Desert Hugelkultur Questions- SW CA

Hi Guys,

I live in Agua Dulce, a few miles from Vasquez Rock National Park, located between LA and the Antelope Valley. It's a hot (hottest summer I remember was 113) and dry (average rainfall about 12 inches) climate with chaparral vegetation dominated by junipers, yucca, and schrub oaks, and annually mustard and foxtail's.

There is a horse trail running up a hill on the side of my property which collects a lot of rainwater and sediment, bringing it onto my property each year. To help, I built 4 15-60 foot swales (about 2 foot deep x 3 foot wide) on contour along the hill side. With the two feet of dirt I dug out of the swale, I made a mound in front of the ditch and used it covered up a small amount of random pine and other wood I had layed there (I think I added in some pepper tree I learned later is bad for hugelkultur, anyone know just how bad??) Currently I am in the midst of converting them into 6-7 foot tall hugelkultur beds to try and absorb all this water and hold it in for plantings.

I began converting one of these swales into a bed already and have filled it with some of my extra firewood and then alot of dry branches, twigs, juniper and shrubs a neighbor cleared. This woody pile is about 3 feet tall by 3 feet wide. I then added a 8" layer or so of loose alfalfa hay with goat manure that accumulates in barn, hoping to add some nitrogen, and to act in place of the traditional layer of upside down sod which is only available commercially out here. However, I recently discovered access to lots of large stumps (some are 100's of pounds), firewood sized pieces , branches, twigs, you name it, that a friend wants cleared. Is it too late to put the large stumps on this pile? I'm wondering if they will take to long to rot in my dry climate. With the other swales I was planning to partially bury the stumps in the swales and use smaller pieces branches above, but I am unsure how much wood, of what size, is ideal. In my desert hugelkultur, how much wood should I use relative to how much branches twigs, "sod" and soil I use ideally?? My soil to cover the wood pile also is also pretty poor and sandy and becomes a layer of clay after a few feet. Should I mix it with compost or something? Get new soil? Also are there any special considerations when doing hugelkultur is an desert climate? Do I want a wider based bed so to avoid drying out I think would be a problem in a narrow bed, etc? The wood I'm using very dry and the farmers almanac predicts .6 inches of rain in the next two months so should I water the bed as I build it up to get water holding benefits planting this season?

Also I have free access to several truck loads of composted dairy cow /sheep manure, and have practically unlimited availability of composted horse manure, alfalfa mulch, and straw and some goat manure.

My general plan for the untouched swales goes add 3 feet of stumps, then 2 feet of braches/twigs/leaves, then a foot of 3/4 composted dairy cow/goat manure mixed 1/4 alfalfa mulch. Then I was going to add a foot of native topsoil. Blend this into the compost beneath a little, cover with alfalfa mulch and plant. I have a good amount of extra tomato, squash, watermelon, lima bean, sunflower, and corn seedlings I can plant their too, I dont really expect them to survive with summer coming up with no water at al but I would love to be wrong. I also, could bring up a hose or soaker hose to the area. I was thinking a soaker hose under mulch behind the first swale would trickle down and help it all during the intense summer drought and heat. I also really want to plant alfalfa, millet, several fruit and legume trees, and a lot of the pioneer plants from the "Greening the Desert" series, which Geoff Lawton’s used on the site, to really get the system where I think the veggies will thrive. I already have the pig's face plant on the property which I just have to take cuttings from! Also, I have apple red I feel would be a very similar plant.

Any suggestions/comments/improvements? What would you guys do with these material? I'll try to add some pictures soon.

Been doing research on this website for a long time now and it feels great to be finally building my first hugelkultur!
Thanks so much,
Sam

Also I wanted to include the list of pioneer species fromGeoff Lawton’s Greening the Desert. The following is from his website, I believe.

