Doubts about Clover -- Oxalis pes-caprae

Hello everybody

I am in Denia, Spain (zone 10a), starting the first phase of our syntropic farming project. I talked about it in the Mediterranean forum.

My concern with cover crops is this: I have clover growing all around. I know clover has good properties for my soil, but I have some doubts.

I planted 5 vegetable beds. Besides whatever I planted (peas, chufa, lettuce, whatever) I have clover growing. Also, between all the threes that I planted, I sowed more and more tree seeds (that is part of the method). But also part of it is now covered with clover.

Clover here uses to grow at this time of the year and dies around May. And my question is: it is bad for the other seeds or I should just let it be part of the game? My instinct told me to weed the clover growing in the veggie beds, and I did some of it, but today I take away 10, tomorrow I have 30. With the tree seeds, I take away part of it. But I find it like a nonsense battle, clover is faster than I am.

So, shall I let it live together with all the other things, is it beneficial? Or is it a red flag?

Picture of the clover growing around

Update:

I had a problem with translation, as here people call this “trebol” wich translates as “clover”, but it is not proper clover, is “oxalis pes caprae”

I personally consider weeds like your oxalis winter ground cover. Here we have dead nettle, so called because it has no stingers. It grows during cold weather then then flowers and seeds in May and is dead by June. If I want to plant earlier or reduce seeding I can cut it and leave it in place for mulch. Larger seed plants and vigorous growers like kale will simply out grow it and benefit from its soil cover when it dies back.  Remember soil life benefits from the sugars of living roots and decompose the dead roots so having a self sowing cover crop that dies in summer is very beneficial.
I cultivate my vegetable  garden with a chicken tractor so they eat it down and redeposit it as a fast acting fertilizer.  In my perennial berry rows it inhibits the sprouting of grass that will clump and crowd out the crowns. The plum trees that shade the berries are happy with anything that is shallow rooted that protects their roots from summer sun.

I will let the experts give you the professional polished answer, but here is my experience. I used to let that plant grow because, like you, I thought it was a helpful clover. Once a master gardener friend explained that it was not in the clover/pea family (plant family most recognized for having nitrogen-fixing bacteria associated with their roots) and was not the help to the soil I thought it was, I began aggressively removing. It's a prolific reseeder and has a high oxalis acid content in the leaves. I don't yet have farm animals but I believe plants with high oxalis acid content are toxic to certain critters.

Hans Quistorff wrote:I personally consider weeds like your oxalis winter ground cover. Here we have dead nettle, so called because it has no stingers. It grows during cold weather then then flowers and seeds in May and is dead by June. If I want to plant earlier or reduce seeding I can cut it and leave it in place for mulch. Larger seed plants and vigorous growers like kale will simply out grow it and benefit from its soil cover when it dies back.  Remember soil life benefits from the sugars of living roots and decompose the dead roots so having a self sowing cover crop that dies in summer is very beneficial.
I cultivate my vegetable  garden with a chicken tractor so they eat it down and redeposit it as a fast acting fertilizer.  In my perennial berry rows it inhibits the sprouting of grass that will clump and crowd out the crowns. The plum trees that shade the berries are happy with anything that is shallow rooted that protects their roots from summer sun.

Thanks Hans! I investigated on it. Here in this area, they call this thing “trebol” or “agret”. I’ve read on it, it is beneficial for fruit trees, good for water retention and fighting bad weeds. It has interesting properties BUT one of the bad things is that it can prevent some seeds to grow.

So solution is easy: look out where there are seeds to protect, and protect them. In the other parts, just leave it there. I took it away where the distance to my “seeds to protect” was less than my hand span. And periodically I will repeat the operation, and that’s it

I merged your stuff with the following thread. I hope that is okay by you.

I’ve read this article trying to find a solution to my “oxalis problem”.

https://agendagotsch.com/en/the-syntropic-value-of-grass-goodbye-herbicide/

As I wrote in other post, I’m having “agret” (similar to clover, oxalis pes caprae) growing everywhere. Around my trees is not a problem, it will die in May and I can use it as green manure.

But it comes to my veggie beds and that is a problem as it outgrows everything. It is impossible to fight, I keep weeding , but I end up hour taking it out manually. It is boring, tiring and frustrating.

This article says: plant grass strategically between vegs, so weeds want grow and it might give another kind of benefits. Anyone tried it? What do you think?

