I'd be pretty careful if I were you. Weed B Gone is only selective with regards to monocots (grass-like plants). Cacti are dicots so subject to the same mode of operation of the herbicide as would be any other broadleaved (dicot) plant. Also Dicamba, a primary ingredient of WBG, is known to have deleterious effects on some cactus species.

I'd probably opt to paint on the stuff rather than spray. And very carefully at that.

Thanks for your reply, gardengal, but I need to come up with an easier way.

Painting is out of the question. The oxalis is on the edges and long spines stick out.

There is also over a thousand to do, so it would be more time consuming than the golden barrels are worth, I have a Wholesale Nursery. I might be able to wait until the barrels dry out then sprinkle over some Freehand granules to stop the weed seeds from germinating.

Someone made a comment that if the herbicide was used half strength, the cacti wouldn't get hurt as bad, as the oxalis. Some buyers won't buy the cactus or succulents, if they are contaminated with oxalis.

Maybe there is another product that can be used, or someone has other ideas.

I really don't like using chemicals, but sometimes I have no choice, Thanks again!!

I just saw this tip on TV last week, seems worth a try.

Try spraying the weeds w/ straight vinegar, supposedly its acid will selectively kill the weeds but not the surrounding plants, so I'd give it a try. Safe & cheap enough to check out, I'd think.

Oxalis is a dicot and so is the cactus, so anything you spray that could kill the oxalis would damage the cactus.

Is it creeping wood sorrel that you are having a problem with? Oxalis has a bulblet that makes getting rid of it very difficult.

I would consider thoroughly clearing an empty section of land of weeds with grow kill cycles of herbicide, lay down weed barrier everywhere you can, bareroot the cactus to make sure the bulblets are eliminated, and then replant in the cleared land. That should let you control you oxalis with preemergent.

Or consider barerooting the cacti and growing them in Missouri gravel beds. Weeds seem to be a lot easier to control in gravel, plus you'd be able to easily sell the plant bareroot. You'd be able to examine the rootball for any bulblets.

The oxalis is creeping has a clover leaf, and gets very deep rooted around the cactus and succulents. I'm going to test the vinegar idea on a few samples. I'm growing in pots, because I ship to California and have an ORR certification from the State of Arizona. The plants can't touch the ground, they are either on benches or weed barrier with a couple of inches of washed gravel. I really appreciate the help I have been given. If I let the oxalis dry out will that kill the bulblets also? Do I need to take over 1,000 golden barrels out of the pots clean the oxalis roots and bulblets off each plant ?? Then repot them again, sounds like a lot of work, wow!

Vinegar is NOT safe for the cactus! It is a non-selective herbicide and has the potential to kill anything it touches, although larger plants may not be as affected as readily or as easily as smaller ones. And really, that is going to be the same result with any type of herbicide you use - if it successfully kills the oxalis, it has the potential to kill or seriously damage the cacti as well.

Bare rooting them and clearing out the weeds seems like your best and safest bet. Yes, it's a lot of work but running any kind of large scale growing operation generally is :-))

IMO Growing plants is like Christmas morning, there is always another present. Seeds are sprouting, cuttings show roots, seedling leaves break the soil surface, buds break into flowers.

I guess I need to see a mental doctor for getting into this at the level I'm at now. Sometimes I wonder if I'm making any profit at all, with all the expenses, and unforeseen problems that arise? When I talk to other growers, they don't like to give out any helpful information to their competitors.

I would like to thank again the few members who have tried to help and share information. These are the people that keep me thinking positive in this business.

Bare rooting 1000 golden barrels seems inconceivable to me. And oxalis is capable of withstanding long periods without water since they're corms. I was once given a small sack of corms, forgot about them in the sack in the garage for almost a year and most of them flushed out when planted. Plus, you'd need to completely remove and replace all the soil since the oxalis corms tend to hide out very well when they're small. The bite that would take out of your profit margin probably isn't reasonable.

WBG also functions, though at lesser level, through soil contamination. The half life is pretty short in rich soil with lots of biological activity, probably much less so in a cactus type mix. My preferred herbicide is glyphosate. It is only effective when foliar fed and will not impact a plant through the roots. You can dump a gallon on the soil around a plant and nothing will happen to it.

