WTH is "Gypsum"

Discuss hardy cacti grown outside all year.
LadyV
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WTH is "Gypsum"

Post by LadyV »

Herein Winslow we have one place to get anything and that is a Wal-Mart that is supposed to be a super Wal-Mart but it's really not, not like what I'm used to as a super Wal-mart. Aaaaanyway, there is a "Home Improvement" store here that carries tree and flowers and such, but your very limited here unless you drive to Flagstaff an hour away. I was reading up on making your own soil for Cacti (is that the proper usage?)I saw nothing what-so-ever of what I needed, but I saw "Gypsum" it was cheap and I bought figuring I would use it at some point....what exactly is this stuff good for. I did a google on it?
peterb
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Post by peterb »

I have never used it as an additive, but I know there are cacti that are adapted to grow in very high gypsum soils, or almost pure gypsum. These gypsophilic cacti are more common in Mexico, although I guess one of the Scleros is a gypsophile (is it Sclerocactus sileri?)

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Peterthecactusguy
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Post by Peterthecactusguy »

PeterB, I would assume that some cacti in Cali grow in gypsum because that is where they mine it. And I saw some Opuntia in Dirty Jobs when he went to mine gypsum.
:)
course those can probably grow on the moon if it was warm enough, and got enough water!
Here's to you, all you insidious creatures of green..er I mean cacti.
LadyV
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Post by LadyV »

So...can I mix it in the soil? Should I mix it in?
iann
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Post by iann »

Gypsum is calcium sulphate. It is a white, or often slighty dirty brown, coloured powder. Sometimes they make it into granules. Where it forms cactus soils it makes a very loose crumbly rock which is both extremely well drained and extremely lacking in nutrients. Harsh stuff! No surprise that the cacti that grow in it tend to be very slow growing.

Some people add it to soil for growing cacti that naturally grow on gypsum. Some people even add it to soil instead of limestone for those species that grow on limestone. What you definitely shouldn't do is use it with plants that don't grow on gypsum or limestone because they will suffer. I would also suggest that you don't use it for those plants that grow on limestone - use limestone (or marble, or oyster shell, or whatever) if you feel the need.

So how many Aztekium, Geohintonia, and Pediocactus sileri do you have? Apparently a number of Turbinicarpus species, Strombocactus disciformis, and several Mammillarias may also be found on gypsum. Some Sclerocactus can be found on gypsum, including "Sclerocactus" (aka Glandulicactus) wrightii, "Sclerocactus" (aka Ancistrocactus) brevihamatus, and Sclerocactus mesa-verdae, but *not* S. sileri. No doubt many other limestone lovers also find their way onto gypsum from time to time.

Lastly, gypsum is widely recommended as a bulk soil amendment for breaking heavy clay soils. I suspect this information is of no use to you.
--ian
LadyV
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Post by LadyV »

Thank you
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Peterthecactusguy
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Post by Peterthecactusguy »

iann wrote:
Lastly, gypsum is widely recommended as a bulk soil amendment for breaking heavy clay soils. I suspect this information is of no use to you.
Ian, from what I understand you have to keep re-applying the Gypsum to the soil if you want to break the caliche. It works by breaking the seal of the caliche thus allowing water to flow through it. it's some sort of chemical reaction, that I didn't really understand. However I have caliche and I can grow lots of plants in it or above it....fine so I don't add anything to the soil!
Here's to you, all you insidious creatures of green..er I mean cacti.
A. Dean Stock
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Post by A. Dean Stock »

The Pediocactus or Sclerocactus species in Utah that I've seen grow in soils with varying amounts of gypsum and in some areas with very little gypsum. S. sileri that I've seen recently on the Paria Plateua are growing in about the same amount of gypsum content as those P. wrightii that grow in clay or gravelly soils . I don't think that any of the Sclerocactus or Pediocactus species in my area actually require much gypsum to be "happy".
Iann, The accepted generic name is Sclerocactus wrightii (not Glandulicactus). "Hunt (2006) adopted a broad circumscription of Sclerocactus that inclued Ancistrocactus, Echinomastus, and Glandulicactus. While molecular data (Porter et al.2000) do not refute a broader circumscription of Sclerocactus, Glandulicactus would have to be excluded to preserve monophyly.(From Pinkava et al. Intermountain Flora.Manuscript.) This is probably more on the subject than might be desired but I recently reviewed some of the manuscript the infomation is from and it was fresh in my mind.
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iann
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Post by iann »

from what I understand you have to keep re-applying the Gypsum to the soil if you want to break the caliche. It works by breaking the seal of the caliche
Caliche isn't clay. It is limestone, effectively solid limestone rock formed by rainwater dissolving and re-depositing limestone particles from an otherwise loose soil. I can't imagine gypsum would do anything to caliche, it certainly won't do anything to limestone rock. Some areas have both clay and caliche, and maybe gypsum could help them, but you'd still need a pickaxe to get through the caliche.