I cant combat oxalis, so I should use new tools. Because it is unsustainable for me to spend hours weeding it

I love mulch to keep weeds down. Grass sounds like it would be a weed itself.

Antonio Hache wrote:I’ve read this article trying to find a solution to my “oxalis problem”.

https://agendagotsch.com/en/the-syntropic-value-of-grass-goodbye-herbicide/

As I wrote in other post, I’m having “agret” (similar to clover, oxalis pes caprae) growing everywhere. Around my trees is not a problem, it will die in May and I can use it as green manure.

But it comes to my veggie beds and that is a problem as it outgrows everything. It is impossible to fight, I keep weeding , but I end up hour taking it out manually. It is boring, tiring and frustrating.

This article says: plant grass strategically between vegs, so weeds want grow and it might give another kind of benefits. Anyone tried it? What do you think?

I cant combat oxalis, so I should use new tools. Because it is unsustainable for me to spend hours weeding it

Apparently there are hundreds of types of oxalis and only a few act invasively. I wonder if you could replace it with a better variety.

We have what we call wood sorrel at our place. My kids rip it up by the handful and eat it raw. I drop a handful in when I am making soup.

Is the problem the solution?

I have dichondra as ground cover in one garden bed. It does incredible at keeping weeds away. If you’re transplanting it’s even better. Unless it’s early season direct seeding is more problematic.

there are way more kinds of grass than kinds of oxalis! i didn’t read the article, but i’d think you’d have to be pretty careful not to pick a grass species that would be as bad or worse than oxalis.

Most weeds grow where there is insufficient available calcium in the soil, or sometimes calcium and phosphorus.

I like to cut tall grass to use as mulch in my berry rows and vegetable beds. The grass seed often sprouts from the seed heads on the grass stalks.  It seems to be beneficial to feed the organisms breaking down the mulch and the soil underneath.  If left too long it can get firmly rooted but if the mulched is disturbed to break contact with the soil as it dries the grass dies adding more green energy to the mulch.  This process also suppresses the annoying cleaves which are sprouting in my mild winter and will climb my vies and trees. It is easier to just move the mulch around than trying to get a hold of individual cleavers and pull them or hoe repeatedly.

I merged your stuff with the following thread. I hope that is okay by you.

Cool! It inhibits sprouting! The camphor tree also inhibits seeds from sprouting,  so after it dies a seed bank has built up under it from birds sitting in it's branches and pooping. This seed bank then sprouts all at once, like a human-planted food forest, and apparently takes off quickly.

Thanks to everybody for the replies. Oxalis Pes Caprae is so intense that I decided to play with it and live with it.

In the vegetable beds I tripled the density, to leave Oxalis Pes Caprae without room to grow. It is working.

Around trees and seed cocktails I just cut it with a tool (dont know the name in English) , so it allows sun to come and also it weakens the bulb

Lets see how it goes

I have been researching a lot about this.

And well, it has NO solution for my situation.

Oxalis Pes Caprae expands rapidly by bulbs. As it grows where I have seeds, I can’t attack it. The subterranean bulbs keep on growing in Fall, go to dormancy in May, come back again. If you work the soil, they expand even more.

I cant cover them with cardboard or whatever, because that might kill the other things. Of course, no herbicide for the same reasons.

I’ve read that one way to overcome them is to tear them again, and again, and again, to weak them, and that might kill them on the long term. But that can take YEARS. That, combined with heavy seeding the area, so at certain point, my stuff will beat oxalis and it will not have room to grow. So, weaken it by tearing , and overseed the soil and win the race for the land.

As it grows in between my things, I cant be aggressive weakening it. I have to walk around the place and manually remove it. I spend a ridiculous amount of time doing that. But it has to be done, oxalis pes caprae is selfish, it takes a lot of resources and if it grows it keeps all the sun.

The paradox is, if you have trees, and your focus is based on trees, is a nice ground cover, very appreciated by citrus owners in this area. But if you want to grow things by seed, you need to keep it away and repeat, and repeat, hoping that this strategy will make room for your guys (seeds) to grow.

That’s it!

Last sunday I was told by a couple of old ladies that oxalis also turned the soil acidic (the oxalic acid it produces). Well, not really a concern in a mostly calcaric land, I should say. But they wanted the oxalis removed, anyways.
My crops that are taller than the oxalis leaves don't seem to care.

