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Oxalis eradication

Posted by Maldonmarie Vic Aust (My Page) on
Wed, Jul 6, 05 at 21:02

I live in Central Victoria where oxalis just takes over at this time of year(aka soursob, the one with the bright yellow flowers on longish stems).
Each year I usually just pull it out before it flowers, but of course the little bulbs are still in the ground and it reappears the next year. I can't spray as it is mixed up with newly emerging aquilegias, love-in-the-mist, poppies etc,
Any other suggestions please?


Follow-Up Postings:

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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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


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RE: Oxalis eradication

I've been digging over the veggie garden and had a container handy to put all the bulbils that have been disturbed. As soon as I see one I stop and manually move the clods around to find the rest of the colony. Otherwise you just manage to spread them around by cultivation.


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RE: Oxalis eradication

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


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

  • Posted by meryl2 Sydney/Blue Mts (My Page) on
    Sat, Jul 9, 05 at 2:40

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!


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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!


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RE: Oxalis eradication

  • Posted by pos02 NSW Aust (My Page) on
    Mon, Jul 11, 05 at 20:52

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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
:-)))))


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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

Shelley


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

  • Posted by deejaus Melb.Vic. Aust (My Page) on
    Sun, Jul 31, 05 at 22:29

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


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RE: Oxalis eradication

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)


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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.


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RE: Oxalis eradication

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


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RE: Oxalis eradication

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


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