Just to confuse things, some gypsum soils are also known as caliche :roll:
--ian
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Post by iann »

I don't think that any of the Sclerocactus or Pediocactus species in my area actually require much gypsum to be "happy".
The only one I'm aware of that grows almost entirely on gypsum rich soils is Pediocactus sileri. I don't use gypsum on any of these plants, although I don't have P. sileri ;) The same for many other plants that are sometimes found on gypsum or soils with some gypsum, such as Turbinicarpus beguinii, T. lophophoroides, Strombocactus, and Mammillaria albicans.
The accepted generic name is Sclerocactus wrightii (not Glandulicactus).
I usually follow the NCL, or occasionally a more recent reference, and I do always keep the accepted name in my database but in this case I prefer to use Glandulicactus. Partly for the reasons you have described and partly because it just doesn't behave anything like a Sclerocactus. It is so easy that even I can grow it from seed to flowering :shock:
--ian
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GermanStar
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Post by GermanStar »

iann wrote:
from what I understand you have to keep re-applying the Gypsum to the soil if you want to break the caliche. It works by breaking the seal of the caliche
Caliche isn't clay. It is limestone, effectively solid limestone rock formed by rainwater dissolving and re-depositing limestone particles from an otherwise loose soil. I can't imagine gypsum would do anything to caliche, it certainly won't do anything to limestone rock. Some areas have both clay and caliche, and maybe gypsum could help them, but you'd still need a pickaxe to get through the caliche.

Just to confuse things, some gypsum soils are also known as caliche :roll:
Yes, that's it exactly. The idea is that after a few years of gypsum applications, you'll no longer need a pickax to get through the soil -- unless it's riddled with caliche.
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Peterthecactusguy
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Post by Peterthecactusguy »

haha ok, maybe I was confusing clay and caliche. LoL I mean I have some caliche that has some clay with it, so I dunno, maybe people have clay without the caliche.

haha :oops:
Here's to you, all you insidious creatures of green..er I mean cacti.
A. Dean Stock
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Post by A. Dean Stock »

I live only 20 miles away from a population of P. sileri and many of the plants I've seen recently are growing in soil that is not rich in gypsum. I think that people see plants of sileri growing in areas with fair amounts of gypsum in the Moenkopi formation but within that deposit are many areas with no gypsum and P. sileri grows thoughout the full range of soil types. Certainly, the species is tolerant of gypsum soils but does not require high gypsum content to grow well. I've seen several plants transplanted at Pipe Springs, Arizona to make room for a Service Station and they were planted on rather sandy non gypsum soil where they are thriving.
Iann, despite its its ease of culture, S.wrightii cannot be a member of Glandulicactus as DNA data support its inclusion in Sclerocactus and excludes it and all other Sclerocactus from Glandulicactus. Fortunately, it is easy to grow otherwise we could easily see it vanish.
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DaveW
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Re: WTH is "Gypsum"

Post by DaveW »

I have been using a little gypsum and limestone chips for some N. American cacti as a trial, but like most of you I wonder if they just grow on it because they have to, due to lack of competition from more vigorous plants rather than by choice, since I recently found this:-

http://puyallup.wsu.edu/~linda%20chalke ... Gypsum.pdf" onclick="window.open(this.href);return false;

I sometimes wonder if the same applies to adding limestone chips to cactus soils too, since some claim their only function is as a growth retarder to stop the plants becoming bloated and out of character, even though bloated green plants may get you first prize in competitions with present judging standards?

Not sure I entirely go along with everything in the following link though:-

"The fact that some plants have adapted very well to alkaline pH does not mean that they don’t accept – for short to medium periods of time – to grow in much richer soils with a rather acid pH, and they might even apparently enjoy this! The real problem is that these plants will soon show aberrant growths. The alkaline pH induced by limestone is a growth inhibitor for these plants; by lacking this inhibitor plants will grow to their potential, and not to their natural size. This aberrant growth – some plants look like being literally pumped up – contributes not only to the loss of their specific natural aspect, but especially makes them weaker when confronted with biotic and abiotic factors the plants are now unable to overcome. They become literally unrecognisable – lose their compact forms, the specific colours of the epidermis, their exceptional spination becomes weaker, etc."

"It is true that seen as living beings plant’s metabolism does not need – in any form – limestone in the soil, plants having various ways of gathering all the calcium they need from various minerals. However, certain limestone content is highly recommended for calciphyte plants, so that plants don’t have an “unnatural“ aspect. Plants growing naturally in limestone dominated habitats are more or less natural bonsai. Deprived from limestone these plants return to what they “could have been” without it, far from what they really are, at least out in the wild. Sometimes they will show spectacular growth."

http://www.cactiguide.com/pdf_docs/hexalog-engl.pdf" onclick="window.open(this.href);return false;

I suppose what is really needed is a proper scientific trial with control plants, plus some with limestone chips and some with gypsum, plus some with both. But then how do you judge them, as freely growing show winners, or as plants characteristically mimicking their wild cousins? A friend of mine is using gypsum in his compost and says the plants spination has improved, but whether that will be at the expense of slower growth remains to be seen.
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Re: WTH is "Gypsum"

Post by adetheproducer »

This experiment is already in the pipe line, I have about 12 or 13 stobocactus disciformis, once they are ready to re-pot I intend to grown some on a gypsum mix, some on a limestone mix, some in gypsum plus limestone mix and some in gypsum and limestone free mix. I will post the result in the cultivation section when I have them but the seedling are only a few millimeters across so it is a while off yet, maybe the end of the summer if they grow enough.
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