Can I make growing medium by layer mulching with lots of wood chips in Phoenix?

Hello all. I've been lurking, studying and putting many things into practice on my property. We have over an acre just south of Cave Creek that we are working on. Watershed management, hugel beds and woods chips. Lots of wood chips. My friend the arborist is dropping clean chips by the truck load. Most of the back yard is bare from having horses on it many moons ago.
My question is in regards to what can be done to turn it into a good medium for growing. At the moment, we are putting down cardboard and piling about 10" to 12" of chips on it. There is plenty of green material as well as the chips. Maybe 50/50. I'm not sure if this is a good plan of attack. Am I wasting my energy here because the chips will take so long in our climate to decompose. What say you desert dwellers? Shall I continue laying chips, add something to speed the process, or just move to the Pacific Northwest?

I am curious about this as well!

I live south of Tucson and for any wood we have, I've noticed that the only thing which seems to break it down quickly is the termites. But this isn't something you would necessarily want near the house, I imagine. :-/

Steve Nash wrote:Hello all. I've been lurking, studying and putting many things into practice on my property. We have over an acre just south of Cave Creek that we are working on. Watershed management, hugel beds and woods chips. Lots of wood chips. My friend the arborist is dropping clean chips by the truck load. Most of the back yard is bare from having horses on it many moons ago.
My question is in regards to what can be done to turn it into a good medium for growing. At the moment, we are putting down cardboard and piling about 10" to 12" of chips on it. There is plenty of green material as well as the chips. Maybe 50/50. I'm not sure if this is a good plan of attack. Am I wasting my energy here because the chips will take so long in our climate to decompose. What say you desert dwellers? Shall I continue laying chips, add something to speed the process, or just move to the Pacific Northwest?

First, I've got to ask - are you the basketball player?

I've mulched heavy here in Phoenix & on my property in S.E. AZ. using wood chips, compost, & leaves. When it comes to getting the soil going, I've had the most success with leaves. I mulched last winter with dropped mulberry leaves & the amount of life in the soil took off. I went from few worms to at least a dozen in every 5" square I pull up + the soil is always damp & sticky.

Hi Steve and welcome to permies!

My parents used to live in that area (64th St and Dynamite).

Woodchips are great - keep getting them and spreading them on your site - they greatly reduce evaporation from our soils. However, if you want things to decompose, you need water. As you probably noticed, water does not tend to soak into our desert soils very easily. That's why many of us have turned to water harvesting earthworks. These depressions in the ground capture and hold moisture for a much, much longer period of time than anything mounded or raised (like hugelkultur or raised beds) and encourage decomposition. Otherwise, in our extremely dry and HOT climate what you tend to get is desiccation.

Tucson native Brad Lancaster's books and website are a huge boon to our climate and region. Permaculture giant, Geoff Lawton, refers to Brad's books often and he uses these techniques in his dryland projects like the famous "greening the desert".

Here's a couple of pictures and captions from his first book:



The wasteful path to scarcity. The site rapidly dehydrates itself by erosively draining rainwater and runoff away to flood downslope areas and contaminate surface water with sediment. Greywater is lost to the sewer. Costly municipal or well water is pumped in to replace the free water that was drained away. Leaf drop/mulch is also drained away further depleting fertility and water-holding capacity. This leads to a depletion of resources and feeling scared in the city due to the resulting scarcity.



The stewardship path to abundance. This site passively hydrates itself by harvesting and infiltrating rainwater, runoff, and greywater on site, reducing downslope flooding and overall water consumption and contamination. The need to pump in water is greatly reduced or eliminated. Leaf drop/mulch is also harvested and cycled back into the soil and plants further increasing fertility and water-holding capacity. This leads to an enhancement of resources and abundance of celebration due to the resulting abundance.

I also highly recommend that you check out Watershed Management Group. They are headquartered in Tucson but have a Phoenix branch. You can sign up for the Phoenix newsletter here: http://watershedmg.org/co-op/phoenix

I must have the only soil in AZ. that will absorb as much water as you can pour on it.

