good time of year to build a hugelkultur?

Hello!  I am brand new to all of this, so spoilers alert, there will be stupidity.

I saw a post on FB about Hugelkulturs about a week ago, and it seemed like a better use for all the tree limbs and branches, and all the rest of the yard waste I have been keeping for three years until I had enough to make it cost-effective to have it all hauled away.  So I dragged it all from the driveway back into the back yard and am obtaining some tree-trunk sized logs this weekend, with the idea that I can build it now and put a tarp over it until spring planting time, this being Minnesota.  I was going to start construction this weekend, but have a few of questions that might be relevant first.

1.  Is this an overall feasible strategy, to build and then wait six months or so to plant?

2.  If this is a workable approach, do I put the dirt on now, or can that step wait until spring?

3.  Tarp or no tarp?  (the tarp is mostly to keep my dogs out of it over the winter, since technically speaking the backyard belongs to them, they just let me use it)

Thanks in advance for any comments or suggestions,
Judy Flader

Hello and welcome to the forums!

Starting construction now should not be an issue overall but here are some tips that I think would work better than placing a tarp over it all.

I would build it now with the soil and spread a cover crop over it. I would go with a cover crop that would not over winter - a mix of plants could work well but I would focus on nitrogen fixers. Once the frost hits and kills off the cover crop I would add a mulch layer over the top. Something like wood chips or fall leaves. The cover crop and the mulch will keep the soil surface from being exposed which will protect it and unlike a tarp it will improve the soil and help get you off to a good start for your spring planting.

Depending on your weather right now you may need to water the cover crop until it comes up and gets going.

Hope that helps and I'm sure others on here can provide some advice and more information on cover crops.

Thank you, Daron, much appreciated, and I will follow your advice, that will get me started this year after all.  And I always have a LOT of leaves in autumn.

What would you recommend for a "nitrogen fixer?"  That is a new term for me and I will look it up, but suggestions are always helpful.

Thanks ägain,
Judy

Legumanous plants (like peas and beans) can "fix" nitrogen into the soil. They take it from the air and nodules in their roots turn that nitrogen into a form that plants can use. Plants need nitrogen (it's one of the main ingredients in fertilizers). Clovers and trefoils are some other nitrogen-fixing leguminous cover crops that come to mind.

When I made my hugel, I sewed peas and oats as a winter-kill cover crop. The peas grow up the oats, and the oats add a nice mulch on top when they die. Not all cover crops are winter-kill, though! Some have to get chopped and dropped and then mixed into the soil, which is not what you're looking for. Like Devon said, look for a winter-kill one. Here's a useful list of some cover crops and when to plant them: http://cru.cahe.wsu.edu/CEPublications/FS111E/FS111E.pdf. I've got to go to bed, but tomorrow I'll search around more and see if I can find a nice chart that shows what cover crops die at what temperatures.

You'll also notice that some of the last planting dates are pretty soon. Most cover crops get planted in September. You might not have your hugel finished by then! Life get's crazy, and it's really okay to just pile up wood right now if that's all you can do. It does help--and I wish I'd known this when I made mine--to put dirt BETWEEN your logs as you build the hugel. Otherwise, the dirt you put on top will just slowly filter down between the logs and you'll have a LOT of shrinkage. If you don't have extra soil, using any other material (bedding, manure, leaves, grassclippings) will help. Grass clipping will help speed up decomposition (a good thing!), as they have a lot of nitrogen. If you throw in animal bedding or manure (on &/or between your logs), you'll also help speed up the decomposition, because those all also have nitrogen (things decompose faster when there's a good balance of nitrogen and carbon).

I do not know if it's a good idea to have dog poop in it, as I know cat and human poop has a lot of pathogens and need special composting methods. If you're worries about the dogs digging and pooping in it, you might want to tarp it off. The tarp--while sadly plastic--will also help keep the pile a little warmer during the winter months, which will also help your hugel be ready to plant sooner. You could also throw a giant sheet over it, if you don't want plastic. If you lay fencing over it, that might also work well in keeping the dogs off of it. My cats, ducks, and chickens all hate walking on chicken wire. I don't know about dogs, though.

