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Crushed Drywall In The Garden??

Marshfield, MA

I buy Gypsum for the garden and I'm not sure it has loosened my soil but was hoping someone could tell me if free old drywall wouldn't do the same thing.
Is there a binding ingredient in the drywall or paper that would make it unsuitable??

I sure not convinced 100's of pounds of Gypsum over the years has changed anything at all. Certainly nothing note worthy.

Magnolia, TX(Zone 8b)

Heard of folks using drywall, but it is actually a really fine powder type material when it breaks down. Never had gypsum do any good either, you just end up planting in gypsum. decide how you want your soil to behave, and replace the organic material it is missing. clay needs fibers in varying amounts of breakdown, the clay is really fine granules that are finer grained than sand. Sand on the other hand can cut the plants because it is such large particles, again stripped of organic matter. Some things just need time to adjust.

Anne Arundel,, MD(Zone 7b)

There's a link to a post about drywall in an older thread

Marshfield, MA

Point taken sally and question answered. I guess I will stick with the pellitized gypsum when I can get it and powdered when forced.

Frankly I have never seen any evidence it does anything even though I do use it. I use what I figure to be "sharp" sand as well. I just buy it as playground sand and I hope that's enough. Fact is you gotta go a little deeper and build up a little higher if you want results. poor drainage can be a tough nut to crack.

We gotta plant the ground we have...

Anne Arundel,, MD(Zone 7b)

Yeah. Drainage generally isn't my problem, on my sandy based coastal plain soil. I haven't read much about soil since Soil 101 way too many years ago. What I have read asserts that adding organic matter to soil always makes a big improvement in structure (assuming you aren't starting with swamp muck or virgin prairie soil)

Zionsville IN, United States

I am curious as to the reason for the use of gypsum, is it possibly relative the the name (Rotted Roots)

Magnolia, TX(Zone 8b)

In gumbo clay earth stripped of humus, the 'gumbo clay' when watered is very soft, when overwatered sticks like gorilla glue to everything it touches, (even to the point of causing your tires to misalign), then when it dries out on top you get horrendous deep cracks that are tough as fired ceramic earth, chuckle. Gypsum is supposed to help this condition by breaking up the packing tendency of the earth, thereby allowing you to have viable planting medium. Your best recourse, most healthy solution for planting is compost, mulch, replenishing the organic material stripped from the earth. I have never seen it provide a lone solution that had any lasting benefits. If you want to change the earth you plant in, it takes more than a simple quik fix. That is why gypsum is suggested as an aid in planting in certain soils. Nuff said.

Marshfield, MA

Adding Gypsum is anything but a cure all and I question if it has ever improved drainage in my poor areas. We don't have Gumbo clay here but I am dealing with a hardpack left from construction years ago.

Amending the soil for most plants is easy and just means you have to get some good stuff in there. That doesn't work as well with trees and larger shrubs. Put all the good stuff you want in the hole and you still end up with a bowl that holds too much water. I already go deeper and wider than I should with the shovel for trees and shrubs so if beating the bottom of the hole with a pick axe and adding gypsum helps it's a cheap partial solution.

I find my drainage actually improves by adding a lot of very strong seaweed and Manure teas. Even if it is an anaerobic sludge a little time and even hard pack appreciates it..

This hole has been draining an hour.. I'm just glad locations this bad are very rare. I think it's from when the gas line went in.

Thumbnail by RottedRoots
Charlotte, NC(Zone 7b)

We started an area in our front yard to be a "rain garden" - the soil is bright red clay. The area hubby dug drains so poorly, it is now a "frog pond". The rain from the front part of our roof pours into this area.

I've decided I like the frog pond idea much better. I love the baby frogs and the calls the parents make at night. I'll be shopping for plants that like wet feet for next year.

North Ridgeville, OH(Zone 5b)

Louisiana Irises love wet clay.

Magnolia, TX(Zone 8b)

Understand your misery Rot, you guys also have a great deal of rock very close to the surface, adds to the drainage woes. At this place there is a great deal of iron ore clay type surface, interspersed with silt sand that appears to have no bottom, my greatest success with sticking trees in ground is to dig an inverted 10 gal hat, with the pick axe and soak method. Twice as deep as necessary for the donut hole, then the donut is dug only half as deep. Cant draw diagrams here, and it is 105 degrees outside, I dont have any holes in progress. the donut hole bottom starts with straight hydromulch at least 18" deep, then a few small stones-as if planting a pot- then my dirts and mulches mixed, the outer donut ring is also filled with mulch an dirt mix, and a trench left to soak during drought times which can be trenched to drain during monsoons, chuckl. I tried gypsum and decided I had better choices to work with- you apparently don't. At least YOU can utilize the gypsum.


