Oh yes! I know this little blighter well! It is, along with onion weed, one of the worst weeds to get rid of. When you pull it out, even though you think you have the bulb, it leaves lots of tiny bulblets behind ready to take over (as you already know).
Seeing that you can't spray it and you obviously can't cover it with black plastic to cook it in the sun either, the only option you have is to keep weeding...everyday if you can. Even if you can't pull out all the bulbs no plant can survive forever without leaves...so just keep on getting rid of every bit you see.
The other option is to wait until your new plants are big enough to move...being careful not to transplant oxalis bulbs along with them...and then spray the area with glyphosate. You get best results when the oxalis is in flower and you will probably have to do it several times over a period of time.
I'm sorry...there is no easy answer.
Cheers,
Dee.

gee, thanks, Dee.:))))
I have the same problem here in Brisbane with the pink-flowered one and mine is all around my roses.
I get a yellow dust-sort-of-stuff on it, too.
I bet that's not good either.
Annie

Annie,
The yellow dust (if it is when its flowering) is probably pollen. Oxalis spreads by bulblets and seeds.
Isn't it a shame that something which is actually quite pretty is such a damn nuisance?
Cheers,
Dee.

You might try just applying weed killer with a paint-brush to the oxalis leaves though the bulbils seem to be unstoppable sometimes.

I have heavy clay soil so it just isnt easy to dig up the bulblets. I think I am going to resort to weedkiller as I am getting more and more each year and if I lose a couple of small plants in the meantime I will need to accept that. It has helped reading this thread.

Shelley

Hi Shelley,
Just remember that wind is the worst enemy when spraying...that's usually when other plants are affected, so do it on a still day. Also you can make a 'screen' of cardboard or newspaper to hold in front of anything that is a bit close for comfort.
Cheers,
Dee.

The yellow-dust-sort-of-stuff could be rust, to which oxalis seems to be very prone. So not only is oxalis next to impossible to eradicate, it's a repository of disease which spreads to your wanted plants. I hate it!

I've tried painting it, protecting nearby plants on a windless day, everything but nothing works. So I just have to keep pulling it out. Moving plants is not an option and the bulbils would be in the soil anyway.

I think the yellow dust that Annie mentions is the spores of a rust fungus that's specific to Oxalis. It reduces the vigour of the pink-flowered one (O. debilis) that's our worst weed in Sydney, but doesn't get rid of it. I'm pretty sure it's harmless to humans.

Some weedy Oxalis species spread by seed while some others never seed (at least in my experience) and spread entirely from bulbils. O. debilis appears to be the latter type, but I'm not sure about O. pes-caprae, the large yellow-flowered Oxalis or soursob, which I understand is the worst weed of southern States such as Vic and SA.

In my garden the little creeping yellow-flowered Oxalis (O. corniculata group) is the one that seeds itself everywhere from explosive pods. I am endlessly pulling it out of pot plants.

Thanks to all those who commiserated about my oxalis problem. I will just go on pulling it out. I'm not happy about using glyphosate anyway, as I believe the fewer sprays we can use, the better chance we have of keeping the birds, frogs, possums, lizards etc in our gardens. They were here before us!

I know that for onion weed a few drops of machine oil onto the bulb (where the leaves meet) will kill them. Maybe this will also work for oxalis - worth a try.

Qxalis is a persistant little mongrel. I have had success with a combination of approaches. I too use the weeding and digging out of any bulbets method and even painting on Glyphosate where possible.

I have mostly had success with what I call the smothering method. Yes you are going to have to dig up and replant any stuff you want to save (making sure you do not take the dreaded oxalis with you) but personally I reckon it is worth it. Use lots of newspaper, cardboard, plastic weed mat or anything else that will cut the light out from the soil surface. I tend to prefer a thick cover of newspaper with some leaf mulch on top. After a while (it may be a year) you can peel back the covering and with a lot of vigilance knock off the few survivors by digging them up or dabbing Glyphosate onto them.

It will work but it takes time.

I have tried that!! While the newspaper did cover and reduce them, it also stopped the water getting to my plants (cannas in this case) and after removing the paper, the oxalis is worse than ever , With our wet winter you can just imagine it!:-(((( even used it strong on the centre of the %****#@s and even ammonium sulphate as a solution stromng enough to kill everything else and still oxalis triumphs.

Just been out pulling the ********* stuff up by hand, but I noticed that where the patch of Bacopa has thrived in another damp area, there were very few Oxalis plants. So I am going to dig out some rooted bits and put them where I am pulling Oxalis out elsewhere. I have only planted seedlings and bulbs there but bulbs have come up through the Bacopa no problem. And it's a free solution to try
:-)))))

Annabel, seems like you did not keep the ground covered for long enough. It has definitely worked for me. Where I need to water plants, I leave the odd cleared bit and either weed there or paint them or just lift the covering to water. Patience will get a successful result.

I still feel that if you try the combination approach you will eventually win, but it does take time. Sometimes years. Whatever works for you, by all means use it. I use the same method for onion weed. I know others that have used old carpet very successfully. It is really a case of improvising, knowing that the objective is to starve the plantlets of light.

Ditto to everything Robert has said...especially patience!
Cheers,
Dee.

I read a niffty article on getting rid of oxalis in a magazine - they recommended to fertlize it out!! Some good regular doses of dynamic lifter where suggested. I tried this in one small garden bed last year and it certainly knocked it around - didnt grow no where as well as it used too. You would probrably have to do this for a few years in a row to get rid of it completely.

I read a similar thing once...the difference was that it said to fertilise with urea, then when the growth spurt started, would be the ideal time to hit it with glyphosate.
Cheers,
Dee.

