel is an indicator of acidic soil, you might try dumping a handfull of chalk lime at the foot of each plant - and cut off any seed heads.
I hope these suggestions work for you.

Hi Nina,

Unfortunately I can't use sheep for this issue as there are many hundred plants to protect which is close enough to impossible, I did however already do this on the very bottom bank where I set up electric fencing and they did chew that right down for me (it has since regrown). But yes using animals is ideal, thanks for that suggestion.

I have also tried lime, to no avail.

Though very good recommendations.

Julinka Arden wrote:It basically regrows overnight from rhizomes, so if you pull the tops off, come back a week later and they have renewed. Being such a large area is what's making it an impossibility for me.

I have a plant that I dislike immensely.  When I decided it had the best of me and decided to live with it, it no longer bothers me.  I see some occasional and pull it up though nothing like the several trash bags full that I was pulling up before.

My suggestion would be to tackle one small area at a time. Maybe where you want it gone the most.

Hello,
sheep sorrel also invited itself in my front garden on the second year. Uphill, very dry, windy, acidic clay.
First I removed the dying cypresses that owned the land before, then the garden transformed itself in a massive opium poppy field in the first year, and thereafter sheep sorrel conquered the land. I managed not to go to jail in the meantime.
I brought a scythe. Whenever I see it growing flower stalks, I cut it down to the ground ; around three times per year.
Two years forward, I have a nettles invasion. All that good sorrel mulch laid foundation for a very rich soil.
Nettles are scythed a little less often - I prefer them in soups or stir-fries. Sorrel is still present but reduced, and cut 2-3 times a year, assuming its duty of living mulch and as much as comfrey does in other parts of the garden.
And the whole place is becoming a little orchard, with fruit trees and shrubs scattered all over the place.
Hope it can help,

Oliver

You know the saying, Nature abhors a vacuum?

I think you are missing half of the solution. You’ve got the first half - removal by hand. But you’ve then left a vacuum which is happily and promptly filled by your nemesis.

I’d be asking myself if there’s a plant that fills a similar niche (acidic soil loving, shade tolerant, low growing, tenacious) that you wouldn’t mind having everywhere until it runs its course or fulfills it’s biological need in your landscape.

Once you’ve got a target list you can start introducing them into your sorrel spots. My two cents.

I don’t have any potential plant suggestions except possibly miners lettuce, Claytonia species. It makes a tender and lovely salad green and for me anyhow, grows on the same sort of spots as the sheep sorrel. Good luck! 🍀

I tend to eat all the sorrel I can find.  But I was sad to see it die off around our fruit trees.  I suspect it's the lime we put around the drip line of the trees each fall that did it. Sorrel hates lime.  Fruit trees love it (in our area).

Two other areas where it vanished are where we planted clover, mostly crimson and yellow.  Anywhere clover takes, sorrel is usually gone the next year.

And anywhere the chickens can get.

But that's in my climate. Yours may be different.  Maybe it gives some ideas?

I feel your pain - we have been going through the same problem with sheep sorrel in some of our annual gardens. I started a thread about sheep sorrel a while ago, there’s some good suggestions there. I’ve been meaning to report back on there with what has been working for us:
https://permies.com/t/254475/Sorrel-stop-strangling-garden

What has been working:
Getting as much help from others as possible.
Broadforking really well before planting, and getting as much of the root out as possible.
Then when plants start popping up, continuing to rip them out by the roots while the soil is still nice and aerated.
Even if you can’t get the whole roots out, ripping the tops off or disturbing it with hoeing often will weaken it over time. Stirrup hoes can be a quick way to go over in between rows often.
Putting enough space in between rows and plants to hoe easily.
Being observant and ripping it out wherever it’s starting to go to seed.
We’ve also been adding lime, wood ash, and compost.
Using potato as a pioneer crop on sorrel infested land. Hilling the potatoes seems to weaken it a bit, and when harvesting the potatoes we can ‘harvest’ sorrel roots at the same time.
At the end of next season I hope to report back that our efforts have worked. I think I’m seeing some improvement this year compared to last year’s disaster.  

This is all what I have been doing for annual gardens. If we had an infestation this bad in a perennial area then I’d be looking at what is thriving (other than the sorrel) and focusing on growing that, or managing it in a way that I can get at the roots and improve the soil for a few years, and then planting the perennials once it’s under control. Rye is a bit allelopathic and a mixture of that and vetch might be a good thing to sow thickly to try and smother the sorrel, then when it flowers, chop, drop, don’t disturb the soil and then put shovelfuls of compost here and there to sow your perennials in (or plant seedlings). I haven’t tried this, but will be harvesting the potatoes from the worst area soon and planting rye and other green manures there so I’ll see how it’s looking in spring.

When I took over the allotment garden with everything in it, the sheep sorrel was already there. I knew it was edible, so I was happy to have it. Next year I experienced what all of you tell here too: it had grown over a much larger space! Now I understood this 'nice edible groundcover' plant has long underground roots that pop up to make new plants!

Luckily my garden is not very large. I managed to pull out the sheep sorrel plants from all beds except from where it originally grew. I give it permission to stay in that bed, which is my 'stinging nettle bed' too, together with horseradish and raspberries (in the middle of the garden, not so visible to the other allotment renters around me). Yes, I know, this will keep me busy ...