Wow!!! We are soooo lucky here in Anchorage. It has rained everyday for 28 days now but the Delphiniums were 8 feet tall and the sunflowers 6 feet. The lilies are just now blooming. We have something blooming from May till freeze up. We have access to all the admendments we need to build our soil up the way we want and at a cost we can afford. I remember trying to dig a cesspool near Hobbs NM. I believe they called it cleachy or something like that. Horrable stuff.

Magnolia, TX(Zone 8b)

Caliche clay_ Kuh leech ee. chalk

Marshfield, MA

I think there are bright spots to living just about anywhere and by the same token everywhere has it's nightmares as well.

I'm not sure whats worse.. No rain in the last 28 days or rain every day for the same period. Hey Chucki. What sort of amendments do you come by for nothing other than moose droppings. JK. I think Anchorage is a great city. I'm just sorry I didn't have my fishing rod. Can't believe the salmom they were catching pretty much downtown! Very cool.

Hey Kit I couldn't figure out how exactly you dug your holes but it sounds like pretty much the same way I do. The root ball sit on a pedistal of pretty much undisturbed soil and the surounding area backed filled? Does Calichi really translate into chalk?? Sounds more like carving than digging if it is.

Have fun.

Magnolia, TX(Zone 8b)

Caliche is white rock, lime base I believe, NM has no rain, so it sets to concrete, when disturbed by travel turns to soft dust and coats everything, I know, lived in Loco Hills, for awhile, chuckl, left a memory when dad was a muttering abt useless almost got it RR, but mine are reverse to yours, opposite issues here.

Everett, WA(Zone 8a)

I also have poor drainage and at first tried digging holes and amending them. That made bathtubs filled with mud.

I find that I need to find a "downhill spot" or slope that I want excess water to run to. Then I cut trenches upslope to where I want plants to grow. If I dig down where the plants are to go, I have to cut the trenches deeper, so they always slope downhill.

You can back-fill with gravel and filter cloth or lay down pierced pipes. For tiny trenches, I have just left them as open shallow slits for now.

There's a practical limit imposed by how low your "low spot" is. It doesn't help to cut a trench deeper than its destination! Neighbors tend not to appreciate receiving your runoff.

(Although I did drain one problem bed into a hole, as a temporary expedient. In any but the heaviest rain, the bed drains and the hole doesn't overflow. Then, the hoole drains or evaporates for as long as it takes.)

I've read that, if you have a long slope ABOVE you, with some permeability, you may have to cut a trench that intercepts water running down that slope (and through the soil under the slope) before it reachs your beds.

As someone suggested above: building raised beds UP can be easier than digging DOWN all the length and width orf your land. The Army Corps of Engineers, we aren't. And, over the years, as time and energy permit, you can always make your rasied beds more productive by adding trenches below them, to d5rain their fondations and aerate a deeper root zone.


Kalispell, MT(Zone 4b)

Clay is best dealt with by as Rick says to used raised beds, also the shape of clay microscopically is flat shaved pieces (glaciation) and run down the large rivers that made the South. These flat pieces are chemically reactive with acid, rounding the flat pieces so acidic fertilizer is the quick solution (Sulfur based inorganic). But the acidity of compost Carbonic acids will do the same thing and it attracts vermiculture to eat and burrow through the clay and provide drainage. Both with acidic rounding of the clay and tunells worms and bugs create, from deep in the soil where they live, to feast on the Nitrogen and Carbon of compost.

Everett, WA(Zone 8a)

I just noticed that the OP was about crushed drywall. Big bags of gypsum (pure Ca-S04) are pretty cheap, and I don't know what other junk they put into drywall to make it fire-resistant and code-compliant.

One source that I read said that the gypsum is effective because of the Calcium ions in it. They are doubly-positive (Ca++)

I speculate (or vaguely remember an illustration from decades ago) that clay (or some common kinds of clay?) tends to have more negative charges on its surface than positive.

Why the DOUBLY-charged Ca++ ion should encourage clumping of microscopic clay particles into "crumbs" , when nromal ground water encourages it to clump into paste when wet and then huge solid hard blocks when dry, I have not yet been able to speculate.

Maybe the size of a hydrated Ca++ ion vs water (H3O+ and OH-) and slats like sodium (Na+)?