Dee, I am sure that is the thinking behind the use of fertiliser. Forcing as much top growth as possible creates a plant much more vulnerable for when Glyphosate is applied.

It is similar to another method I have observed. A friend applies liquid Nitrogenous fertiliser and then covers the ground with plastic and cardboard as well as. This forces the top growth even more. The cardboard goes over the plastic so that the Plastic does not "cook" the shoots. At least a week or so later the shoots have lept away and the Gyphosate has much more of the plant to absorb into.

They swear by it.

Wouldn't all that fertiliser kill any natives nearby? That is my worry.

Shelley

Hi Shelley,
I agree that it might be a concern. I guess each situation is different and people have to make their own choices and weigh up the risks and benefits associated with that choice. There is hardly ever an easy answer to problems (I guess that's whay they are problems lol).
Cheers,
Dee.

The main objective is to force the top growth so you really should not apply a balanced fertiliser (containing dreaded Phosphorous). You need only apply a nitrogenous fertiliser such as Urea or Sulphate of Ammonia. That way you shouldn't do any harm to native plants. They are both acidiying as well, so will not detrimentally alter the pH either. They are also rather soluble so they will not hang around for too long.

Thanks Robert...I should have realised that. Another one for the Grey Moment diary, lol.
Cheers,
Dee.

Has anyone tried any other weed killer than glyphosate with success? I have used all the others methods suggested in this thread except for the fertilize then poison method. I cannot rid my beds of oxalis but can slow it down. Sifting the soil of the bulbs actually works best and can be therapeutic but I can't dig up every bed. A product called "Image" was suggested to me. Any thoughts? Thanks
(I am glad to find others who find this plant bothersome. It is the bane of my existence. My first husband suggested I learn to live with it but it would just take! I also don't live with him any more LOL)

Apparently chooks dig out onion weed bulbs. You can make a simple A frame with wheel on the end, covered in chicken wire with an open bottom and keep a few chooks in it. When they've finished a patch, wheel it to another patch.

I've been noticing a patch of oxalis (yellow flower) getting bigger each year in the lawn here in Central Victoria. I read that Metsulfron (Brush-Off, now beyond patent and now cheap) applied at the right time works well. I have tried it and it looks promising. The time is when flowering (winter) and the Metsulfuron actually passes to the bulbils and kills them at this time. I sprayed it 2 months ago and it has taken 6 weeks to die off and has left most lawn species ok (grasses etc) but not some other things in the lawn. It's a pretty rough "lawn" actually. It won't be till next winter that I will know that it has worked fully. The amount of Metsulfuron needed is quite tiny. It is supposed to be one of the less nasty of the hi-tech chemicals, but it does last for some time in the soil, so I'd not use it in a veggie patch.

It has not been mentioned above but I am sure you very knowledgable people are aware of the Weeding Wand.

We don't have the same problem as you here in SEQld but I use the wand on various other pests, loaded up with Glypsosate.

Quicker than a brush not so dangerous as spray.

Commiserations,
Nod

This is an old post, 2005 it started! I use (spray) Zero 490, takes care of it. The only thing it has some difficulty with is Wandering Jew (or W. Dew) to be politically correct these days. It also battles against onion weed, digging out every seed really is the only way to get rid of that. Or simply sell up and move.
B

I am johnny-s mentioned above with a new login i think! The metsulfuron has worked perfectly. No trace of oxalis in the lawn. Minimal damage to some lawn species (a rough lawn with all sorts of blow-in plants in it, Grasses all ok.

I have this pest in my garden (the yellow variety) and I've noticed something odd. The garden bed is beside the house and part of the bed is very dry because it never gets wet when it rains. Would you believe that nothing grows in the shaded area, not even oxalis. Now it seems to me that if I can stop the rest of the garden bed getting wet that the oxalis will dry up and die off.

Does my logic sound feasible? I was planning to cover the infected area (is that the word) with black plastic and hold that down with bricks so that it cannot move. I'm prepared to leave it like that for years if necessary. I live in Western Victoria.

A

That will work but it won't be from stopping the rain. Water spreads through the soil, especially if it has low sand content. You'll also get condensation under the plastic which will drip back down onto the soil. What works is stopping the plants from photosynthesising which is what the black plastic will do. The plants will finally starve and die. It will work better if you water the area under the plastic (at night when there's no sunlight) to get the plants growing and using up the food reserves stored in their tubers. I've done that sort of thing and it works well. Just keep in mind a lot of plastics will perish in the sun after a while.

what if I cover the plastic with mulch? Would that stop the plastic from deteriorating?

Anything that blocks the UV light from hitting the plastic would extend its life. I did it with a Bougainvillea stump cut down close to ground level. Took it just over 3 years before it 'gave up the ghost'. I think Oxalis would be long term as well.

Thank you tropicbreezent

We could do with a little tropical breeze here at the moment. It's friggin' freezing.

3 years doesn't phase me as I've been looking at the pest for at least 3 years wondering what to do to kill it. I might give it a dose of sulphate of ammonia now and again to hasten the process. If I cannot get rid of it I will just turn the plot into grass and just mow it.

Plants get their main food supply by photosynthesis (at least 99.99% of them do). Fertilisers are like vitamin boosters, they keep the processes running smoothly but don't actually feed the plant. Cut off the sun you cut off the photosynthesis you cut off the food supply. Oxalis has tubers/bulbs which store up a lot of food reserves so it could take a while to diminish that source. So any fertiliser you supply the plant with 'winds it up' into high activity causing it to burn itself out faster.

My commiserations on your weather but we've been getting below average temperatures here as well (in Darwin). So sorry, no degrees to spare :(