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Eradicating Horsetail Grass

Hi all! Newbie gardener here! I wonder if anyone can help me?

Unfortunately, my garden has had horsetail grass growing in it for the past three years.

Initially I tried spraying it with weed killer, which didn't do anything! I then resorted to cutting it back to ground level, and spraying it, which killed the stalks I'd cut, but they were soon replaced by new growth.

Last spring I covered my garden completely with two layers of weed proof matting, and four inches of gravel, but the horsetail grass managed to grow up through the matting just in time for summer, so I was back to cutting and spraying again.

It's very frustrating as the horsetail grass engulfs any and all other plants! Short of concreting over my whole garden, does anyone have any idea of how to rid my garden of this incredibly invasive and annoying plant?



  • Hostafan1Hostafan1 Posts: 34,743

    really tricky one. The consensus seems to indicate walking over it to bruise the stems, then spray with Roundup ( glyphosate) Tough critter though. Might well need repeating


  • Hostafan1Hostafan1 Posts: 34,743

    I once read the roots have been recorded 300m , yes 3 hundred metres below ground which explains how it survived the last ice age. Don't give up though. If it's coming under a fence or boundary, you might ask your neighbour to treat his / her side too. In the end it's in both your interests to eradicate it. Good luck.

  • iGrowiGrow Posts: 183
    I am/was plagued with this on my allotments... After three years of intensive weeding ( I don't use chemicals) I have much reduced the problem on my original plot. I have only had the second plot for one season and am expecting the battle to recommence shortly... Let the stems grow a bit and then dig down as far as possible following the roots. The roots tend to snap easily so there is a bit of an art in how much pressure you exert. If the growth is allowed to get too big the stems snap and give off spores. Being vigilant is your best course unless you go the chemical route.
  • @Hostafan1 - Yes, I'd read about bruising the stems before, but that wasn't as effective as cutting them and spraying them. I guess the weed killer has to get inside the plant somehow! If the roots go down to 300m that's quite a lot of digging! image

    @iGrow - I know it spreads like wildfire if you try and dig it out and don't get all of the roots out of the ground. Like you say, it snaps really easily, so it's very easy to leave roots behind. My soil is very heavy clay too, which doesn't help matters! I think I'm going to have to go the chemical root again...

  • iGrowiGrow Posts: 183
    The soil I am working with is quite light so not too bad, I think I would go the chemical route if I had to contend with it in clay.
  • KT53KT53 Posts: 8,750

    This seems to have worked for me - hoe off at ground level and rake up all the bits.  Wait a couple of weeks for new growth and spray with Roundup or similar.  Wait until stems start to go black and hoe again.  Repeat the exercise a couple of times, so takes a couple of months.  Final hoe and cover over winter in weed suppressing matting.

    I've checked my garden in the past week or so and it looks pretty clear.  At least if it starts to regrow I should now be able to keep it under control.

  • djjjukdjjjuk Posts: 211

    one of the worst weeds you could ever have the misfortune of having. had it in my soon-to-be-previous garden, which incidentally is also a heavy clay, poorly drained and acidic. same conditions under which moss thrives.

    so, the answer from these set of circumstances would seem to be to improve the soil structure, as well as cutting any stems ground-level up before spore formation. now, these are very much long term solutions, but in my opinion are the only way. it will take some years to exhaust the root system of the horsetail but frequent cutting and prevention of above ground level foliage appearing will limit any new plants from being produced and will obviously exclude light and thus energy from getting to the plants roots, weakening them. it is not sensible to cut any root material, as not cutting a root cleanly will simply regenerate new plants.

    as for soil structure - dig in LOTS of organic matter. horsetail, as with moss, thrives in poor soil. i have read somewhere that the first plant to establish and grow on the burnt earth around the erupted Mt. St. Helens was ... horsetail! that in itself proves that theory. improving this structure over time strategically will help greatly.

    good luck ..



  • djjjukdjjjuk Posts: 211

    further to my post - just having done a quick google, came across this which is good information:


  • Thanks for the advice everyone! image

    @iGrow - Oh how I'd love light soil! 

    @KT53 - That is roughly what I did towards the end of last year, and it definitely killed off the top levels of the plant, but I'm not holding my breath about the root system! My horsetail grass didn't appear until about April last year, but I'm sure it will be back now that the weather seems to have warmed up a little...

    @djjuk - Having covered the whole garden in over six tonnes of gravel last spring, I don't think I'm up for removing it and digging in a load of organic matter to improve the soil structure just yet! I think I'm onto a losing battle if even a volcanic eruption can't shift the stuff! 

  • Autumn dhAutumn dh Posts: 51

    Djjjuk is the first one to speak sensibly about this stuff here. I'm surprised by how many threads suggest to add glysophate or Roundup. Are these advertisers suggesting this? It is just wrong.

    Anyway, I've been posting this on other threads because they all simply suggest weedkillers that are proven to NOT Work:

    We have this all over our lawn and garden. I've dug out the lawn as it was full of moss and horsetails. I guess this indicates how poor the soil is. The roots go far deeper than any herbicide will be able to reach. Glyphosate won't work. Glyphosate actually encourages field horsetail by eliminating competing plants. Horsetails love poor drainage, low oxygen, and acidic soil. You need to improve your soil by applying lime. After AT LEAST two weeks, apply horse manure. Then some nice compost. I've tried killing them with industrial grade vinegar (20%) but, like anything applied to them, it will only kill the tops and do nothing for the roots (which can go as far down as 7 meters...or over to Japan). Also, it acidifies the soil. Covering any parts of your garden with membrane or plastic will just make the roots really happy without the oxygen and horsetails will pop out everywhere along the sides. Don't do it. That's what the previous owner did here. You lift up the sheet of plastic and it is nothing but horsetail roots under there. They don't like shade so you can crowd some of them out with taller plants. From March to May you must be very vigilant and pull out any female (asparagus looking) horsetails as soon as possible as they spread thousands of spores everywhere. Do not till as it will make things worse. Every bit of root will regenerate into a new plant. We need to realise that they may never, ever fully go away. They take a lot of silicone from your soil so you can compost them after drying them out in order the replace the silicone. Try to improve your drainage by sloping the land away from your property and adding some ditches for the water to flow down. Some simply say it is best to pull out what you can and then just deal with them. The roots go so far down that they don't compete too much with plants for nutrients (allegedly) and the best thing to do is encourage them to move along by improving the soil. Very hard to do if your neighbour has them. Now that our lawn has been dug up, I've been trying to figure out what to do next. There are still tons of roots out there, but we're going to apply lime, then a layer of gravel to help drainage. Then manure, then some compost, and then turf. If anyone has any other would be much appreciated.

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