Gypsum for clay soil
Chris J Dixon
lawn for 40 years, I am left with some pretty solid clay soil.
Gypsum is recommended as a soil improver, but appears to be sold
in garden centres as a proprietary product costing nearly �5 for
2.5 kg.
http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
On the other hand, I can pick up a 25 kg bag of multi-finish
plaster for under �5, and AFAIK this is essentially the same
material.
Any reasons not to go with plaster?
Chris
--
Chris J Dixon Nottingham UK
ch...@cdixon.me.uk
Have dancing shoes, will ceilidh.
Tim Watts
> Having just extended a flower bed to incorporate what has been
> lawn for 40 years, I am left with some pretty solid clay soil.
>
> Gypsum is recommended as a soil improver, but appears to be sold
> in garden centres as a proprietary product costing nearly £5 for
> 2.5 kg.
>
> http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
>
> On the other hand, I can pick up a 25 kg bag of multi-finish
> plaster for under £5, and AFAIK this is essentially the same
> material.
>
> Any reasons not to go with plaster?
>
> Chris
No reason whatsoever.
Even better, if you can find a source of lumpy out of date plaster for
free (try asking around).
--
Tim Watts
Hung parliament? Rather have a hanged parliament.
NT
> Having just extended a flower bed to incorporate what has been
> lawn for 40 years, I am left with some pretty solid clay soil.
>
> Gypsum is recommended as a soil improver, but appears to be sold
> in garden centres as a proprietary product costing nearly 5 for
> 2.5 kg.
>
>
> On the other hand, I can pick up a 25 kg bag of multi-finish
> plaster for under 5, and AFAIK this is essentially the same
> material.
>
> Any reasons not to go with plaster?
>
> Chris
Assorted rottable garbage also improves soils, so if you dig it up to
add gypsum, you could add rubbish under the surface too. Unused
plaster will bind the soil, used lumps wont.
NT
Ragnar
"Chris J Dixon" <ch...@cdixon.me.uk> wrote in message
news:009p061f4aaf3f8ku...@4ax.com...
> Having just extended a flower bed to incorporate what has been
> lawn for 40 years, I am left with some pretty solid clay soil.
>
> Gypsum is recommended as a soil improver, but appears to be sold
> in garden centres as a proprietary product costing nearly £5 for
> 2.5 kg.
>
> http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
>
> On the other hand, I can pick up a 25 kg bag of multi-finish
> plaster for under £5, and AFAIK this is essentially the same
> material.
>
> Any reasons not to go with plaster?
>
> Chris
I don't really know the answer to your question, but I would warn you not to
use gypsum if you want lime-hating plants such as heathers, rhododendrons
etc
R.
Andy Dingley
> Unused plaster will bind the soil, used lumps wont.
Run it through a cement mixer and a couple of rocks as a ball mill. So
long as you crunch it down enough to go through a sieve, it's fine.
Even just soaking it in an excess of water would be enough (this is
plaster, not cement).
I wouldn't add "rottable garbage" to soil either, it's much better to
rot this down separately. Otherwise you'll be short of nitrogen and
lawns in particular would suffer badly.
Andrew Gabriel
Tim Watts <t...@dionic.net> writes:
> On 07/06/10 08:57, Chris J Dixon wrote:
>> Having just extended a flower bed to incorporate what has been
>> lawn for 40 years, I am left with some pretty solid clay soil.
>>
>> Gypsum is recommended as a soil improver, but appears to be sold
>> in garden centres as a proprietary product costing nearly £5 for
>> 2.5 kg.
>>
>> http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
>>
>> On the other hand, I can pick up a 25 kg bag of multi-finish
>> plaster for under £5, and AFAIK this is essentially the same
>> material.
>>
>> Any reasons not to go with plaster?
>
>
> Even better, if you can find a source of lumpy out of date plaster for
> free (try asking around).
Yes - where about in the country are you?
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
The Natural Philosopher
> Having just extended a flower bed to incorporate what has been
> lawn for 40 years, I am left with some pretty solid clay soil.
>
> Gypsum is recommended as a soil improver, but appears to be sold
> in garden centres as a proprietary product costing nearly £5 for
> 2.5 kg.
Hmm. I know it is, but I am scptical.
Our clay overlies enough chalk, and though it helps, it does make the
soil excessively alkaline.
