Hugelkultur mound shape

This is my attempt to explore the advantages/disadvantages to having very steep, near vertical sides on a hugel mound.  It isn’t an attempt to convince anyone that they should be built with shallower sides, just an exploration of which works best in any given situation.  It seems to me that there are more advantages to a hugel with shallower sides.  I’m hoping to hear from others as to the advantages they see for the two types of build. I don’t have an ax to grind either way, I’m just gathering information.  Any and all input is appreciated.

Advantages to hugel with steep sides as I see them.
1. Smaller footprint as compared to hugel with shallower sides (thanks for pointing this out Mike Jay)
2. Better cold microclimate on North side
3. More mass/organic matter for footprint size.  This can be an asset with regards to retaining water, or a deficit if you don’t have an excess of material

Advantages to hugel with shallower sides as I see them.
1. More planting area for given height
2. Less problems with erosion
3. Easier to build with regards to keeping soil from sliding off
4. More total mass/organic matter for given height.  This can be an asset with regards to retaining water, or a deficit if you don’t have an excess of material
5. Adds ability to walk up to the highest area/create paths
6. I find it more visually appealing.  This is completely personal preference of course
7. Should catch more rainwater than the steeper sides allow

Other considerations...
1. context - backyard or large open field (for example)
2. what you actually want to grow
3. steep slope might make a natural trellis for vining plants
4. Micro climate on south facing slope for plants preferring warmer (dryer) climates.

Michelle Bisson wrote:Other considerations...
1. context - backyard or large open field (for example)
2. what you actually want to grow
3. steep slope might make a natural trellis for vining plants
4. Micro climate on south facing slope for plants preferring warmer (dryer) climates.

Good points Michelle.  I thought about your number 4, but I'm not sure which would make a better climate for the south side of the hugel mound.  My thinking is that the longer, shallower south side may create a better microclimate for a larger amount of plants, but I'm not sure about that.  If you piled rocks on south side of a steep-sided hugel, that should create a warmer climate, but I'm not certain which would have the advantage here.

but I'm not sure which would make a better climate for the south side of the hugel mound.  My thinking is that the longer, shallower south side may create a better microclimate for a larger amount of plants, but I'm not sure about that.

Better climate & advantage is relative.  It depends.  If you have plants that will benefit from the warmer sheltered south facing steep slop, well then that is a benefit.  Some plants will like it, others will find it too hot, too sheltered, too dry etc...  

Many plants will benefit greatly if they are sheltered on a south facing steep slope, like a grape vine growing up the steep slope, but others like a blueberry bush, might find that this environment will not be suitable.

We all have heard the expression "Right plant for the Right location"

On a steep slope, the right plant for the right location might only be a foot away but higher in the slope.  The steeper the slope, the likelihood there are less variety of plants you might want to cultivate.  We all know by observation in nature, that on steep slopes there are less plants / square metre/ yard.

How much rainfall you get will affect greatly a steep slope mount compared to a flat bed.  

An "east/west" mount works differently from a "north/south" mount because of how the sun, wind and rain affects different facing slops.  Then there is the larger natural land formations & plant in the greater area.

A hugelculture mount will be affected differently if in a city (already warmer & protected) than that same mount in the country where it is a flat prairie or it if is on top of a mountain or deep in a river valley.

Michelle Bisson wrote:

but I'm not sure which would make a better climate for the south side of the hugel mound.  My thinking is that the longer, shallower south side may create a better microclimate for a larger amount of plants, but I'm not sure about that.

Better climate & advantage is relative.  It depends.  If you have plants that will benefit from the warmer sheltered south facing steep slop, well then that is a benefit.  Some plants will like it, others will find it too hot, too sheltered, too dry etc...  

Many plants will benefit greatly if they are sheltered on a south facing steep slope, like a grape vine growing up the steep slope, but others like a blueberry bush, might find that this environment will not be suitable.

We all have heard the expression "Right plant for the Right location"

On a steep slope, the right plant for the right location might only be a foot away but higher in the slope.  The steeper the slope, the likelihood there are less variety of plants you might want to cultivate.  We all know by observation in nature, that on steep slopes there are less plants / square metre/ yard.

How much rainfall you get will affect greatly a steep slope mount compared to a flat bed.  

An "east/west" mount works differently from a "north/south" mount because of how the sun, wind and rain affects different facing slops.  Then there is the larger natural land formations & plant in the greater area.

A hugelculture mount will be affected differently if in a city (already warmer & protected) than that same mount in the country where it is a flat prairie or it if is on top of a mountain or deep in a river valley.

Michelle, I agree that there are lots and lots of variables.  I'm just trying to explore one for now :)

Thank you for this! It has made me re-consider my plans for my first hugel bed (more of a hole in the ground at the moment). I was originally planning to make it quite vertical (6' high x 4' wide ~= 70 degrees, 12' long) using pallets with half the slats removed to keep all that soil in.

