Vertical hugelkultur & wood chips vs horizontal hugel

Here's a quick comparison of fava beans growing in a hugelkultur bed.  The beans were planted in November, about 4 months ago.

The bed pictured, just beyond the fence, is 12'x3'.  The 4' of the bed on the right was my first attempt at hugelkultur. It has mostly horizontally buried logs with no wood chips dug in. The rest of the bed was dug with vertical stumps and wood chips.

See: http://lowcostvegetablegarden.blogspot.com/2012/10/garden-bed-construction.html. 

No fertilizer was used.

Notice how the fava beans grew much better and thicker in the part of the bed with wood chips and vertical stumps.

Here's a closeup of the favas in the vertical stump & woodchip part of the bed. The stalks are much sturdier and thicker here.

Here's a closeup of the favas in the mostly horizontally buried log portion of the bed.

Hugel hole preperation

Last year I prepared and planted cucumbers and tomatoes in 3 hugel holes with mediocre results.

Just improved/redid the holes this year using what I learned from last year's experience.

In one hole I had put in horizontally buried branches and also mixed in some leaves. It did poorly. Just adding logs into clay soil isn't enough to make a good growing bed.  So I redug this hole out. 2' deep, 2' diameter.

These were the branches I dug out.

Put in vertical stump and branches about 10" to 1' in length. Made sure I left one shovelful depth between the soil surface and the stump. This is so I can easily do a "single dig" in future years, i.e. dig in more organic matter one shovelful deep.

 Then I added wood chips and soil to fill in the hole.  Alternated 3 shovelfuls of chips, then 3 shovelfuls of dirt. This seems like a lot of wood chips, but after just one summer this clay soil absorbs all but the largest chips.

In this hugel hole last year, I just threw in a stump vertically and mixed in a little bit of leaves. The cucumber plant did very well in this hole. The vertical stump seems to wick away excess moisture will keeping the dirt just the right amount of moistness for the plants.  The stump in the ground was from last year.

Added some branches on top of the stump, just enough to keep the wood a shovel depth below the surface.

Then 3 shovelfuls wood chips, 3 shovelfuls dirt, ... After done the pile is 1 foot high. This will be ready to plant in 2 months, mid-April.

I'm really looking forward to seeing what the soil looks like at the end of the summer. This is the first time I've added so many wood chips at once.

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.

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.

Wood chip bed

After seeing how well the hugelkultur beds were doing, I decided to make another bed but with just digging in massive amounts of woodchips.

The idea is to see if you can get a good first year harvest from this and then in future years will there be enough organic matter in the soil so that it becomes a good no till bed.

I dug down about 1 to 1.5' deep, double dig style.  Then I added wood chips to the dirt pile and raked it back in. The bed rose about 1'+ after doing all this.

This picture shows the bed after being prepared.  The "density" of woodchips on the surface, is the same as the density of woodchips added to the entire 1' to 1.5' depth.

This seemed like a lot of wood chips to me at the time.  However now when I dig into the bed to take a look at the soil, it does seem like much less wood chips than I remember.  Next time I'll add a lot more.

The bed was planted in mid June with transplants and direct seeds of corn & pole beans. Here it is on July 10th. So far it looks quite well. The plants are not quite as green as they should be, but I'll be adding more liquid fertilizer shortly.  I have been able to keep squash, cukes, & tomatoes in hugelbeds dark green, so keeping this woodchip bed green shouldn't be an issue.

No compost, no leaf mulch, and no store-bought fertilizer was added.  The only additions were wood chips and HLF (homemade liquid organic fertilizer).