I hope that helps!

Nicole, thank you very much!  All very good tips and info to have.  I never thought of sheets, great idea, I have a lot of extra sheets that are used to cover furniture in the house - yes, the dogs do rule.

I am picking up biggish logs today, for the base. Have smaller stuff and leaves from last year, will need to get dirt, but I can do that this weekend as well. Good to know about the layering, and filling in the holes.

Lots of work ahead, and just me for it, but that's o.k.  I will post pictures of the project once it gets building, hopefully by the end of the weekend!

keeping the dogs, and especially their poop, out of the mounds is certainly worthwhile but I would recommend fencing around it or something water permeable over top of it (the old sheet sounds like a great idea). I built my first hugels this spring and it was kind of late and I definitely noticed significant pockets of dry and infertile soil that have needed to be regularly watered. Another option for keeping the dogs off it would be to just build it fairly steep. I think this is the perfect time to build the mounds, the more moisture that gets into them to start the wood breaking down the happier you will be next summer.

Thank you, Stephen, much appreciated. I do plan to keep any dog poop out of the mound.  I don't know much about manure, but I do know dog droppings aren't the right kind.   I am hoping once the Kugel is built they will stay off it, but if not then it's just a training issue.

Got the base logs picked up from a friend's place south of town ("town" is Rochester MN). He lost 16 mature trees to a storm last summer, so I am welcome to all the wood I want, although I am limited in size to what I can manage by myself once I get them home, where they have to be schlepped up a hill to get them into the back yard.  That part is done for the logs, the dirt is next.

Starting to think I may be insane, but once I get past the dirt acquisition part, the real fun will begin...

Oh since you mentioned manure, if you have access to horse manure it is a great addition to the base layer in my experience. It is so nitrogen rich that it really jumpstarts the decomposition of the wood and should help buffer against the nitrogen consuming nature of young hugels. I've seen with my mounds that the heat from the decomposition can aid some root growth as well, the artichokes we planted in ours are 3 or 4 times as big as the ones that live in the ground at our friends house even though she is the one who started the seed and kept the biggest seedlings for her yard. So, with your location, I think that a rich manure base between the wood and dirt might allow you to plant a cover crop later and get growth further into the winter while also helping to get the decomposition off to a good start so that you've got a rich biologically active heap to garden in next spring.

Speaking once again on manure - I don't really have access to any, but even without manure, the question came up today from my landlord about whether Hugels smell.  It's a valid question when one lives in town with contiguous back yards and not on a multi-acre homestead, about whether the neighbors might complain.  I'm thinking in terms of no smell, that the dirt layer would contain it, but if anyone actually knows, please share.

Thanks.

The hugel won't smell without manure. If you use manure, it probably won't smell, either, as long as you cover it well with some soil--at least two inches. Four or more inches is probably better. You want to make sure that all the poop is covered and that rain won't wash away the covering.If you cover your soil with some sort of mulch, two inches should be enough. I've used horse manure and duck bedding in my hugels, and they've never smelled. The horse manure was stinky until I got it covered, but the duck bedding wasn't (I do the deep litter method, so it might have stunk if I didn't).

One thing to be aware of, if you use manure, is if the animal's feed was sprayed with pesticides/herbicides. Some people spray their horse or cow pastures with broadleaf herbicides. These herbicides don't get destroyed in the animals' guts, and so you end up putting herbicides in your hugel. All those veggies you try to grow are broadleaf plants...and the herbicides will make it hard for them to grow, and what does grow has those chemicals in it.

Super valid point about the pesticides in manure. Try to get the cleanest you can, ask questions, the people who have really want it gone so they won't mind a little work. As to the smell and covering, for a mound the size you are talking about, with full size logs as the base, I would use the manure to fill in the beginning stages and the big gaps.

