An interesting way to kill marestail/horsestail

[thexman]

Now here's an interesting piece of serendipity...

Having a manifestation of marestail on a third of my new plot, I set about erradicating it.

I bought - or so I thought - a compost activator (ammonium sulphamate), which simply forces the plant to destroy itself and is the closest thing that you can get to a 100% solution to marestail. It is a bit brutal, though, killing everything around it and remaining active in the soil for about three months before breaking down into fertiliser. As such, it can't be used everywhere.

I began to get bizarre results. I sprayed, the marestail died, but everything else around it remained alive. I tried spraying other weeds, but mostly there was only scorching to the leaves; they survived. I checked the box: it wasn't ammonium sulphamate that I had bought, but rather ammonium sulphate, a fertiliser used on alkaline soils to make them more acidic!

As many of you will know, marestail/horsestail prefers marginal ground where other weeds don't often grow and hates very fertile soil. By applying the fertilser, I had reduced the PH of the soil and the marestail died. It has acted as a selective herbicide. Weird, eh?

I dissolved it in water, at a concentration of 100 grams per litre, which my chemistry friend says is quite a high concentrate, which explains why the marestail had died. Being a fertiliser, it won't do any harm to the soil as such, with the extra salt being broken down by other plants.

However, the question remains: will the marestail come back again or have I simply burned the tops off?

Anybody want to hazard a guess?

I'm on tenterhooks. Sulphate is significantly (x5) cheaper than sulphamate.

[thexman]

[ed dibbles]

Interesting. Please let us know how it works out and whether, as you wonder, that you may have only killed the top growth or dealt with the mares tail once and for all.

I know many of us have looked, often in desperation, for a solution to mares tail.

For my own part I use neat glyphosate and an artists paintbrush.  Over that last couple of years I have managed to eradicate all the bindweed from one plot and am now winning against the same weed on the other.

On that plot there is also a moderately light infestation of mares tail that I am having success against with neat glyphosate. There is a particularly bad spot in the area the broad beans are destined for planting in October.

This area has been treated with normal strength diluted glyphosate, which knocks out all the weeds leaving the weakened thugs bindweed and mares tail.

Over the next couple of months it is out with the neat stuff and the paint brush to hit them as hard a possible.

Even if ultimately there is a  little regrowth to deal with the ground will be a lot clearer than otherwise and easier to spot treat as and when.

A tip if attempting to spot treat among growing plants is to wait until the bindweed and mares tail has grown a bit, perhaps 12 to 18 inches for bind weed and 9 to 12 inches for mares tail. At these heights it is easy to unwind the bindweed from any growing plants laying it on the ground away from anything, likewise the mares tail. Then a good dose painted on as much of the plant you can safely reach. For the mares tail I paint the stem as well as the foliage as that seems to be more effective.

But please do let us know how the ammonium sulphate works. Any weapon in the fight against mares tail is always welcome.

[Tee Gee]

It does not surprise me that you have found a fertiliser rather than a herbicide an effective treatment.

Various individual plots on out site are infested with mares tail and I have looked at the cultivation methods used on the affected plots and generally speaking the plots with mares tail I think are not fertilised well enough.

Over the years I have spent on our site I have had various plots and occasionally I have had mares tail on them which I usually got rid of within a couple of seasons.

I never used herbicides I generally only resorted to hoeing the tops of the plants as it grew,then as the fertility of the soil improved the mares tail disappeared.

I think it is one of those plants that can only survive in very poor quality soil e.g. Very acidic or very alkaline.

Once I get my soil to somewhere between pH 6-7 the mares tail always disappeared.

So in my opinion feeding it might be a better cure than starving it.

I emphasise this is only an opinion, all I know is; I have got rid of it by the aforementioned methods.

[PAULW]

There was an organic/green weedkiller containing ammonium sulphamate, sold I think by growing success that was brilliant at killing mares tail then they changed the recipe because of EU regs and it was never the same again

[thexman]

To go slightly off subject, a friend of mine has completely erradicated bindweed from his plot. He uses glyphosphate, but not in the conventional manner. Instead of the recommended dose, he sprays regularly using one quarter of the dose that is recommended. His logic is that virtually all doses put on packaging are too strong, often killing off the top of the plant, but leaving the roots intact, despite claims of being a systemic weedkiller. By continually spraying the bindweed with this low concentration, the plant takes it in, doesn't die right away, but shifts the glyphosphate deep down into the roots and effectively kills the plant over the space of a week. He doesn't need to respray; it never regrows.

Call me cynical, but instructions on weedkillers often state that you may have to reapply the spray several times, which implies using a lot more product. But by cutting the dose, you effectively choke the plant to death.

To digress, it is like using calgon in washing machines. My washing machine repair man told me to half the dose on the packet and only use it on alternative washes, since the whole point of calgon is to shift limescale. If you use it every time, the calgon will have nothing to shift. In other words, you are wasting money. Ditto, it seems, for many systemic weed killers.

Has anybody else tried this method?

[claybasket]

Hi, having a bad nights sleep  we move house 9 months ago and this is the first summer getting to grip with the garden,we have Japanese  knot weed! I've read the horror's the weed can do,did report it to land lord,
they have a company that spray's or injects it the plant in the Autumn I couldn'twait that long it grows 3inches a day! so i got some glyphosphate in a spray bottle full strength! and got a old knife and slit down near the base of the plant and sprayed into the slit twice a week ,its DEAD!!! :icon_

[alkanet]

there's a recipe for marestail in the Japanese film "Little Forest - Winter Spring" (which is just a collection of recipes, including Worcester sauce)

"they might be the tiny spirits of the green earth, gallantly aiming towards the heavens"

[Vinlander]

I read a while back that growing turnips on the area would kill horsetail - this is not an old wives' tale - it was supposed to be first-hand experience.

Unfortunately I can't remember where I read it - though I'm pretty sure the intention was to get a usable crop of turnips into the bargain - so I assume they would have fertilised the soil first (which might put the horsetail at a disadvantage straight off...).

Cheers.

[galina]

I read a while back that growing turnips on the area would kill horsetail - this is not an old wives' tale - it was supposed to be first-hand experience.

Unfortunately I can't remember where I read it - though I'm pretty sure the intention was to get a usable crop of turnips into the bargain - so I assume they would have fertilised the soil first (which might put the horsetail at a disadvantage straight off...).

Cheers.

I heard it from Mr Yeoman/Village Guild and the turnips were supposed to get the better of couch grass, if I remember right.   

[lezelle]

Hi Ya, how interesting. I will be happy to see how you fair with the suphate. My friend used sulphamate and said within 6 weeks all was gone. Haven't seen him recently to see how he got on. Interesting idea about 1/2 dose and I see the company would tell you to use more. I use resolva but only on dire need. The sulphamate is quite expensive I thought. I wonder if it would over the winter months? vey good post Happy gardening

[Vinlander]

I heard it from Mr Yeoman/Village Guild and the turnips were supposed to get the better of couch grass, if I remember right.   

Thanks Galina - sorry to admit that my memory is even more likely to lapse into wishful thinking than my (dubious) powers of logic are...

My Mum suffered from horsetail in her garden and I can tell that memory is clearly of the same vintage - obviously the two memories are totally incompatible (I know the horsetail was still there when she moved out).

Regards from cloud-cuckoo land!