"If you came to a site like this and just started planting typical fruit and vegetables, you would fail miserably. Conditions are far too harsh. Without pioneer species (like these listed below) first setting the stage, the show just would not go on….
• Leacaena: a fast growing, medium size and life span tree; a very heavy nitrogen fixer and very high quality animal forage that coppices and pollards very well.
• Sesbania sesban: an extremely fast growing small tree with a short life span; a very heavy nitrogen fixer, grows very easily from seed.
• Albizia lebbek: a slower growing, long-term, large canopy, long-lived shade tree; a good nitrogen fixer and very drought tolerant.
• Tipuana tipu: a slower growing, long-term, large canopy, long-lived shade tree, with excellent filtered shade form for food forest canopy inter-planting; a good nitrogen fixer and moderately drought tolerant. Will coppice or pollard.
• Prosopis: a medium to large tree, long-lived, a good nitrogen fixer, a good forage including the pods which can be human food; coppices and pollards well but is very spiny and is usually pruned to a high standard to reduce human contact with the spines, unless being used as an animal barrier hedge or for firewood production as it is quite good stick fuel for rocket stoves. Extremely drought tolerant.
• Aciacia Farnesiana: a small, medium-term nitrogen fixing tree with food, medicinal, dye and perfume uses; also a thorny barrier plant. Very drought resistant.
• Poinciana: a large and beautiful flowering and exotic leaf form, very wide canopy long-lived nitrogen fixer that will coppice and pollard. Quite drought tolerant.
• Acacia Saligna: a small medium-term nitrogen fixer, fast growing, good fire wood, very drought tolerant.
• Bauhinia: a very beautiful flowering plant with an unusual leaf, a slower growing, large canopy, long-lived shade tree; a good nitrogen fixer and moderately drought tolerant. Will coppice or pollard.
• Honey Locust: a long-term, medium-size nitrogen fixer that is very thorny; will coppice and pollard and is very good firewood and a very good bee forage.
• Jerusalem Torn: a medium to large long-lived tree, a good nitrogen fixer, small thorns, very hardy with light shade canopy.
• Casuarina Torulosa: a fast-growing, long-lived, tall, slender form nitrogen fixer and phosphate fixer through fungi relationship; a very good wind break tree and excellent firewood.
• Cassia: a small, local bush cassia that is a medium-term nitrogen fixer that can be cut for mulch.
• Tecom Stans: a medium-size and -term fast growing, very hardy tree that can be heavily coppiced or pollarded for mulch. Not a legume.
• Pig Face: a succulent ground cover that insulates the ground from the intense heat, reducing evaporation and trapping organic matter and wind blown nutrient, creating a much improved topsoil environment. Extremely drought tolerant."

My neighbor has pig face so I just need to take some cuttings Anyone know of a supplier of these seeds or possibly started plants? Anyone know if apple red would work equally well? It looks similar and I have tons that seems to be greatly improving the soil in a section of my yard.

I live in Lancaster, Ca.  I have an acre of nearly flat land.  To save water, I wanted to build a hugelkulter.  Reading posts here, I wonder if the top of mound should be below grade?  Afraid winds will dry mound out.  We get 20+ mph winds every afternoon with 100°+ temps.  I have block wall fencing to help.  I understand I’m going to have to irrigate, just hoping to reduce how much.  I was wondering how your experiment in Aqua Dulce turned out?  Did you build mounds above grade?  We get under 10” of rain a year, almost all in the winter.  Thinking of adding more green matter to pile to assist with decomposition.

My soil is a mixture of cliche and sand.  Pretty sterile.  

Some of us in dry climates have determined that, for us, buried wood below grade works better than hugelkultur.  https://permies.com/t/52077/Buried-Wood-Beds

Similar wind and rainfall but cooler temps typically, my limited experience has taught me that it's important to at least cover the sides(like a traditional raised bed), the sepp holzer style definitely capable of good biomass growth but tend to dry out on the sides, good thick mulch is definitely still important with hugelbeds as any other for moisture retention

I have been doing trenches with the hugel material underground, and it works like a charm.  18" is good, but shovel depth works if that's all you can do.  If you can do it deeper, absolutely do it, but it's hard work, especially in the summer.  I start a trench, fill it, but leave about 6 feet open (covered with mowed weeds so the soil won't dry out) to keep filling as I get more limbs/logs that I soak in water.  That way I'm only digging 6 feet of trench at a time, and it's pretty easy.  

When I tried a mound the wind dried it out and the voles/gophers got up into it, put wind tunnels in it and the mound was helplessly dried out.  Very discouraging because it's only fun to build the first mound, not have to try to fix it over and over again.   I found, too, that growing in mounds is difficult where there isn't summer rain because it can take years before the roots get below the real soil level, (for perennials), and I think that's where the plants do best anyway.

I don't get any summer rain, but keep the trenches wet with drippers.  I soak the wood first, and fill in around it with manure.  It gets better and better as the years go on, the first year depends on how soaked the wood is.

Sepp Holzer uses a bulldozer, so that gives you an idea of the size of the mound that's needed.  I'm not willing to do that with a shovel and maintain it.

Yeah my first hugelkultur was about 7ft high and maybe 6 or 7 ft wide at base... approx 20 ft long all done toy hand and wheelbarrow... SUCKED! But that bed did do better than my other hugels on that property (also built to Paul's article picture with large logs stacked straight like the picture) and had a lot more wood biomass into it to begin with