Hi Antonio, maybe you could try covering it with a 5cm (2 inch) layer of woodchips and what peeps through there keep chopping it off. Or people have these sandwich techniques, cardboard, straw, compost, cardboard again, straw for looks. Put stones on the side to keep it from blowing off. Then plant some things that get really big and produce shade, like cardoon or artichoke or purple headed brocolli.
Or create a physical barrier between big shading plants and the invaders. Like dig a hole and put in a plastic pot without the bottom and fill that with nice soil and a plant that will grow big. Something like cardoon or artichoke or some type of purple head brocolli or some creeping cherry tomato that towers above or a dense mini forest of giant palm kale. I am just mentioning these plants because they grew really big at my place and "light suffocate" evil spreading stuff under it. And because they are there all winter, they don't mind a bit of night freeze (we have that), they grow all winter.
I think winter where you are might be exactly the time this kind of bulbil loves, enough water around, the leaves of the trees fell of, so enough light, suck up all the light, suck up all the water, suck up all the nutrients from the fallen leaves and make many babies, happy, happy time and comes summer, just hide in the bulbil and wait it out while everything you have planted suffers and dies from heat stroke and drought. Just to feed more oxalis.
I know you've thrown many seeds around, so you might lose those with the sandwich technique. But if they don't grow because of oxalis there is no loss.
Anyway, here's hoping these are some ideas for the future.

Abraham Palma wrote:Last sunday I was told by a couple of old ladies that oxalis also turned the soil acidic (the oxalic acid it produces). Well, not really a concern in a mostly calcaric land, I should say. But they wanted the oxalis removed, anyways.
My crops that are taller than the oxalis leaves don't seem to care.

So, maybe not good for mulch either

Hugo Morvan wrote:Hi Antonio, maybe you could try covering it with a 5cm (2 inch) layer of woodchips and what peeps through there keep chopping it off. Or people have these sandwich techniques, cardboard, straw, compost, cardboard again, straw for looks. Put stones on the side to keep it from blowing off. Then plant some things that get really big and produce shade, like cardoon or artichoke or purple headed brocolli.
Or create a physical barrier between big shading plants and the invaders. Like dig a hole and put in a plastic pot without the bottom and fill that with nice soil and a plant that will grow big. Something like cardoon or artichoke or some type of purple head brocolli or some creeping cherry tomato that towers above or a dense mini forest of giant palm kale. I am just mentioning these plants because they grew really big at my place and "light suffocate" evil spreading stuff under it. And because they are there all winter, they don't mind a bit of night freeze (we have that), they grow all winter.
I think winter where you are might be exactly the time this kind of bulbil loves, enough water around, the leaves of the trees fell of, so enough light, suck up all the light, suck up all the water, suck up all the nutrients from the fallen leaves and make many babies, happy, happy time and comes summer, just hide in the bulbil and wait it out while everything you have planted suffers and dies from heat stroke and drought. Just to feed more oxalis.
I know you've thrown many seeds around, so you might lose those with the sandwich technique. But if they don't grow because of oxalis there is no loss.
Anyway, here's hoping these are some ideas for the future.

Hola Hugo!

I think that for this year, the only way is by hand. I cant risk everything, so I should go again and again and pull the thing out.

Next year it will emerge weaker, and I will be faster working on it. With other things growing, in a couple of years it should be a minor problem

Fun fact. While I was digging my new bed, I found oxalis bulbs at 30 cm depth. They look like small chestnuts.

I'll keep doing what you are doing now. Just remove their leaves where I want seeds to germinate. My terrain is so full of wild plants, that I don't think I can manage them properly without chemicals. More than weakening them, I just want my plants to have room and sun.
We had a plan for replacing this invader with other more gentle cover crops, but insofar we haven't acquired the right seeds (we are mananging the garden with zero to none expenses, so we are relying on contributions from local donors), legumes and gramineae is a good combination (we thought on lentils + sorghum).

The way of the old ladies is to remove them completely, with chemicals or rototillers, and leave the soil exposed to erosion. But we don't want that.

Where I live (Los Angeles, CA, USA zone 10)  This type of Oxalis blankets the hills. It definitely inhibits the germination of many types of seeds. And it seems to have an allelopathic impact on many plants growth.. In my yard I removed the top 1 foot of soil and threw it away. This removed most of the bulbs/corms. It does not produce from seed, only by corms multiplying and spreading underground.  My soil is slowly recovering and improving after a lot of amending, compost and mulch.