My first attempt at hugelkultur - Can this project be salvaged?

I have a medium-sized urban yard.  I understood long after I bought this property that it is poorly laid out.  There is a large stretch of grass west of the house which gets very little sunlight, and a deck on the north side (just above ground level) which gets way too much sun, and so was basically unusable.  The deck isn't very deep- it used to go all the way from the (north-facing) back wall of the house to the fence, the yard's northern border.  As the part of the deck agains the fence was basically useless, I pulled up about two feet wide of deck boards along the fence, built a long narrow raised bed, filled it with logs, branches, and decaying leaves, watered it down, topped it off with some soil, and hoped it would turn into a hugel bed.

Someone who knew something about hugelkultur saw it and commented on the fact that it would lose too much humidity because of the boards all around.  I had't thought of that.  Also, I tried to pile the material up too high.  It was quite steep, and so rain washed away most of the soil.  The plants I put in last year (beans and clover) never amounted to anything. My broth suggested that I add another layer of boards around it, which would hold soil in, but I'm skeptical.  

Was this project a bad idea?  Hugel beds aren't built with boards around them for a reason.  I understand that now.  Can this project be salvaged?

(This might be difficult to imagine.  I'll take and post a picture of my hugel box this weekend.

Hi! So, I have cinder block 2' raised beds. Year one I literally built it around straw hay bales. The soil layer was thin and the growth/yield was pathetic. But then, the following year I added about 6" compost and fertilized based on deficiencies. I got a good but an aphid problem late season because that's when the carbon nitrogen ratio flipped to too much nitrogen. As the organic matter decomposes, I have to keep adding more compost to keep it full. I'm getting better at doing this cheaply without sacrificing quality and yeild. So far this year everything looks beautiful. It sounds like you need to adjust some water flow patterns, adjust your soil, but doesn't sound like your out of luck, but I can't see it from here. Good luck !

I think there is room for some improvement. I see your profile says CA, and you talk about getting too much sun to use part of your yard, so I'm guessing you're somewhere in sunny southern CA. Most of the successes I hear of from more arid climates involve at least partially burying the hugelbed so that the wood is placed into a pit instead of laid on the surface of the soil. That's how I've done it with mine. My results are finally getting good enough (after nearly three years) that I've been tryign to psych myself up for digging another bed.

Digging a pit also has the advantage of giving you a good source of soil for burying the above ground portions.  You should be able to fit this into the same space you're currently using. Unfortunately, I don't know of any easy way to do this. It would involve moving all your materials out of their current spot, digging the pit, stacking the materials in the pit, and then using the excavated soil to finish covering everything.

From your description I'd say that you may lack depth of soil.  It is recommended by many to have a really good depth of soil above your woody matrix so that your plant roots are not competing with the wood for nitrogen (so six inches minimum for many plants and probably better to have a foot or two; many plants have feeder roots and water tap roots this deep.  The wood is supposed to get wet (and so should be wetted before burying, and the deeper the soil is above it, the better it is at staying damp) and get fungally dominated, and then the fungi and moisture through the fungi, and capillary action become part of the soil system.  This is how the soil is boosted, both micro-biologically and with a positive water cycle.  You can build a hugulkulture (mound culture) or buried wood bed, but you have to allow time to work on (rot/decompose) the wood, for the soil community to establish in order to have results that show it's true potential.  Huguls can be built in containers, boxed raised beds, or whatever, so that is not necessarily the problem, unless your are dealing with extreme aridity or excessive drainage.  It could be that your location is too dry and hot for above ground hugulkultur, as Cassie wrote, but the other issue is probably soil depth.  

Thanks to everyone for the encouragement.  I know that my mound isn't deep enough or wide enough.  The box is 15 inches deep and 33 inches wide.  I'd stacked soil (steeply) on top of the mound last year, but there obviously wasn't enough for the plants' roots.  And adding more soil on top won't help, cause it'll be washed away by the first good rain.  I've seen straw used as mulch on hugelkultur, and I'm sure that could retain the soil, but in my yard, mulch would be a slug magnet.  I was considering adding another board to make the bed higher.  I hesitate because of cost and also because I now understand that all this wood lets the water evaporate, so it's somewhat counterproductive.  (I hadn't thought of that when I planned this project.) But another board would allow me to add soil and compost on top.

Someone said that I might remove the materials and dig underneath, but that's not a possibility.  My yard used to be part of industrial land, and so there's concrete under there.  That's why I figured I'd build up.   I am looking at moving a shed that's sitting in the only other sunny area in my yard.  Once/If I can manage that, then I want to build a proper hugelmound in that area-- a mound that will start in a trench so that it's partly buried and retains moisture better.  

So the way I see it, I either need to invest in some more boards in order to add and retain soil, or else I need to remove some of the height ( soil, leaves, and branches) off my mound and add a good layer of compost and soil.  

By the way, I'm in Winnipeg, which is zone 3.  

Here's a question for Amit:  how do you know that you have too much nitrogen?  I thought you'd need lots of nitrogen in order to decompose those branches.  And is it the excess nitrogen which attracted the aphids?