We have found copius additions of orgamic material - peats, topsoils and
manures - and sand, to be a better bet.
Its back breaking work as well. Hire a rotovator or small digger to
break it up and mix it in.
>
> http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
>
> On the other hand, I can pick up a 25 kg bag of multi-finish
> plaster for under £5, and AFAIK this is essentially the same
> material.
>
> Any reasons not to go with plaster?
>
As previous poster says, none really, except it sets hard and can make a
mess of drainage in a particular area. The same is probably true of pure
gypsum.
I've got areas of lawn that I simply left cement and plaster tailings
under and heaps of builders sand, They don't fare well.
The easy way of of making flower gardens in clay, is mulch. That will
decompose into decent topsoil, and you can pull annual weeds out of it.
Wood or coca shell. Or peaty compost.
Or if its for vegetables, cheat: We made raised beds and filled them
with gravel sand and topsoil. After breaking up the underlying clay pan
just a little.
> Chris
Chris J Dixon
See sig. Ironically, in a village whose major industry is
plasterboard ;-)
Tim Watts
> Andrew Gabriel wrote:
>
>> In article<hui97a$dku$2...@news.eternal-september.org>,
>> Tim Watts<t...@dionic.net> writes:
>
>>>
>>> Even better, if you can find a source of lumpy out of date plaster for
>>> free (try asking around).
>>
>> Yes - where about in the country are you?
>
> See sig. Ironically, in a village whose major industry is
> plasterboard ;-)
>
> Chris
I've got one of the gypsum mines and processing facilities round the
corner from me too. Ironically the dump bang over the road is unable to
accept plasterboard for recycling(!)
Jim K
> On 07/06/10 12:12, Chris J Dixon wrote:
>
> > Andrew Gabriel wrote:
>
> >> Tim Watts<t...@dionic.net> writes:
>
> >>> Even better, if you can find a source of lumpy out of date plaster for
> >>> free (try asking around).
>
> >> Yes - where about in the country are you?
>
> > See sig. Ironically, in a village whose major industry is
> > plasterboard ;-)
>
> > Chris
>
> I've got one of the gypsum mines and processing facilities round the
> corner from me too. Ironically the dump bang over the road is unable to
> accept plasterboard for recycling(!)
could that be addressed by the fabled "joined up thinking" we are all
looking forward to?
(IOW can you recycle old pb into new pb?)
Jim K
Tim Watts
I must admit - I don't know if British Gypsum do recycling at the
Mountfield/Robertsbridge plant. Though if they can take crap out the
ground and turn it into plaster (they do all that here) I would have
thought they would have added a preprocessing feed for doing whatever
you need to old PB and sticking the result of it in with the raw
materials from the mine.
Chris J Dixon
>
>"Chris J Dixon" <ch...@cdixon.me.uk> wrote in message
>news:009p061f4aaf3f8ku...@4ax.com...
>> Having just extended a flower bed to incorporate what has been
>> lawn for 40 years, I am left with some pretty solid clay soil.
>>
>> Gypsum is recommended as a soil improver, but appears to be sold
>> in garden centres as a proprietary product costing nearly �5 for
>> 2.5 kg.
>>
>> http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
>>
>> On the other hand, I can pick up a 25 kg bag of multi-finish
>> plaster for under �5, and AFAIK this is essentially the same
>> material.
>>
>> Any reasons not to go with plaster?
>I don't really know the answer to your question, but I would warn you not to
>use gypsum if you want lime-hating plants such as heathers, rhododendrons
>etc
>
Other sources seem to be of the opinion that one of the benefits
of using gypsum is that it is essentially neutral, and will not
alter pH.
spamlet
Interesting how gypsum comes out of nasty thick clay pits, yet we put it
back in as a clay improver?
S
The Natural Philosopher
If that's true, its news to me..
pretty sure that vinegar dripped on plasterboard fizzes..
> Chris
The Natural Philosopher
mildly alkaline. giving a typical PH of about 7.4
If its the raw plaster of paris, its even more alkaline at a ph of 11+
nm...@cam.ac.uk
This is a TBE and a FQM (Totally Baffling Effect and Frequently Quoted
Misunderstanding). You are chemically correct, but biochemically
incorrect.
