Hugelkultur

The sun slanting through our temperate rainforest. It now is finally starting to look the part.

This weekend we finished and planted our raised garden bed.  For the garden we used a technique called hugelkultur (“mound culture” from the German).  This type of farming has been around for centuries and was used extensively by preindustrial peoples in Europe and Central and South America.  Hugelkultur involves burying large amounts of wood and allowing the rotting mass to form the foundation of the garden bed.  The wood provides a number of benefits, including aeration of the soil, rich fertilizer, and water retention.  A number of the accounts we’ve read claim that even in fairly arid climates hugelkultur mounds need no irrigation thanks to the retained water.  Since the topsoil of our most convenient field is gone and we have no well for irrigation, this combination of traits is extremely attractive to us.  We’ll be testing that out during this first experimental year – if it works well we’ll add more beds.

Our hugelkultur lump in progress.

To start our our lumps we’ve been carrying large quantities of wood from long dead trees up to our garden plot over the past two weekends.  The wood should be as well rotted as possible.  Some woods work better than others – cedar and osage orange, for example, are notoriously resistant to rot, so aren’t very good choices.  Pine and fir, two of our more common trees, have tannins which can leach out to stunt the growth of other plants.  We chose logs which had been down for at least two or three years, which should allow the tannins time to leach away.

Our pile of logs before adding the next layers. We chopped up the smaller branches to wedge in the interstitial spaces.

Since wood can consume nitrogen as it rots, we decided to hedge our bets and add a nitrogen source to our piles.  The Scotch broom that covers part of our hillside is a legume, so it acts as an admirable nitrogen fixer.  Lee cut some bushels of Scotch broom and hauled them up to the garden site.

Lee returns from another successful foray into the rich Scotch broom mines to the south.

We placed the Scotch broom on top of the base pile of logs.  We then lined the log pile with large rocks clawed spitting and cracking from the living earth with a mattock.  These rocks will serve to contain the dirt which will be added in the next step, and provide a heat source to keep the soil warmed after the sun goes down.

Kestrel makes some final adjustments before we add the last batch of defeated Scotch broom.

Next we added earth to fill in the cracks between the sticks.  This will give the roots of our plants purchase and allow water retention until all the wood is rotted enough to hold water well on its own.  For this fill we used sod that we had pulled from our other excavations.

Mostly it just looks like a mess.

Once the first batch of dirt was put on we deemed it wise to cover up the Scotch broom with cardboard mulch.  Just in case.

It was very windy this weekend. The cardboard kept blowing away.

After the mulch we added another layer of sod to the mound.  During this stage we also watered the lump well to get the rotting started.

It’s funny how covering everything in dirt makes it look neater.

The next stage was quite like backfilling our fruit tree holes.  We mixed a 50% mixture of compost and loose dirt and piled it about 6 inches thick on top of the mound.  The rock walls helped to retain it.

It’s starting to look almost like a finished product!

The last step was to add another inch or two of pure compost at the top as a moisture retention mulch.  It will also be a nice fertile soil for our seeds to sprout into.

Kestrel puts the finishing touches on the hugel.

And that’s pretty much all there is to it.  Today we finished planting the garden, so stay tuned for updates.

As we were leaving our land after finishing our lump-o-garden, we came across this nicely silhouetted quail.