How to kill a cactus

In an earlier post, my mom asked for help identifying a cactus she has in her garden.  Ross came to the rescue, pointing out that it is a Cereus peruviana and a category 1 invader!  Needless to say, she now wants it out of her garden but if we cut it down with a panga we’re worried we’ll spread it around the garden and make the matter worse.

We also don’t want to use anything too toxic that would damage the environment and could get into the water table.  I’ve heard that you could use diesel but I’m not sure of the application and what the implications would be.  Any suggestions would be appreciated?

12 thoughts on “How to kill a cactus”

  1. The indigenous gardening course Rog and I attended last year touched on the diesel route. They suggested used garlon & paraffin or diesel. I have no idea what garlon is and if I am even spelling it right. Guess we should have asked. I’m not sure if I remember correctly whether it was a pesticide or could be used to get rid plants too.

    Why do you think cutting the cactus is going to spread it all over the show?

  2. Garlon and Diesel would definitely work. You can get it from most nurseries, and it has directions in the box. I’m not sure whether it would be spread easily if any cuttings (from chopping it up) fall on the ground, but just make sure that it gets dumped at the DSW site near makro – it’ll definitely be destroyed properly there. Personally, I’d probably skip the Garlon route and chop it myself?

  3. Niall dear, our garden service came this morning and when I mentioned destroying the cactus he told me that he had grown the same type and when it got very tall it fell over. His son proceeded to chop it and he ended up in hospital with burns from the juice. His workers won’t touch it and say even the smell of it makes your face swell.I’m waiting for him to bring me some poison.

    Love from your lovely mother

  4. I haven’t heard of it being poisonous? I think the fruit is even edible?
    Your garden service is probably confusing it with a Euphorbia, which has horrible milky sap which causes major irritation on skin and can damage eyes.
    The spines are probably the most dangerous part of the plant.

  5. Ja interesting point about the Euphorbia – we’ve got a huge one in our garden and a friend told us they are toxic and have a hectic sap and a total mission to get rid of. I worry about our one falling over because it is rather large… hmmm… Do you think gloves, goggles etc would be the solution when chopping down?

  6. Hi, guys
    Why haven’t you got some info from Working for Water? First of all, you need to correctly identify the plant. If jointed cactus of a sort, which one? The fruit and cladodes (flat sections) are edible, but the whole thing spreads too easily. If you chop it, the pieces will each propagate into new plants. We have experimented with specimens and some placed on metal sheets in full sun with no moisture are still alive and growing new sections after 19 months!!! All are horribly invasive and CARA Category 1’s. There is a biological agent we use in conservation areas, cocheneal, and if there is any other cactus in the area, the infection can spread, if slowly, and eventually kill other cactus. If you do chop yours, put it in a metal drum and pour on some parafin. Burn and make sure ALL is destroyed. Even one tiny scorched piece will regenerate.
    If local euphorbia, beautiful and great to keep if you can. Yes, they are toxic, even the honey made from the flowere can be a major health hazard.
    If you can, send me a photo and I’ll identify it for you. Let me know if you want more info…T

  7. I’ve found that it needs to be chopped out – especially if it is large. But it really needs to be done by someone with experience. Your local garden service guy is the best one to talk to – or maybe your municipality has a helpful removal service.



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