It isn't helped by the fact that the terms "acid soil" and "alkaline
soil" are so misleading - which is the TBE. The reasons that those
plants dislike lime has nothing to do with the acidity, but the fact
that they have difficulty absorbing iron, and calcium interferes
with one common form of plant's lime absorption. Sorry, I don't
know the details. Magnesium doesn't have the same effect, for
arcane chemical reasons, that I don't understand, either.
Regards,
Nick Maclaren.
The Natural Philosopher
Now it makes a little more sense..
> Regards,
> Nick Maclaren.
NT
So they say, but I've not seen this happen in practice. If you added
wood shavings or plenty of paper I daresay it would.
NT
NT
> Having just extended a flower bed to incorporate what has been
> lawn for 40 years, I am left with some pretty solid clay soil.
>
> Gypsum is recommended as a soil improver, but appears to be sold
> in garden centres as a proprietary product costing nearly 5 for
> 2.5 kg.
>
>
> On the other hand, I can pick up a 25 kg bag of multi-finish
> plaster for under 5, and AFAIK this is essentially the same
> material.
>
> Any reasons not to go with plaster?
>
> Chris
Building plaster has other stuff in it besides gypsum, anyone know
what those additives are?
NT
Bob Hobden
"Chris J Dixon" wrote
> Having just extended a flower bed to incorporate what has been
> lawn for 40 years, I am left with some pretty solid clay soil.
>
> Gypsum is recommended as a soil improver, but appears to be sold
> in garden centres as a proprietary product costing nearly £5 for
> 2.5 kg.
>
> http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321.html
>
> On the other hand, I can pick up a 25 kg bag of multi-finish
> plaster for under £5, and AFAIK this is essentially the same
> material.
>
> Any reasons not to go with plaster?
>
Chris, if you can find a Farmers Shop (not a Farm Shop) they may well sell
Agricultural Gypsum in 25kg bags, which is what I bought. Mine was old
stock, a bit lumpy, and I paid £5. each.
--
Regards
Bob Hobden
W.of London. UK
The Natural Philosopher
But in general, yes. 3 years and then apply compost. You can hurry it
along, but why bother?
Gardening is a long term investment.
> NT
Bob Hobden
"Tim Watts" wrote
>
> I must admit - I don't know if British Gypsum do recycling at the
> Mountfield/Robertsbridge plant. Though if they can take crap out the
> ground and turn it into plaster (they do all that here) I would have
> thought they would have added a preprocessing feed for doing whatever you
> need to old PB and sticking the result of it in with the raw materials
> from the mine.
>
British Gypsum make cat litter too, Nature Cat Gold, so that is probably
also gypsum and it's in granules too. Should be available at any good pet
place or could be ordered, but check the price first. Worth ringing BG first
to find out if it is pure gypsum.
The Natural Philosopher
filler mainly. Mica and so on. that's yer carlite bonding anyway.
The finishing plaster is almost pure gypsum IIRC.
>
> NT
stuart noble
AIUI gypsum is the raw mineral, which doesn't set when mixed with water.
It has to be hydrated to make plaster.
The Natural Philosopher
T'other way about. Gypsum is the hydrated stuff, which has to be
reducedd (de hydrated) to make plaster..then addition of water
rehydrates it, and it crystallises into solid chunks.
NT
wrote:
Vegetable garbage does wonders for the worm population, which produce
a fair bit of good poop. If there is such a thing.
NT
The Natural Philosopher
Interesting. We just compost ours.
takes a fair time to rot down, and the rats get a fair bit.
> NT
The Natural Philosopher
> Belgium and northern France; hence the name Plaster of Paris. However,
> the modern desulphurisation of flue gases from coal-fired power
> stations, using a slurry of hydrated lime and ending up with a slurry
> of (mostly) gypsum, has resulted in lots of cheap gypsum as a waste
> by-product. This means that gypsum mining is no longer commercially
> viable except for specialist application that can carry the cost. The
> conversion of hydrated lime to calcium sulphate (gypsum) during the
> desulphurisation process is not 100% efficient, simply because the
> efficiency of sulphur oxide absorption drops off when there's not much
> lime left in suspension, so it's not cost-effective to keep using the
> lime slurry until it's 100% converted. After filtering and drying, the
> residual lime in the gypsum reacts with carbon dioxide in the air to
> give calcium carbonate (think: lime mortar). Hence most of the gypsum
> currently available will fizz with dilute acid, and has an alkaline
> pH. Pure gypsum doesn't fizz in this way, and naturally has an acid
> pH.