Thank you Nicole and Stephen, for all the tips, advice and support.  Today I start building, keeping in mind the keyword for successful dressing in the winter in Minnesota - layer, layer, layer!

There are only two things I am sure of - I'm gonna get really dirty, and me and the pups will sleep very well tonight.

Progress pictures to come...

Got a good start today...the logs went down, added fillers of last year's munched leaves and dirt (a mixture of potting and top soil), watered it, then a thin layer of smallish branches, more dirt and watered it again. I have a layer of leafy Arborvitae branches on it just for overnight (to keep the dogs off) and will keep adding layers this week as I can, watering as I need to but we are looking at a rainy week coming up, so getting water into it shouldn't be a problem.

And pretty much done for now, just need to sow a winter kill cover crop...

Daron Williams wrote:Hello and welcome to the forums!

Starting construction now should not be an issue overall but here are some tips that I think would work better than placing a tarp over it all.

I would build it now with the soil and spread a cover crop over it. I would go with a cover crop that would not over winter - a mix of plants could work well but I would focus on nitrogen fixers. Once the frost hits and kills off the cover crop I would add a mulch layer over the top. Something like wood chips or fall leaves. The cover crop and the mulch will keep the soil surface from being exposed which will protect it and unlike a tarp it will improve the soil and help get you off to a good start for your spring planting.

Depending on your weather right now you may need to water the cover crop until it comes up and gets going.

Hope that helps and I'm sure others on here can provide some advice and more information on cover crops.

..................................................
I'm no pro but this is what I did this year.

I did three hugelkultur mounds this year, one of them is a good sized keyhole garden.   I didn't do the fall thing so there was no time to prep the soil other than amending with wood chips and cow manure.  Things grew anyway.

The first one I did I didn't dig deep enough so not enough soil to cover.  Try to dig deep enough to get your soil to cover.  On the first bed I put wood, grass, upside-down-sod and twigs pretty much anything that wouldn't sprout (make sure you put the sod upside down.)  I covered with topsoil and composted cow manure and brodcast an entire bag of wildflower seeds.  It looks like a secret garden.  

The second hugelmound I planted a ton of squash, fennel, beans sunflowers and etc.   All this stuff is spent so I chopped all the stuff up, set it to the side (leaving the root masses) and broadcast a deer mix (clover, chickory etc on top.) I purchased this at tractor supply.  I used the spent veges as a light chop and drop.  

On the key hole mound I planted every kind of vegetable and flower imaginable, some of it is struggling but the soil was poor.  I plan on using more of the clover as a cover crop on the keyhole to amp up the nitrogen, This is a pretty big mound so I planted a Japanese willow (doesn't get very big) right next to the mound.

One other thing that I didn't do right,  pay close attention to where the sun will be in relation to the mound.  I had 15 sunflowers planted on the wrong side of the second mound and the beans grew faster, I ended up pulling the sunflowers because they weren't getting any sun.

It's frowned upon but on the second and third mound I did use logs as a base perimeter, I was able to get a higher more stable mound.  Some, frown on this method.

To winterize I will weed, and chop and drop anything still growing, leave the root mass and cover with wood chips.  I have a bunch of comfrey growing in a certain spot and next year I plan on planting it around the mounds so I have an easy access biomass.    

So this will probably be my last post in this thread.  I have two Hugelkulturs in my backyard now, the first one which is getting nicely covered with the winter rye cover crop, and the second one that I put together last weekend.  It hasn't sprouted yet, and still needs the brick surround, but that will be done in a day or so.  

I am really looking forward to planting in these garden beds in the spring.  Hopefully I won't plant anything as attractive to the neighborhood squirrels - and my dogs! - as the rye, but if so, then I'll deal with it.  

Thanks to all who advised, posted comments, and just generally provided a lot of support, all much appreciated!