And another question...  I was watching a video of a talk by Paul W. about hugelkultur, and he made cedar sound like the worst wood for it.  He was talking about wood for burying.  I knew that cedar wouldn't work because it just wouldn't break down.  And that's why I used (expensive) cedar to make my box/bed:  because I wanted it to last.  But he was saying that plants don't like cedar and simply won't grow against it.  So we can add that to the list of mistakes I've made.    

How much of a problem is this?  Can my hugelkultur cedar box still work reasonably well?  Or should I take it apart now and avoid the heartbreak?

While cedar resins are a bio-cide to help to naturally preserve their wood in damp environments, this does make them somewhat ideal for certain purposes as rot resistant members.  Plenty of raised beds are built from cedar boxes, but while the cedar is still resinous there may be some harmful interactions, and so this is definitely a possibility.  Tomatoes, in particular, did not like being in the boxes from what I have noticed at a place where I used cedar.  From what I gather, as the cedar gives off it's resins and the wood gets more gray, the problems associated with the resins decrease.  I had no problem growing greens and many flowers in cedar boxes right from the start.  

Another question for Amit:

But then, the following year I added about 6" compost and fertilized based on deficiencies.

How do you know the deficiencies in your soil?  What signs do you look for?

Jean Soarin wrote:Here's a question for Amit:  how do you know that you have too much nitrogen?  I thought you'd need lots of nitrogen in order to decompose those branches.  And is it the excess nitrogen which attracted the aphids?

So, yes- you need nitrogen to decompose carbon, or more specifically​, the microbes do. If you have only enough nitrogen for them, your plants will be small, leaf growth minimal, early and small flower set, and the lower leaves yellowing early.

As stuff decomposes, the nitrogen otherwise bound up in the wood stuffs is released. This can, as in my case, create excess nitrogen. To much nitrogen is visible by large dark green leaves or lots of vegetative growth, poor flower or fruit set, and aphids. The only time I have ever had aphid infestations is when I over nitrogened. T
Yes, they are attracted to nitrogen and suck the toxicity out of the leaves, in my opinion, but also make me eating those leaves more difficult. If that isn't enough, signs of nitrogen overdose, you can also run a soil test with a chemistry set. They sometimes sell them at garden places here, 40 tests for $10.

I should also mention, like many nutrients, soil moisture affects plant uptake. So, too dry or sopping wet will make nitrogen unavailable to the plants and you'll see false signs of not enough nitrogen. The difference is after a while with water imbalance you will probably also see wilting. Before that happens though, stick your finger in the soil and see how wet it gets.

The science says that usually by the time your plant is showing deficiency signs, there's at least some yield loss. (Not that I don't see these things daily in my own backyard 😁).

Jean Soarin wrote:Another question for Amit:

But then, the following year I added about 6" compost and fertilized based on deficiencies.

How do you know the deficiencies in your soil?  What signs do you look for?

I have a secret chart. I take my garden tours and inspect my plants and if they look funny, I take my chart to them to try to figure out why, then I fertilize accordingly... Okay, it's not that secret. Here's some like it:

https://bigpictureagriculture.blogspot.com/2015/12/plant-nutrient-deficiency-leaf.html?m=1

Thanks SO much, Amit.  I wish I'd discovered your secret chart years ago.  But beware, that's a secret that's not at all safe with me, as I will definitely be sharing it with others.

J.

I think a hugel/ raised bed hybrid would be fine, so long as it was deep enough.

Awesome! Share the knowledge. Infect brains!

So I ended up adding another 6 inch board to make the huge-bed-box higher, and used up a lot of water watering everything down as much as possible.  I have three pails of old coffee grounds that I'd gotten from a coffee shop last fall, but never used.  I was wondering if there's still nitrogen in those, or does it deplete?  (They were sitting outside in a shed in a cold zone 3 winter.)  Also, is there such a thing as too much coffee grounds in a hugel bed?  I'm wondering because I hadn't used rotten wood to build my bed.  I didn't have access to any.  I used what I could find, which was dry branches and a recently-chopped down Manitoba maple.  I also used a lot of old leaves.  Some of the leaves decomposed quite a bit, but the top of the pile was just dried out.  I've tried to change that today with a lot of watering.  So I'm thinking that since the wood has a long way to go before it rots, lots of coffee grounds would speed up that process.  Is this how it works?  Or would I be putting in too much nitrogen?  

So to recap, here are my questions:
1- Is there still nitrogen in seven-month old coffee grounds?  
2- Is there such a thing as too much coffee grounds in a hugel bed?  If so, how do I know how much to put in?

More questions...

Last year, I hadn't put enough soil on my hugel bed, the sides were too steep, and rain just washed most of my soil away.  So it's a lot less steep now, and there's more soil.  Which vegetables would you recommend growing the first year? There's a lot of wood and some leaves under there which have yet to decompose.  I was thinking of planting some nitrogen fixers like bush beans, peas, and asparagus peas mixed in with clover mixed in as a cover crop.  But do I need nitrogen fixers if I have plenty of coffee grounds?  I can't use mulch, because slugs are really problematic in my yard.  I know I can't put in anything with deep roots because the soil isn't too thick on top.  Comments?  Suggestions?