>
> The reason some plants dislike 'lime' has a great deal to do with soil
> acidity. In this context, 'lime' actually means calcium carbonate
> (chalk), rather than quicklime (calcium oxide) or hydrated lime
> (calcium hydroxide), both of which convert fairly quickly in the soil
> to calcium carbonate by reacting with carbon dioxide in the air.
> 'Limey' soils, i.e. chalky soils, typically have pH values of around 8
> to 8.5. So-called lime-hating plants such as many of the ericaceae
> have a greater requirement for iron (and possibly manganese), than
> other plants. The solubility of iron and manganese in the soil
> decreases significantly as the soil pH increases from say pH 6 to pH
> 8.5 (neutral is pH 7), a typical range of soil values. At the high pH,
> there just isn't enough iron and manganese available in the soil to be
> taken up by the plants to satisfy their needs, and yellowing of the
> leaves (chlorosis) is the result. It has nothing to do with the
> presence of calcium in the soil per se. Pure gypsum (not the modern
> stuff from desulphurisation) used to be recommended as an additive to
> heavy soils to open them up, where it was wanted to grow
> rhododendrons, in place of 'lime' which has a similar effect on the
> soil but is alkaline.
>
Thank you!
well written and increases understanding. Can't ask for more!
now to buy some of that manganese and iron feed for the 'ericaceous' tubs.
Andy Dingley
> >This is a TBE and a FQM (Totally Baffling Effect and Frequently Quoted
> >Misunderstanding). You are chemically correct, but biochemically
> >incorrect.
>
> >It isn't helped by the fact that the terms "acid soil" and "alkaline
> >soil" are so misleading - which is the TBE. The reasons that those
> >plants dislike lime has nothing to do with the acidity, but the fact
> >that they have difficulty absorbing iron, and calcium interferes
> >with one common form of plant's lime absorption. Sorry, I don't
> >know the details. Magnesium doesn't have the same effect, for
> >arcane chemical reasons, that I don't understand, either.
>
> >Regards,
> >Nick Maclaren.
No quote chopping, so that it hits the archive fully.
So what's the stuff from the graden centres? Pure gypsum rather than
FGDS, so as to avoid the alkalinity change?
Ian B
No, that's made from bentonite clay, which is the most absorbent, clumpy
dirt the Earth can offer.
Ian
stuart noble
Ah, right! But gypsum, as in agricultural gypsum, presumably doesn't set
then? Not that it makes much difference when it's mixed with soil.
I'd think about vermiculite as a conditioner. Okay, you have to break
the clay up to incorporate it (which probably does more to improve it
than any additives), but it aerates the soil permanently and doesn't
break down into anything else. Just don't buy the agricultural grade,
which is rather over-priced.
The Natural Philosopher
> On Mon, 7 Jun 2010 15:59:26 -0700 (PDT), Andy Dingley
> <din...@codesmiths.com> wrote:
>
>
>> So what's the stuff from the graden centres? Pure gypsum rather than
>> FGDS, so as to avoid the alkalinity change?
>>
> latter. A simple pH test would tell you.
>
there would be no reason to supply anything other than the dihydrate for
any purpose other than actually making plaster.
Its costlier and has shorter shelf life.
Andrew Gabriel
stuart noble <stuart...@ntlworld.com> writes:
>
> Ah, right! But gypsum, as in agricultural gypsum, presumably doesn't set
> then? Not that it makes much difference when it's mixed with soil.
Building gypsum sets initially when you dump it outside, but as
it's slightly soluable anyway (which is why damp eventually destroys
plasterwork), it quickly crumbles apart again when kept wet, and
plants have no problems pushing roots through it. Grass seems to
love growing on it.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
Tim Watts
> In article<CNoPn.29680$hP7.6557@hurricane>,
> stuart noble<stuart...@ntlworld.com> writes:
>>
>> Ah, right! But gypsum, as in agricultural gypsum, presumably doesn't set
>> then? Not that it makes much difference when it's mixed with soil.
>
> Building gypsum sets initially when you dump it outside, but as
> it's slightly soluable anyway (which is why damp eventually destroys
> plasterwork), it quickly crumbles apart again when kept wet, and
> plants have no problems pushing roots through it. Grass seems to
> love growing on it.
