pulpo, Did you need a "box"? You can just make the beds level to your lawn or pile up the soil slightly to make a raised bed. You don't really need a box/walls. Billie

Pulpo,
We have used the SFG method in our raised bed for several years. I don't always go with a SF, but it helps to 'map' out the inches for planting.
I have a couple comments and sort of questions:
1) Are you making 'portable SFG boxes', if so a form created by 2x4"or2x6" would give you the size you want, use screws to hold together so you can also take the frame work apart later. Create the frame work on a solid surface covered in plastic (if you plan to release it later), placing a bottom of tufa 1-2" thick and then going up the sides at least a 1 1/2" thickness to support the size you are mentioning above. You can put drainage holes in but I don't think they are absolutely necessary. Once dry you can remove the sides, and re use the form.

2)If you are making a non portable SFG container but want the tufa sides, create it as Billie suggests right on the ground. You can use the form described above, just make the form in place, knock away the sides when dry and scruff up if you want some texture.
Great idea to create a SFG bed out of tufa. It is so versital.
Happy casting and texturizing,
Dena

Thank you so much for the replies.

I would like the SFG boxes to be elevated to keep them away from my dogs and to make it easier on my back while tending.

There is also the aesthetic appeal of an elevated SFG box that allows for a shade grass (e.g., monkey grass) to be planted beneath it; making it a 2-for-1 lawn & garden. Since I may end up covering both my back and - more importantly - front yard in these boxes, the way it looks will be an issue.

I have yet to figure out exactly how to best elevate it (form a cost and functionality standpoint) but I am considering setting each box upon four rough cedar limb posts that are set in ground with concrete. Another possibility is stacked concrete blocks. The desired height of any option is around 3' tall.

Any ideas on how to best elevate the completed box will really be above and beyond the call of duty.
And if I haven't asked enough of you kind people, any estimate of the final weight of the box described, as well as the approximate cost of materials for one completed box, will also be most appreciated.

Thanks again!

pulpo

Here is a link that might be useful: rough cedar posts

Pulpo,
I recently built 4 raised beds out of 2x12 boards and 4x4 posts in the corners. 3 of them are 4' x 8' to be used for a garden next year and 1 is a 6' octagon for my kid's sandbox. I used cheap fir, an oil based primer and standard exterior latex paint. A 2x12 is 9" tall. You can paint them any color you like.

pulpo, Sounds more like a "handicap accessible garden" that you're looking to make. Since you have a back problem you may want to reconsider applying hypertufa. It can be very labor intensive building the frame sturdy enough to hold that much soil, plants & water plus the added weight of the hypertufa. Not to mention, applying a wire screen to the wood frame to help hold the hypertufa in place. Regarding what is underneath these boxes, you may want to use mulch or stone. There will be drainage from the box above and it's a pain to try to weed around plants that are planted underneath the boxes. Whatever project you go with, keep us posted on the outcome. Billie

Billie,

Although it does indeed sound like a handicap accessible garden, its design is not because of any hardship. My back is fine (knock on wood) and I should be plenty strong to build hypertufa.

I simply want an my garden elevated to keep it away from animals, allow me to lazily tend it from a standing position, and allow me the opportunity to plant a shade tolerant grass beneath it - which I believe will look far superior to a traditional SFG on the ground.

The monkey grass around my home grows so thick that the weeds have never been able to appear. Hopefully I would be able to go that route versus stone or mulch.

Any estimates of the final weight of the 2' x 4' x 6" box described, as well as the approximate materials list for one completed box, would be a tremendous help!

Thank you all,

pulpo