As this is the "soil" forum, perhaps a soil scientist would enlighten us! (Or maybe the use of gypsum to help loosen clay is another gardening myth.)

BTW - I wnated to agree with and spread around something someone (Soferdig?) recently poined out. For improving drainage and aeration in outdoor soil, river and and beach sand are not as good as mason's sand (crushed granite?) Crushed rock has a more irregular shape, (less spherical), which helps prevent compaction. Gardeners tend to call that "sharp" sand, perhaps referring to "sharp drainage" whcih i think just meanws "very fast dranage".

I think that river and beach sand (and playbox sand, and any sand I find near bags of concrete at Home Depot) are all much finer-grained than crushed rock usually is. Certainly most bags-of-sand I've seen have mostly very fine grains, even if labelled "med-coarse".

Maybe a concrete yard (or wherever masons shop) would have crushed rock (or fine gravel) screened to be LARGER THAN 1-2 mm, rather than FINER than 1 mm.

I bought a cubic yard from a local "compost-mulch-and-topsoil" place, and really liked how coarse it was.

And I "knew" that was the right kind of sand when the really GOOD gardener down the street saw my pile and ran over to run her fingers through it, ohhh-ing and ahhh-ing!


Kalispell, MT(Zone 4b)

Maybe she was just looking at you Corey when she OOOOOOOhhhhed. Have you asked her for a date yet? LOL

Everett, WA(Zone 8a)

No way! She's "Atilla The Gardener"!

She was looking down at one plant, once, shook her head, and explained her policy that if they didn't thrive, and right away, she'd yank 'em out and shove 'em in somewhere else.

If they didn't thive promptly and look great there: CHOP! Gone, dead, kaput, ba-da-bing, ba-da-boom.

OK, that's one reason she has a beatiful garden. The plants are all AFRAID to stagnate or wilt.

But if that's how she treats plants she's paid for and nurtured,
what would she do to a boyfriend who didn't measure up promptly and reliably?

Rent a chipper?

I just don't want to know (shudder).


Kalispell, MT(Zone 4b)

Sounds a little S&Mish. Maybe it could be fun????? I used to date all of those girls when I was young. Learned my lesson.

Anne Arundel,, MD(Zone 7b)

I am chuckling but can't add much to the current train of conversation.
: ^)
I wanted to mention that last year I bought a product called MirA Cal, a concentrated treatment to substitute for lime. One bag of MiraCal was about the same cost as the many cheap bags of lime it takes to change pH around here. And also gives a good shot of Calcium. I had strawberries and asparagus really do well last year after the MiraCal. It's got me thinking I've been dealing with a calcium deficiency in my sandy loam. I wonder if the Miracal was a smart new way to market gypsum.

Kalispell, MT(Zone 4b)

It is interesting how each area is different with chemicals. We are overwhelmed with Ca+ here. Lime runs out of all of our water and collects on every surface. I have always wondered why Ca+ supplements are used here. And when I lived in Michigan we had to add it by the tons to every field. We always used Dolomite Lime to make it last longer.

Houston Heights, TX(Zone 9a)

It was my understanding that what gypsum does to help clay soil is a chemical reaction definitely, not a physical one. I tried some of the builders gypsum on a new flower bed I was establishing in an area that was mostly clay. I think it worked well to make the soil friable but it also raised the pH of the soil in that bed. I had to amend it back to neutral. I dissolved/suspended the drywall in water and used the liquid to pour onto the soil.

I used raised beds for my veggie garden in an area that was quite gummy even after tilling in bags and bags of humus. I put in a French drain to serve the veggie garden area before building the raised beds there. The drain does not run under any of the beds. I ve been getting good results with my veggies. I used a mix of my own compost, commercial potting soil, crushed stone, and green manure crops turned under.

I had a neighbor who worked at a cement factory where the trucks delivered the different sizes of rock used in the various concrete mixes. The rock was carried by conveyor belt to the mixing area. The small particles of rock would fall off the conveyor belt as the large rock was carried along, piling up under the belt which was a nuisance to them. They called this "crumbles" and gave it away free to anyone who would haul it away. It is quite uniform in size and is particles of what they call "hard rock". It looks like what they sell at the rock store as crushed rock, about 1mm in size. I use it as a cheap substitute for sharp sand or perlite to increase drainage. It does not break down. I also use it in planters to aerate the soil. That neighbor moved away so I no longer have access to this but I was able to get 6 4X4 beds built and filled with soil mix before I lost access.

I would be afraid to use builders gypsum (drywall) to grow food for the same reasons as the above posters. We have black gumbo type clay here.

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