>
Yes indeed. The bit of my lawn used last year for dumping plaster
washings (from mixing) is fine. In fact the grit from the coal ash
bucket seems to be upsetting it more.
--
Tim Watts
Hung parliament? Rather have a hanged parliament.
Weatherlawyer
> Ragnar wrote:
>
> >"Chris J Dixon" <ch...@cdixon.me.uk> wrote in message
> >news:009p061f4aaf3f8ku...@4ax.com...
> >> Having just extended a flower bed to incorporate what has been
> >> lawn for 40 years, I am left with some pretty solid clay soil.
>
> >> Gypsum is recommended as a soil improver, but appears to be sold
> >> in garden centres as a proprietary product costing nearly 5 for
> >> 2.5 kg.
>
> >>http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321....
>
> >> On the other hand, I can pick up a 25 kg bag of multi-finish
> >> plaster for under 5, and AFAIK this is essentially the same
> >> material.
>
> >> Any reasons not to go with plaster?
> >use gypsum if you want lime-hating plants such as heathers, rhododendrons
> >etc
>
> Other sources seem to be of the opinion that one of the benefits
> of using gypsum is that it is essentially neutral, and will not
> alter pH.
Gypsum is calcium sulphate which is more or less neutral but is
calcium rich which will hurt alpines. Nothing seems to hurt
rosydandelions.
Sand is neutral and acid. Use a mix of sand and gypsum with sawdust or
shedded organic stuff. Grow lupins for a while. Any nitrogen loss will
soon come back.
Sand and clay = loam. I think sand and gypsum = marl.
The Natural Philosopher
> On Mon, 07 Jun 2010 21:06:14 +0100, Chris Hogg <m...@privacy.net> wrote:
>
>> Gypsum is the fully hydrated form (di-hydrate, CaSO4.2H2O). There are
>> several types of plaster, but the common one is the hemi-hydrate
>> (CaSO4.½H2O), made by heating gypsum to around 125°C, when it loses
>> water. On suspending in water, this reverts to the di-hydrate and
>> sets.
>
> Does this mean I can re vitalise old multifinish by heating it to
> 125C?
>
I thought it was a bit hotter than that..
and it will bneed re grinding in a ball mill or similar, but yes, in
principle..
> I've just had to recycle 980kg of plaster materials (at a cost of 65
> quid plus delivery) which I suspect is about 30% of what the builders
> purchased. I've gone right off dot and dabbed plasterboarding as a
> result even given the time saving. Conventional plaster also is easier
> to fix to.
>
> AJH
>
harry
> "Chris J Dixon" <ch...@cdixon.me.uk> wrote in messagenews:009p061f4aaf3f8ku...@4ax.com...
>
>
>
>
>
> > Having just extended a flower bed to incorporate what has been
> > lawn for 40 years, I am left with some pretty solid clay soil.
>
> > Gypsum is recommended as a soil improver, but appears to be sold
> > in garden centres as a proprietary product costing nearly �5 for
> > 2.5 kg.
>
> >http://www.capitalgardens.co.uk/clay-breaker-soil-conditioner-p-6321....
>
> > On the other hand, I can pick up a 25 kg bag of multi-finish
> > plaster for under �5, and AFAIK this is essentially the same
> > material.
>
> > Any reasons not to go with plaster?
>
> > --
> > Chris J Dixon �Nottingham UK
> > ch...@cdixon.me.uk
>
> > Have dancing shoes, will ceilidh.
>
> Interesting how gypsum comes out of nasty thick clay pits, yet we put it
> back in as a clay improver?
>
> S- Hide quoted text -
>
> - Show quoted text -
Most gypsum come from scrubbers fitted to coal burning power
stations. The sulphur dioxide converts limestone to calcium
sulphate. The best permanent clay improver is "sharp" sand. The
difficult bit is mixing it thoroughly with the clay. Even a
rotovator is not very good as it only churns up the top layer. It's
taken me three years to get it mixed with hand digging but the results
are good. Compost is the way to go too.
Get yourself a shredder if you have a big hedge. If you know a
landscape gardener, you get get truck loads of shreddings off them for
free. They compost down very quickly if there's lots of leaf. ie
Summer time is the best.