Tuesday, October 30, 2012

Wood chip soil pictures

The garden beds, which had wood chips dug into the soil, did the best this year.
So I decided to dig up soil in them and take a look at what was going on.

Most noticeably was that the plant roots all congregated where clumps of wood chips were buried.

Also very noticeable, there was lots of worms throughout all the soil, soil that had wood chips and soil that didn't.  In previous years I had never seen so many worms. I believe having the wood chip mulch encouraged more worms than the leaf and pine needle mulch that I used in previous years.  I had wondered if worms would feed on wood chips, it seems that they do.

Here are two clumps from the same bed.  On the left no wood chips had been mixed in. On the right lots of wood chips had been buried. Notice the almost total lack of roots on the left, yet these clump were only about 4" away from each other in the ground.

Another soil & wood chip aggregate from another wood chip bed. Notice the darker parts of the soil in this picture. These are worm castings. The soil had lots of worm casting deposits wherever wood chip clumps were, even over a foot deep.

Here I dug up soil from a regular hugel bed (horizontally placed logs).  In the spring I did dig in some pine needles & leaves, but they had totally disappeared.  The cucumber growing in this bed did ok, but not great. Cucumbers growing in the wood chip bed did great. Cucumbers growing in just a clay bed (no wood chips, no hugel logs) did very poorly (didn't produce any harvest).

There were lots of worms and worm holes in the this soil, but it was still thick clay and no where close to being as good as the soil in the wood chip bed.

It seemed the roots did best in soil that was about one-half wood chips!
Quite a surprise.

As another experiment, I had planted a couple seedlings above some wood-chip-only clumps in the soil that were about 3" deep and 5" diameter. The plant roots did not like growing into only wood chips and these plants didn't do as well.

Seeing how well roots did in "wood chip soil", has given me confidence to really go all out when digging in chips. I had wondered what would be too much. But it seems even 1/2 chips, 1/2 dirt is great for the plants.  If I had seen this before I prepared my 4 new hugel beds, I would have dug in even more wood chips. For the 2 existing wood chip beds, I'm digging in a lot more chips now, before planting fava beans.

Monday, October 22, 2012

Garden bed construction

This last summer I experimented a lot with different growing methods in my garden and in containers.
Based on the results, this fall I redid my garden beds using:

1.  Vertical hugelkultur
2.  Large quantities of wood chips dug in the soil.
In small test beds this year these 2 techniques did the best.

Just completed 4 beds, here are pictures of building one.

Dug down average of 2.5 feet. At that depth I hit a layer of pottery-like clay that would be unusable for garden soil.
This bed is 3.5 feet wide and 12' long.

Added wood scraps, from splitting wood, at the bottom.

First layer of vertical stumps, packed closely together.

Added dirt mixed in with wood chips and then put a 2nd layer of vertical stumps.

More dirt and lots of wood chips.

Added a 3rd layer of branches, partially rotted and began building retaining walls from logs and 1/2" rebar.

No pictures, but did add a 4th layer of larger branches placed horizontally on top of here.

Here are 2 completed beds, built with retaining walls.

Also made 2 other beds without retaining walls. Those ones only had 2 layers of logs, one vertical, one horizontal. So they did not raise the soil level as much.

The only cost for these beds was the rebar (~$30).  All the logs, stumps, and chips were free. Lot of digging though.  Didn't get a chance to go to the gym for the last 6 weeks :)

Roughly the top 6" or more of soil in each bed does not contain logs or branches, just dirt and wood chips.  This is to make it easy in future years to dig in more wood chips with a normal shovel if this will be needed.  The soil is very thick clay and I believe I'll need to dig in more chips in a couple years.