Question about Oxalis

Can someone please tell me how oxalis spreads? And how to get rid of it without resorting to RU? And how to prevent it coming back if I am successful in eradicating it? And why my lawn and gardens which were once so pristine are now full of it and bent grass and quack grass and pennywort and nutsedge? Actually... the only thing my yard doesn't seem to have anymore is regular grass. LOL (not really)

I think it is with little rhizomes and I just pull them to get rid of it. It worked for me.

Nature hates a vacuum! You have a bit of bare earth, sun and water; Mother Nature obligingly fills in the spot with a seed, a bit of root etc. Growing lawn grass is mono culture- growing just one crop in an area. That is actually hard to do. If you wish a pristine lawn or garden, you will need to be very involved with preventing weed growth and if that is not 100% effective, be very involved with weed eradication. Some proactive ways to prevent weeds from being a problem in garden beds include mulching, pulling out weeds before they go to seed, not composting weeds(may spread seeds if compost doesn't get hot enough to destroy the seeds) and keeping your plants healthy and full. Lawns benefit from pre-emergent treatment to prevent weeds from germinating, filling in (repair/reseeding) bare spots and a good fertilization and watering program to keep the grass healthy. Roundup will kill everything it touches so it is not suitable for lawn application and must be used with extreme care in garden beds. I hope this helps.

Oxalis is a huge self seeder. Its just horrible in my rock gardens. I gather yours
is in your lawn? I've only had trouble with it in my garden beds - it just loves growing
amongst my other pretties.

The active ingredient in RoundUp is glyphosate and although it kills a lot of things it touches, it definitely will not kill everything. It is totally ineffective against oxalis in my humble opinion. RoundUp QuickPro might work because in addition to glyphosate, it has Diquat as an active ingredient.

http://davesgarden.com/community/forums/p.php?pid=4021773

Oxalis is native to South Africa, Central America, and South America. Its reproduction can be asexual or sexual. I don't know which oxalis you have but pull some up and see if you spot a bunch of bulblets. If you have a bunch of bulblets in the ground, you've got a nice big problem and I'd suggest digging it all up if you are opposed to using chemicals. Leave one little offset behind and you'll be infested again.

I've got a big problem with Quack Grass myself.

What you described to me above going on in your lawn sounds tough. Would you consider starting over from scratch? You could try nuking everything by solarizing which would give you a clean slate. At least when you start over from seed, you'll know to jump on the first nasty that tries to rear its head in your lawn. All the nasties you described above should be able to be solarized effectively. You'd have to leave the plastic down for a lot longer than a few weeks though with what you listed out but it can be done. I've seen entire fronts of lawns around here with dark plastic down over them so you wouldn't be alone. People are trying their best to reduce their dependencies on chemicals particularly since quite a few plants are now becoming resistant to RoundUp.

Do some online searching for solarization of weeds and see what you think. It might be the most cost effective and environmentally responsible route for you to go.

I believe that it reseeds quite well. It is one of my most common shady or wetter area weeds. I have never used Roundup on it, selective herbicides will work fine on it, but make sure it's growing well and not wilting if hot and dry. Preemergent herbicides should give you some results.

Al, she's in CA not out by us. I just read an article that they're having big problems with a different type of Oxalis than what plagues us. Specifically Oxalis pes-caprae. No photo of what she's got there and to top things off, many people confuse Oxalis with Black Medic and a few others.

What do you think about solarization for what she described? That's the route I'm going myself only I'm doing small portions at a time so I don't end up with an entire acre of plastic.

I would agree that pre-emergents will help a lot with annual weeds once she gets her lawn back to being a lawn and not a patch of invasives jockeying for position.

Equi, that's exactly the oxalis I have. When I bought my house a couple of years ago there was none growing around me. Now it's everywhere - in the lawns, the garden beds, in cracks on the paths. I can only assume that the whole garden was nuked right before I bought the house and all the nasties have come back with a vengeance. Or it was carried in on a lawnmower when I had a lawn service.

I'm not opposed to solarization, although it will look a little odd on the front lawn. There are gardens around my neighbourhood that look like the oxalis has been grown as a ground cover, it's that prolific. The first search i did on the name took me straight to UC Davis' website. http://tncweeds.ucdavis.edu/alert/alrtoxal.html

Having thought some more about the solarization, I can see how I could work this to my benefit. I would love to get rid of the lawn and turn it all into garden but my DH is opposed to it. He has some weird desire to own grass. I could cover the front lawn, one side at a time, with plastic, then cover the plastic with an attractive bark mulch. I could purchase lots of large plant specimans and arrange them attractively on the bark mulch to resemble a lush garden (this would make it look attractive from the street). By the end of the solarization period he would have gotten so used to not seeing lawn (& having to mow it), he would have no objections to me planting all of these lush plants. he he he....

Can you wait to see what Al thinks? He does this for a living and my ways are somewhat biased because I'm trained differently. We pretty much are taught to avoid chemicals when ever possible (public health reasons as well as benefits to wildlife and the environment) and to be honest with you, that's not always practical when you have a husband who wants lawn.

yes, I can wait. I think it would be a job to start after the holidays anyway.