Oxallis eradiction

I have several trees with oxalis stricta (wood sorrel) infestations. I try to keep up by pulling it as it comes up but I cant keep up. Pulling by hand doesn’t seem to work, either the petals just break or if I am able to get the root to come up it disturbs to tree’s roots and top dressing. Despite constant manual work the weed never goes away.

Does anyone have any tips/tricks to eradicate this extremely vigorous nuisance?

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I’ve heard that certain weeds come up as a part of the soil trying to repair itself or because there is an abundance of certain elements. It might be a bit of a alternative/hippy way of looking at things but because of the importance of soil you might want to see if there is an abundance or the opposite some element that is lacking.

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Painting vinegar on the leaves can sometimes kill the roots.

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I’ve found this to not work too well on oxallis because the surface of the leaves are pretty hydrophobic. I have pulled the foliage and then painted the top of the exposed root if I’m not able to pull the carrot shaped root.

I had a huge oxallis issue, but it was mainly because I was lazy. This year I wanted to attack it head on. I started by buying a pair of tweezers, pulling each affected pot (aka all the pots) into my workshop, and pulling at each root one at a time with my tweezers. I called the main carrot root the “mother root”. You kinda have to grab the top of the root and wiggle back and forth. Most of the time it’ll eventually come out and then surprise you with how deep it went.

Oxallis will send runners that will eventually become mother roots if the they’re allowed to remain in the pot. Luckily those are fairly easy to get rid of. The mother roots are not. Sometimes I would not be able to pull the mother out at which point I would dab the top of it with a vinegar soaked q-tip.

I did two pots a day which surprisingly didn’t take too long. After that you kinda just go into maintenance mode. Everyday while watering just pluck the leaves as you see them while trying to pull the mother root. Eventually the top of the mother root will get fairly swollen since it’s had to keep creating new foliage. That makes it easier to either pull out by hand or with tweezers.

The main thing is that you DO NOT want to let them go to seed. When pulling the weeds I also just lay it on the bench to let it dry out. If you just toss it on the ground you’ll end up with weeds all around your bench and then eventually in other parts of the garden as it sends out seeds.

It really only took me one spring to get things back to manageable. Whenever it would rain I would walk the garden to weed since I didn’t have to water. If I was watering I’d just pull the occasional weed here and there.

Stay diligent and good luck!

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Excellent advice! Thank you!

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I agree with @Bonsai_Bentley that continuous removal is the best approach, but misting vinegar on a bad infestation can kick it back a bit until you can get it weeded.

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Why would i want to get rid of them in the pots? Meaning what detrimental effect do these have on the trees?

Thanks

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Hadn’t tried the misting approach. Mainly because I didn’t want to get any of it on the moss.

Aesthetically it’s not appealing. Horticulturally, the roots are quite large. You now have something in the pot absorbing nutrients and taking up space where fine tree roots should be growing instead. A random fern here or there is fine. Oxallis will quickly take over multiple pots if allowed to do so.

It’s the runners. They go far and usually along the edges of the pot where it’s nice and warm. Trees will want to put roots along the edges at first too, so I’d rather not have the competition.

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Here is an example of how deep their roots penetrate and how they can entwine with and take resources from the tree’s roots.

During this repot this last spring I tried to remove as much as I could but it still came back.

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Dang, look at those runners :weary:

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The struggle is real and kicking my butt

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I definitely had the most in my developmental boxes, but they’re now my easiest ones to take care of. I will say that it took multiple workshop sessions per dev box. Just take it one pot/box at a time and you’ll get it. It’s smooth sailing from there as long as you don’t let any of it set seed. 100% eradication isn’t possible though because the seeds are still in the surrounding areas. It’s just one of those daily tasks. I find that they often want to pop up right at the base of trees too which is quite difficult to pull and annoying to deal with. :rage:

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It requires patience and constant weeding. It is very satisfying, however, to pull a long runner out in one fell swoop. I love the contrast of the yellow flowers and the dark red leaves, so am considering adding one to my kusamona pots, although it may be a “mono” planting. :smiley:

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I agree but it also makes me nervous that I am interfering with the tree’s roots. I have pulled up a tree root a handful of times thinking I had found the main runner :sob:

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@Bonsai_Bentley thanks for the comment.

Glad i found the thread. This was the first year i had them in some pots. did not think much of it and actually quite liked them with the small flowers.
So, went in today and removed as much of it as possible. Yes, another year and it would have been a major issue for the root ball.