Topic: Horsetail in my new garden

[Galette]

I see this horrible stuff growing amongst the plants in flowerbeds and rockery areas. How can I get rid of it? I'm prepared to be ruthless. Has anyone been successful in eradicating this weed from their gardens?

[BarriedaleNick]

It's a mare (gardeners joke!) - Even roundup won't kill it as it wont penetrate.  However if you are happy to use roundup or similar the advice is the scruntch the plants up a bit to damage them and let the weedkiller in.

[hippydave]

You can make the weed killer penetrate the mares tail by adding an adjuvant that breaks down the waxy coating of the plant. I use a product called Pearl but it is a professional product and should not be available to the general public. This is a specific mare tail weed killer but it still takes around 3 applications to eradicate it. Ideally you could do with finding someone local who has their PA6 spraying certificate to apply it for you. The only down side is that this is also a total weed killer and not selective and will kill any plant it comes into direct contact with.

[nodig]

You can't dig it all out in one hit because of the depth of the roots and the way it breaks so easily when you pull it.  With spraying I hit it at least 3 times with a couple of days between each application and scrunch it with my boots at the same time to give it a headache. If you don't attack it you will soon have a field of horsetail waving in the wind, blowing spores further afield.  Make no mistake Horsetail is a menace and its spread should be of concern.  If I dig out roots I leave them to dry up and die in the sun.  If you pile them up in some corner of your plot and then perhaps take them to the council green waste recycling, I wonder if the roots will end up invading another location if not carefully processed.

[squeezyjohn]

If it's in a bed that doesn't have anything else you want to keep, ammonium sulphamate will kill it.  Ammonium sulphamate is technically illegal to use as a weedkiller, but totally fine to use as a compost accelerator.  I prefer to compost my horsetails in situ before they're dead.  Ammonium sulphamate will naturally break down in to ammonium sulphate (a fertiliser) in about 2 months in the ground, after which time you can plant the area.  For my money it has far less serious question marks around it that glyphosate does.

[Galette]

Many thanks to BarriedaleNick, Hippydave, Squeezyjohn and Nodig for taking the time to respond, this is all very useful information.  I have now bought a bag of Ammonium sulphamate to treat these nuisance plants.  The instructions for use as a compost accelerator is 200g per litre of water.  Would that be right for weedkilling Squeezyjohn? I plan to add a small amount of washing up liquid.  As the area to be treated has yet to be developed (it will be for ornamentals) I will remove any useful plants and spray the whole area, leaving the resulting dead plants in situ for a few months so I can treat any regrowth.

[earlypea]

I can see you're happy already, but I'm just going to add to this as it's come up in case anyone's googling.

My allotment used to be totally infested and obviously I can't do the above if I want to grow vegetables.  There's very little about what to do in that case online or there wasn't when I was desperately seeking a solution.

I think two things are very important.

It's seasonal

Deal with it according to the season:  If you keep digging out the roots when it is most active; from late March/April-ish to late July/early August (depending on the weather)  it definitely encourages more growth (I believe the roots branch).  Honestly, I dug one bed out fully 3 times in one growing season when I first had the plot which was disastrous.  And, whenever I used to dig to plant potatoes in March/April they were my worst nightmare mares tail beds.

Dig it out if you must (.....and sometimes that really is the only thing you can do) outside of it's growing season in autumn or winter.  Then only keep picking the tops off as it appears and I mean gently cutting the top growth, not jiggling the roots with a cultivating hoe - any disturbance and it sprouts more shoots.  I do literally go round the plot snipping the mares tail with my scissors in peak season.

The second thing is RAISE the LEVEL of the SOIL

After the above, raised beds totally fox it's growth.  The bed I dug out 3 times in one season I then added nearly a foot of topsoil to and it is virtually gone - I get the occasional tuft (scissors!)  Other beds I have managed to raise a few inches and that's also successful, though not as good as a foot.

I did have a very tall heap of soil/weeds at the back of my plot where the person before me had over decades dug up weeds and tufts of grass and plonked them.  It was at least a metre high and not a single bit of mares tail in it, which is what got me thinking....

It hardly bothers me at all now after 4 years of this approach.  The first three years of digging it out wherever I saw it drove me insane and made it worse.  Other dig-it-out plots are also testimony to that.

It still grows in my paths, which obviously haven't been raised, but as it does very much prefer cultivated, well-composted soil it's fairly minimal on those.

Wish I had photos, but it's never something you think to do at the time and it's too late now (Thank God).  I actually didn't realise I had almost none until a new plot-holder stopped to ask me why I didn't have any.  I looked around and it was true!

Hope this helps someone!