After weighing some of the considerations above I am leaning more towards a shorter bed (3' high over 4' width) for the following reasons:
1. The pit has already been dug in a north-south direction and I'd like to use both sides for full/partial sun annual vegetables (don't know why I thought this would work with a 6 foot near-vertical wall 🤦‍♂️).
2. The plants I'm planning to grow on it initially are primarily a mix of brassicas, legumes and squash, all of which would likely prefer a gentler slope
3. Less earth to move (my footprint will remain the same either way)
4. I prefer the more natural look

I was originally leaning toward a highly vertical bed because:
1. It would provide the most dramatic micro-climate (not so sure it would work in my favor now, I need heat!)
2. Maximize production for a given footprint
3. Theoretically provide better protection from pests (this is all happening in a creek bottom popular with wildlife of all sorts)


Any advice or feedback would be appreciated!

I believe Sepp Holzer likes the steep ones so that you can walk along and pick things from 2-6' high without reaching over too far.  There's a graphic of a pick-your-own garden where people walk down an alley between two (of many) hugels and harvest away.  The next day you send the customers down the next aisle over.  

While having a pick-your-own operation probably isn't worth adding to the list, the ease of harvesting things without bending/reaching too far could be an advantage.

Hugelkultur enthusiast, is there any type of wood (trees) that would not make good food in a hugelkultur bed?

Scott
earthsun51@gmail.com

Which region of the country are you?  

Michelle Bisson wrote:Which region of the country are you?  

I'm at the southern edge of Northern Ontario, near North Bay, zone 3b.

So here is a question on steep sided hugels. Does anyone have experience with water absorption?

I ask because in doing some recent land clearing, at the final ‘rake it all smooth and purity’ with the tractor rake stage, I ended up with small piles of small sticks and root bits and dirt, which I stacked in a big mound or pile off to the side so I could plant the newly cleared area. The several times I have gone back to the pile to bury compost in it, I have noticed how very dry it is, just under the surface, even after a heavy rain, and my thought was maybe the water is just running off, since the sides are steep, just like it would on a slope without swales.

So while not designed as a hugel, I am wondering if steep sided hugels have this same problem?  Does one need to be sure to thoroughly soak everything while constructing the hugel so it then stays wet?

Great question Artie!  I see water running off my shallowly humped garden beds so I'm pretty sure it would run off a steep hugel.  Looking forward to an answer on that one from a hugel expert.

One way to trap water on a steep sided mount would be to create little pockets/ where you plant. They can be located where the water wants to run down.  You could have some sticks or branches sticking out that can be used to trap hay, grasses, mulch, leaves etc. (you plant this mulch) so that the rains can sink into this mulch layer.  When planting, plant each plant not directly underneath another plant, but in between sort of like when you would brick lay.

You would not want the slopes to be smooth like a metal roof. It has to have lots indentations / rough surface where the water can penetrate.

It would be important to get plants to grow as a ground cover on the mounts, as possible.

when starting out, you might start with plants that can handle dry conditions and then add plants that can handle more moisture as your mount starts to absorb more moisture.

Mike Jay wrote:I believe Sepp Holzer likes the steep ones so that you can walk along and pick things from 2-6' high without reaching over too far.  There's a graphic of a pick-your-own garden where people walk down an alley between two (of many) hugels and harvest away.  The next day you send the customers down the next aisle over.  

While having a pick-your-own operation probably isn't worth adding to the list, the ease of harvesting things without bending/reaching too far could be an advantage.

I think this is very dependent on the plants.  It may work fantastically with some plants.  

Michelle Bisson wrote:One way to trap water on a steep sided mount would be to create little pockets/ where you plant. They can be located where the water wants to run down.  You could have some sticks or branches sticking out that can be used to trap hay, grasses, mulch, leaves etc. (you plant this mulch) so that the rains can sink into this mulch layer.  When planting, plant each plant not directly underneath another plant, but in between sort of like when you would brick lay.

You would not want the slopes to be smooth like a metal roof. It has to have lots indentations / rough surface where the water can penetrate.

It would be important to get plants to grow as a ground cover on the mounts, as possible.

when starting out, you might start with plants that can handle dry conditions and then add plants that can handle more moisture as your mount starts to absorb more moisture.

Wouldn't all of the things you mentioned be easier on a hugel mound with shallower sides?

I've been thinking more about what Artie said, and I have experienced the same thing, but on the smaller hugel-ish things I built, that are more like a round planting mound with rotted wood in them.  I think I will experiment with a new shape to try to help with the run-off, dryness issue.  The end view of the hugel mound would look like my crude drawing.  Please pretend I can do a better job with paint and that the two sides are more symmetrical.

Trace, I've been thinking about reshaping my garden beds to be higher around the edges and flat or slightly sunken in the middle.  Kind of like your drawing.  So I think that would work but it would be hard to fit into a steep hugel bed.

Trace, you are depicting what i thought as the perfect hugel. A volcano with a crater.  That will catch the water. Even making them literally round mounds versus long hugels.

I understand that other factors come in to play from the traditional design ( like wind protection), but moisture must be there to succeed. It may be a thing where local climates dictate the style.

A long hugel with wood below grade might collect and absorb enough water. A long hugel with the wood above grade might not. A crater, it will collect some in either.

There may be instances where higher & steeper slopes might make more sense. For example, if you needed to make a high berm to cut down on road traffic sound and you do not have a lot of ground width to work with.  Then you really have to be creative with your hugel mount with steep slopes: how to harvest water, how to grow on steep slopes, what plants to grow at the different heights, how to make sure that the whole thing doesn't collapse & is structurally sound.  I believe at Wheaton Labs is a good example of a tall steep hugel mount close to Paul's house.