Except by keeping water focused on the rootball, you don't encourage expansion of the roots. This is simply about making berms, and if your berms are a foot apart, that's how far your roots will go. For most of my crops, the roots expand much farther than that. So for plant survival and water conservation, this is a credible strategy. For optimal production, it may not be.

This is a great idea, Zach.

My garden topsoil is less than 12" deep. That is, if one could call the gravel I have to use "topsoil." And, the ruler has shrunk.

Preparing beds, when that was more common (predating the tractor guy) was only to 8+". Never have I started a garden where I seemed to have more than 8" of topsoil to work with. Additionally, I'm not into heavy lifting of dirt at the end of a stick (shovel). And yet, digging out beds, composting in place, and permanent paths with deeply dug soil between them - always seemed best.

The logistics in creating a waffle garden is a confusing proposition, given how precious that topsoil is to me. Digging it out and leaving it on my permanent paths - oh my!! Moving it into a wheelbarrow temporarily while I move subsoil onto the path seems to be the alternative. I'm giving that some thought. It has to be on a fairly small scale just because of the work involved. The tractor guy has to be locked out.

It seems very sensible to conserve irrigation water. Here, annual precipitation is less than 20" and most of that is outside of the growing season. A summer rainfall of 1/4" is a big deal. We go through week after week with no rain during the summer. And ... it doesn't take much effort for me to see sprinkler water roll off my beds and into the paths, carrying some of that good soil with it.

Steve

That is a good way to keep water where it is most needed. I expect the depressions would also cut down on evaporation from the soil and transpiration from the lower leaves, too. Both would give a bit of help in arid conditions.

I like your side by side comparisons with the squash. The difference is easy to see. My squash will likely look wilted this coming week. Even though our yearly precipitation amounts are much higher than yours, none is in the forecast for the next 10 days. And temps are predicted to be over 90F every day - unusual for us.

I haven't ever heard of this but I think it is a great idea for low-rain areas. The San Joaquin Valley gets about 10" of year where a lot of the Nation's vegetables are grown and all is heavily irrigated. I don't suppose this would work on an industrial scale, but is a great idea for a smaller garden.

I've read of sunken gardens used in more arid climates but the waffling part is new to me. Very interesting side by side comparisons. For those with less than ideal soil, I wonder how well berming up the soil around the garden would work, as opposed to digging down to create a planting space.

Rodney

Steve, that much top soil sounds good to me. It takes a long time to get to that level here on the high plains east of the mountains. Most suburban areas the only topsoil that exists is what came with the grass sod. It's a several year project to have garden soil. Hence the reason most people import soil and make raised beds. Though it seems to me having read garden forums for some 15 years the people with raised beds are frequently the ones posting about problems. I'd rather deal with the mineral soil that's here already.

Zach, very good experiment basically side by side. But why not use mulch also?