Drainage for hugelkultur and how it absorb moisture to let plants last throughout the year.

Hello! I wanna find out if I could add pebbles or rocks as drainage for hugelkultur to help logs and stuff absorb water or rain to keep plants moist without losing water throughout the year. I've seen a video of pebbles or rocks being added to the dug up hole before adding stuff on to it for completion. Could y'all show me some examples of them? Please reach me if you need me. Bye bye!

To me, adding pebbles and rocks might help with drainage though ...

If some folks have a drainage problem maybe it is something else that needs to be addressed.

The way I understand hugelkultur is that the wood will absorb excess water and release the moisture when needed.

If in an area where drought is more of a concern than drainage, I would dig out the topsoil from both the bed and path area,  and set it aside for putting back on top of the hugel. I’d then dig down for both the path and hugel base low enough to receive runoff in major rain or snowmelt events from the adjacent area. If a level sill is not in place somewhere in the catchment, always allow positive drainage at the surface on at least one side to prevent a hugel from becoming a floating dam, which could be hazardous. I’d then start the hugel wood down in that catchment basin, layering alternating wood and soil thinly, then 6” of the best topsoil and compost you can if hoping for much in the first season. I would fill the path with woody debris topped with woodchips. This will give the soil a spongy and well aerated base for both absorption and drainage. I have a terrace with such hugels and paths that gets about 75,000 gal per year into the terrace soil on a ridgeline below my house. This has never overflowed due to rocky fill at the base of the terrace, but I have also never seen outflow from the sides. What goes down just feeds my aquifer and springs below.

To start with, I have no idea.  I've never added rocks to my soil by choice, but I've already got a ton of them. ;)

The only times I've seen anyone add pebbles or rocks into a hugelkultur bed was in suburban raised beds trying to fill under or around logs to avoid any possible sinking in the bed as air spaces fill in.  I've always avoided that by layering soil with logs.  (Add a layer of logs, pack soil around it, lather, rinse, repeat). Then putting about 12" of topsoil on the top of it all.

I've not heard of needing to improve drainage, but maybe if there is a really claggy, clay soil on the top of a bed?  Generally the soil on top of my hugelkulturs don't need additional drainage, and I'm on a low-perc soil.

My soil is full of slag and few rocks right now almost all sandy. How do hugelkultur react to urban soil? And do we need another layer of new soil in case if the soil is too contaminated to use? Thanks!

Blake Lenoir wrote:My soil is full of slag and few rocks right now almost all sandy. How do hugelkultur react to urban soil? And do we need another layer of new soil in case if the soil is too contaminated to use? Thanks!

I would use the soil you have, maybe pulling any slag or other undesirable stuff, and then add either a layer of topsoil or just use planting compost in a six inch layer on top of it.  It'll work its way in over time as the wood starts to break down, but the drier nature of your sandy soil may slow down the time it takes to get the wood good and spongy.  That'd depend on your rainfall though.

You could consider throwing something in that'd jumpstart mycology in the wood like a lot of spent coffee grounds or some raw manure or something else?

Could we add mulch to our hugelkultur for enrichment of soil and the organisms that benefit from the material we added to it? How do the lasagna layer and logs work under that pile of dirt to speed up the moisture that sponge its way to the roots of our crops for better growth and health?

Blake Lenoir wrote:Could we add mulch to our hugelkultur for enrichment of soil and the organisms that benefit from the material we added to it? How do the lasagna layer and logs work under that pile of dirt to speed up the moisture that sponge its way to the roots of our crops for better growth and health?

I've never really lasagna layered, but I have added some additional organic matter into the piles of logs I place into my trench, then place my branches and slash above that before filling in and adding the topsoil layer.  I try to keep it out of the initial root zone since I'm usually using raw stuff (usually fresh ruminant manure, I've got plenty when I muck my barn in the spring).  I rely on the soil-beasties to mix and turn it through the first year, and the fresh logs will absorb some amount of it as they start to break down, then release it over the years.

That being said, my first using raw manure additions are only about six years old, so I would argue that I don't have any long-term data yet.