WBG functions by causing very quick growth that outruns the plant's ability, causing failure. Glyphosate works by shutting down the metabolic functions of the plant, so it starves. So, you may see a rapid growth spurt with WBG before it dies, leaving a lot more dead plant material in the pot, which may be more unsightly if you want to market them soon.

I use a sheet of cardboard, a flexible plastic cutting board or an umbrella to shield the desired plant from overspray. But you can use anything handy. No need to leave the shield in place, you can just move it along with you. The amount that can transferred by touch has never been an issue for me. I always add a tsp of dish liquid (original Dawn) per gallon to function as a surfactant, add an extra ounce of concentrate than prescribed (particularly for tougher weeds like Bermuda, nut sedge, etc) and only apply during dawn or dusk and when wind is calm since glyphosate is only effective in liquid form and sun/ wind will quickly dry it. Plus, wind will blow the spray around, increasing threat to nearby desirables. Rewetting does not reactivate.

I've used the generic glyphosate made by Eraser, which is a higher concentration (so, much cheaper per diluted gallon) but for some reason does not show results nearly as quickly. So I prefer good old roundup, results can be seen in about 3 days verses 2 weeks.

Keep in mind that not all corms will be foliated, which means they won't be treated unless they're still attached to a foliated corm. So you may need to treat, then to water when your cacti are ready for watering in order to call out additional corms and treat again. Same with any seeds lying around.

Sounds like a big job. Good luck.

Vinegar is just going to burn the topgrowth down. The bulblets will resprout. You would have to hit them with vinegar (or any other non-systemic) until the energy reserves of the bulblet are exhausted.

Idk if a shield will work dorkstenia. The weeds grow up from under the barrel in between the barrel and the spines.

And you can use the lure of 'plants as pay' for those volunteers who want to expand their collections - send them home with a few GBs after they've spent hours depotting, removing the corms (?), then repotting (although I really like, and your plants really like, the idea of open planting, since they're taking up that space anyway).

I was going to recommend the shield as well - cardboard works great, although for as many plants as you have, I'd make something more permanent in sheet-metal / aluminum. I don't know of a organic replacement for Roundup, but I think there is one. Don't use Roundup, please - the earth and I thank you. Glysophates are very bad news, and Monsanto is corporate evil.

Yeah, if the oxalis is growing out from against the barrel in a typically sized nursery pot for a barrel, it would be almost impossible to shield the cacti while effectively treating the weed. I would think it would take months of actively and constantly removing foliage to exhaust the stored energy. It's such an undertaking anyway you cut it.

I second the suggestion for reaching out to local schools. I'm sure there are professors that would love an opportunity to take a class on a trip to evaluate a large growing operation. It may take a while to orchestrate, however, since semester curricula are already set for the semester.

And perhaps even an ad requesting volunteers in exchange for plants. Facebook might be a good social network to find people interested. Throw in some BBQ and beer and you might have a good crowd, but volunteers require quite a bit of oversight.

Cactusmcharris, we'll have to agree to disagree. I find glyphosate to be an extremely effective and safe herbicide. It has a lower LD50 than table salt and is far more effective and less toxic than many organic alternatives available. I also admire the advances in biotechnology and agritech that Monsanto has provided and know of no 'evil doing' on their part. Yeah, I'm one of those ;).

Fun fact: although Monsanto is the largest global seed (conventional and organic) producer, it is only the 5th largest agrochemical producer with a mere 10% share of the global market.

I guess there's no easy way, other than pulling the oxalis. This is a good lesson because anytime I pot up plants I'm going to use a preemergent in granular form on the soil surface. It's no fun putting a few years in growing a thousand plants, then getting them contaminated with weeds. Unless you get volunteer help, the labor is more than the plants a worth. IMO prevention is the way to go. Again I appreciate all who have tried to help, I can use all I can get. Growing plants seems to be a never ending learning process, Thanks!!!!!

The variety of oxalis that has bulbs (buttercup oxalis) has sterile flowers, but may leave tiny bulbs in the soil even if you pull out the plant. The oxalis that creeps along the ground, creeping wood sorrel or oxalis corniculata, reseeds vigorously and often hitches a ride in nursery stock. There's no easy way to deal with either one.

oxalis IPM