Building stone hugelkultur raised beds

 There is plenty of information on hugelkultur (pronounced hoo-gul-culture) on the internet. I am going to give a basic instruction on how I built mine. I would suggest you do some research on the fundamentals of how it works before attempting but its fairly simple and with a basic understanding has rewarded us with bountiful harvest for years.

Im going to start with the materials. I use what's available to me locally and make or get most of the ingredients like old wood logs and sticks, leaf mold, compost, worm castings and stones on the property the gardens are located. All the components have acceptable substitutions with a little investigating.

Lets start with the bottom most layer. This is our sponge it helps with water retention and its continued breakdown provides nutrients to the garden for years to come.  I like to use wood logs and not just any old logs but old rotted logs are desired in this case. You will have to research which wood is best and some are not suggested but we have lots of oak trees around us and that's predominantly what we use. 

This wood is too fresh in my opinion (roughly two years old) but about a year after this picture I didn't have a choice and had to use some of it.

Wood pile aging (not ready)

 

These piles are more like what I would suggest. Its over 3 years old and has all the signs we are looking for:

• Looks old
• Bark has degraded almost gone
• Its significantly lighter in weight than you would expect
• It has an almost sponge like feeling on the outside especially if wet (it acts like one too)

Aged wood for hugelkultur raised bed

Pile of aged wood for bottom of raised bed

Another good source of usable wood is branches that fall from trees. This is my collection from a storm. Yes I'm aware the gloves are giving a peace sign.

The next layer is sticks branches and leaves. I put a layer of sticks on top of the logs and cover that with mulched aged leaf mold. Then I put a layer of older aged black leaf mold followed by compost.

Leaf mold aged 1 year

Leaf mold aged 2 years

The end product of my leaf mold is essentially compost. During the three years it decomposes I mix in all types of green materials kitchen and yard waste as well as other amendments like crushed eggshells, oyster shells, coffee grounds, rock dust, chicken poop, and any other helpful additions I can find. Right before I use it I run it through a trommel I made.

Trommel for sifting soil

The compost comes out like black fluffy soil that smells of natures goodness. I used all mine this year so I don't have a picture (i will add one soon) but this is what the trommel ejected. You can see i can probably run it through the trommel again and get more compost if needed.

Ejected leftovers after trommel use 

  

Completed black leaf mold compost is finished when

• By appearance it no longer resembles what it once was. Kind of looks like coffee grounds.
• By smell it has a really good earthy back to the forest essence.
• No more worms the worms that once inhabited the pile have moved on to better piles because they are finished devouring this one.

 So all the above should be used to fill the bottom half of the bed next comes mixing soil for the top half (6 - 12 even 18 inches depending on depth of bed and crops you intend to plant). I'm not going to get into soil making here but just like gardening. It takes a little while to learn but a lifetime to master. I vary the mix as I get closer to the top. so lets say im filling 12 inches with soil. The bottom third will be a ratio of 1:1:3 (sometimes as much as 6) compost(1 part) : aeration(1 part) : dirt(3 to 6 parts) but as I get closer to the top I get closer to a ratio of 1:1:1 or 1:2:3 (compost : aeration : dirt) depending on what I have available at the time. I amend all of this soil progressively with more as I get to the top. My most recent batch had basalt, neem seed meal, crab meal, kelp, oyster shell flour, gypsum, and garden tone. all amended by tried and true calculations to the square foot of soil that I wont get into here but general guidelines are found online.

 

That's all the stuff you need to have in order before you even think about building a stone hügelkultur raised bed (or at least one like mine) and now that I have intimidated all the dispassionate or ill-equipped with all the time and effort required we finally get to build some stone hügelkultur raised beds.  

This post will be finished at a later date busy in the garden currently Check out How it started to see if it inspires you to build your own raised bed. If you have any questions or suggestions this is the best way to contact me at Questions and suggestions