Crazy idea for a shade structure made from sod

I had a crazy idea that I'd like to try.  I'd also like to avoid wasting time and effort on it if it's destined for failure.

I'm working on a community garden where we may cut out a bunch of sod.  We're coming up with options to use the sod and one would be to make a berm-like shade structure.  Like a sun trap but with the protected space facing north.

The idea is to take the sod (let's say 2" thick) and lay it down in a pattern on the ground to make a shade scoop.  Perhaps protecting an area 8' E/W by 6' N/S.  The walls of the berm would be at least 3' wide at the base.  Then each layer would be added and deliberately sized to be a little narrower than the layer below (1/4" underlap all around).  So for every foot of height the wall would barter in 3".  

I'm picturing a curved wall that is about 7' tall when it's done.  3 to 4' thick at the base and 1.5 to 2.5' thick at the top.  One advantage to insetting each layer is that a bit of the grass would be exposed and would quickly grow to knit the structure together.  Seeds, cuttings and transplants could be sandwiched between the layers as well.

A bench could be built into it on the north side to sit on.  A pergola style roof could just lay across it for more shade.  If we have enough sod we could make a second scoop that faces south for a microclimate or basking location for colder days.

Thoughts?  Experiences?

Will the sod be hand cut or machine cut?

Everytime I've tried to work with hand-cut sod  (not even close to your Sod Ziggurat!) I've been disappointed.  The layers aren't even, it tears in weak spots and so it doesn't stack well and then it settles in a very lumpy fashion.

So although noisy, a rented sod cutter might be the thing.

Yes, we are planning to rent a sod cutter and the site is pretty flat so I think the "building blocks" should be of uniform thickness and width.  Length would be somewhat under our control.

Hi Mike

Shade is nice! And sod making fairly thick walls should cast "hard" shade. Ie. the side away from the sun will not be overly warmed during the day; a warm surface radiates that heat, even if it protects you from direct sun, so not all shade is equal.

But I think of a few things:
1) What happens if/when it totally dries out (if that can happen)?
2) How much and how hard driven will be rain events? And what happens?
3) I"m not sure I understand the layout exactly, but I _think_ you mean to construct shade walls, but no roof (of sod). In that case, do you get value during summer when the sun is high?

Idea:
1) Instead of insetting equally on both sides, maybe just one side, with the vertical wall on the shade side. This would give you a degree or so (angle) more sun protection.
2) Sheath the sides with something impermeable in areas where drying out becomes a problem. There would likely need to be a small ventilation space under the sheathing on the sun sides to avoid baking the structure.

Just hip shots. Sounds like maybe a good try.


Cheers,
Rufus

Rufus Laggren wrote:Hi Mike



Idea:
1) Instead of insetting equally on both sides, maybe just one side, with the vertical wall on the shade side. This would give you a degree or so (angle) more sun...


Cheers,
Rufus

That was my thought as well.  I would make the shade side vertical.


I think it's a great idea Mike.

Thanks team!  I was only thinking of keeping the two sides evenly sloped so that the "structure" has the best chance of staying vertical.  If I started at 4' wide and had my intended 1/4" of inset for every 2" layer of sod, by the time it got 7' high it would still be 2'3" wide at the top.  Vertical enough to keep misfits from climbing.  

I'm at 45 degrees latitude so the sun is fairly overhead in summer.  I was thinking of bridging across the sides with logs as a pergola style shade.  

Yes Rufus, when I lived in Utah I appreciated the clear difference between "tree shade" and "rock shade".  I think that was due to the opacity of the rock vs the tree but the thermal mass of the rocks were huge once I was up close to them.  I'm intending this to be a cold pocket where the bench and surroundings would be around 60 degrees on a sunny day with minimal sunlight hitting you through the logs above.  

I might even angle the opening a bit to the NE so that the hot afternoon sun doesn't get into it.  Hmm, or maybe have the west wall a bit longer.

To answer your questions Rufus,

1)  We get decent rain here but the sunny side will probably be a bit dry looking.  Good place for some sage or other dry herbs...
2)  Hard driven rain should be welcome to irrigate the sides of the walls better.  No roof (except for logs across it) so no worries.  If it's raining, people at the community garden will probably just go home or hide in their cars.
3)  I think I hit this one above already

Good idea with the vertical wall on the inside.  I think I'll start with the angled sides and then we can always shave it to vertical once the roots are established.

I'm also thinking I could sheath the sunny side with rocks or urbanite to create a warm microclimate on that side.  It would be a cool demonstration item to have hot on one side with a peach tree and cool on the other with relaxing gardeners

Rocks on the sunny side sounds like a great idea. Win, win, win.

Hope it piles on well!


Cheers,
Rufus