Feedback Wanted: The Grow-Cano

While working up at the Lab today, I considered how to come up with a built structure geared towards growing plants, very much like hugelkultur. Personally, I'm looking for something not as large as a typical Wheaton Labs hugel, and is easy to maintain and keep everything in reach for the average person (or the lazy person, kinda like me). I checked-in with both Paul and Fred about this, and they admitted they haven't seen anyone else trying something quite like this, so I'm checking in here at the forums for feedback.

I currently call this the Grow-Cano (think "volcano"). It's a mound about six feet tall, 12 feet wide, and has a center column comprised mostly of wood, with a cap of about a foot of gravel. The general idea is that you irrigate the mound by dumping water on the gravel cap. This results in the water infiltrating the center of the growing mound, with the intention of having it permeate the entire thing. It's made entirely of natural materials, and it will persist through both the hottest and the coldest times of the year without damage (like those clay pots that people recommend time and time again...).



Questions for you:
- Do you think this is a horrible idea? If so, then what makes you think that?
- Has anyone else done something similar?
- Do you see any potential problems that ought to be addressed for the next version?
- Finally: thumbs up, thumbs down, or ehh... ?

Thanks for your input...!

I think this is a great idea. I could be wrong. We won't know until you try it!

If I'm understanding correctly, it's basically a small hugel with dedicated watering spot for wicking action watering?

I think a key will be filling the core, especially around the wood, with very absorbent leaves and compost or soil. That should help it get up and running asap I would think.

Be sure to put some lava rock or pumice in there.

Grow-Cano sounds muy bueno!

A vertical hugel?

I'm intrigued. The wood (once it turns punky) will act as a sponge in the core at least in theory.

I wonder about shrinkage over time in the core and how the mound will respond. I suppose in time the whole thing will fall inwards to a degree and just become a slightly smaller mound.

In my mind, it is worth exploring.

What comes to mind to me is that perhaps this is to the same effect as Mr. Trotter’s hugel paths (https://permies.com/t/157279/Hugelpath). Dig down and hill up on the beds and keep adding mulch in the paths. Then when rain comes the paths soak in moisture, and they are in the right place (in the trench or the path) so that they fill up.

I could see the gravel becoming an issue for if you ever wish to put a spade into the mound. It might be just as good to have wood chips or woody debris at the top.

There’s also the issue of getting on top of the pile to pour water in. If one were to have deep mulched (or hugeled) paths then the water would flow into the appropriate section and not need to be carried up a slope. But, if you have water stored higher than the cone (or pressured) then this would not make a difference.

These are just the thoughts that come to mind. I am interested to see what will come of it!

Maieshe Ljin wrote:I could see the gravel becoming an issue for if you ever wish to put a spade into the mound. It might be just as good to have wood chips or woody debris at the top.

I'd decided to opt for gravel to "cap" the center so there's more of a chance that it will stay clear of organic matter and growies to make it easier for irrigation - at least at its inception. Over time it might prove problematic, as you say, when I want to renovate/doctor it. We shall see.

Thank you for the link to the hugel trenches thread...! Well worth a look and inspiration. Initial efforts seem to have been promising with those.

Maybe I could set a fire at the center of the grow-cano to generate some bio-char in there? That seems difficult to monitor/standardize, though. Would be fun to see, I think. :)

Neat design!
I think things growing in the center is a good sign.
You could even seed the wood core with nitrogen fixers.
Chop and drop as needed.
If you really don't want anything growing up there maybe use a big flowerpot/olla or a bucket with a slow leak ?

Seems worth trying. I'm imagining twenty years in the future, the wood has rotted substantially and the gravel is now all through that center column. What do you do then? Is that an asset or a liability?

Interesting idea. It reminds me a bit of a 'slow' banana circle - central organic material feeding outer hungry plants. An alternative to gravel may be just to have twigs sticking out the top. If they are proud of the surface they are more likely to stay clear of 'growies' and will not make a plug of inorganic material.
I wonder whether feeding it with grey water (if you had enough head of pressure) would work, or be desireable? I gather that is one of the functions of the banana circle. I wonder what other functions one could stack?

I'd substitute chunky biochar for the gravel if I wanted a watering channel that wasn't prone to clogging up. That way, when it comes time to decommission the thing, you don't have rocks in your otherwise magnificent soil.

Phil Stevens wrote:I'd substitute chunky biochar for the gravel if I wanted a watering channel that wasn't prone to clogging up. That way, when it comes time to decommission the thing, you don't have rocks in your otherwise magnificent soil.

Ooh, good idea! Make it uncharged to keep plants from growing in it too.

I think it's a great idea Stephen!  I'd consider not having the channel go all the way to the original ground.  Irrigation may just go down there and have trouble wicking back up to the top half of the growcano.  Maybe have it only be 2/3rds the total height of the growcano.

You could maybe also consider a layer of sticks in a spoke pattern at the bottom of the irrigation channel to help water work it's way outward in the mound.

Thanks to everyone for their feedback so far...! I'll make some revisions to the initial plan as follows:

- hole about 2/3 the way down into the mound, though still full of mostly wood
- wood chips and char as the cap of the hole at the top

There's a mound where some Boots had dug a "crater" at the top of it, and I think this will be the place I will start a prototype. It was actually looking at that mound in particular that started me thinking in this direction. I checked in with a couple former Boots who had seen the same site, and they also gave me some feedback in a similar direction. So outlook is good.

Again, I appreciate everyone taking the time to drop a note, some questions, or additional ideas in here. Thanks!!!

I don't think it's worth pursuing, as the majority of roots tend to stick around in the top 30 cm or so of soil, right?    

Assuming this root zone as the target, I perceive it will take too much water to first saturate the entire wooden core, and then slowly percolate outward horizontally (hydraulic pressure) and downward with gravity all the way throughout the cone to the edges where the plants are, compared with just watering the immediate root zone to begin with and having organic matter nearest the rootzone.

In other words, the volume of the dirt cone is quite large, compared to the top foot or so of growing space, that's a lot of soil to percolate through, requiring a lot of water.

George Yacus wrote:I don't think it's worth pursuing, as the majority of roots tend to stick around in the top 30 cm or so of soil, right?    

A lot of them go sideways quite a bit though - think of comfrey! My comfrey has roots going several feet in both directions. I suspect if there was water there then the roots might be inclined to mine it.
It may be worth selecting the plants on the sides appropriately though, or letting them self select by wildly spreading a selection of seeds and getting survival of the fittest....

Neat idea.
Potential problems : the water doesn't go the way you want.
It can go too deep or not deep enough, it can go sideways, it may have a side that requires more water than the other because of plants, winds or isolation.

How do you see a spiral infiltration ditch?