Wayne - I think you might be right - lucky you! Although over time, I've built up my soil so it will absorb even one of our torrential 2" rain events (a "100 year event") as it did in 2010. Even with most of the neighbor's roof water falling on my property. It was REALLY gratifying because I remember when I first got the property, the soil was so compacted that water sheeted right off of it.

Jennifer Wadsworth wrote:Wayne - I think you might be right - lucky you! Although over time, I've built up my soil so it will absorb even one of our torrential 2" rain events (a "100 year event") as it did in 2010. Even with most of the neighbor's roof water falling on my property. It was REALLY gratifying because I remember when I first got the property, the soil was so compacted that water sheeted right off of it.

Am I lucky? The sandy soil creates a whole bunch of issues including roving gangs of tunneling varmints.
I get jealous when I see swales holding water.

Unless you have weeds you are really hoping to suppress, I would feel free to skip the cardboard.
I just got done spreading 600,000 pounds of wood chips over 2 acres and i never would have wanted to take the time necessary to put down cardboard first.

The soil has changed more in 2 months than I could have ever imagined.

Living in the desert in NM, I was shocked to find that after putting down the chips, the soil stays wet for many weeks after rain or sprinkling.

Thank you ALL for the quick and informative replies! I'll address the questions and thoughts individually and given some more background information on the wonderful journey my wife and I are embarking on in our yard.
Shauna I'm concerned about termites as well. They've been in my house before and I don't anticipate bringing the wood chips any closer than 50 ft. to the house. I'm interested in finding a natural defense for the nasty critters. Anyone have an idea?
Hey Wayne. No I'm not the basketball player. I'm the taller Steve Nash lacking in coordination enough to dribble and drool at the same time. I'll talk to my arborist and see if I can get mostly leaves in a couple areas to do a side by side analysis. As I've stated, the wood chips contain tons of leaves already so I'm hoping it is a perfect mix for rapid decay. The piles are composting quite nicely already on their own. They've been in my yard for a couple weeks now and I've spread only about half of them.
Excellent information Jennifer and thank you for the welcome. I've been learning about water harvesting and Brad Lancaster's videos are fantastic! I'm so stoked to have a watershed management expert coming to the house next week. We have a very large wash running diagonally through the yard. It has created pools that fill during heavy rains so we already have a leg up in regards to capture. These are all natural and my yard has been doing this for the 20 years I've lived on it. We are looking into grey water harvesting and rainwater from the roof as well. I think we typically get a little more rain up here than Phoenix and Jennifer, I could hit your parents old house with a rock from our place.
Hey Mark. I am a restaurant owner and I'm very happy to use the hundred or so cardboard boxes I get weekly for a good cause that will give something back instead of just winding up in a dumpster. And yes, all my vegetable waste comes home with me nightly for my compost piles! This yard has always had huge weed problems. It's nice to kill two birds with the cardboard repurposing. When I first purchased the place, Roundup poison was used regularly and I became enlightened enough to stop using that early on. I even laid down a bunch of salt to kill the weeds,thankfully without success. It feels so good to finally be doing something good for the land. Moving towards sustainability at every turn now.
On the topic of water for the wood chips, shall I put a sprinkler on them occasionally? We've got Scottsdale water until I can harvest my own. The municipal water is disgusting, very alkaline. What do you all think of getting it wet that way? I do soak the cardboard in a trash can filled with water before I lay it down. The stuff is still moist a week later!
Thanks again permie friends. I so look forward to hearing more from you.

Wayne Mackenzie wrote:Am I lucky? The sandy soil creates a whole bunch of issues including roving gangs of tunneling varmints.
I get jealous when I see swales holding water.

Oh man - I thought you meant you had such great soil it was soaking in and HOLDING the water. Meh. No - sandy soil that drains too fast is no fun either.

Steve Nash wrote: I've been learning about water harvesting and Brad Lancaster's videos are fantastic! I'm so stoked to have a watershed management expert coming to the house next week. We have a very large wash running diagonally through the yard. It has created pools that fill during heavy rains so we already have a leg up in regards to capture. These are all natural and my yard has been doing this for the 20 years I've lived on it. We are looking into grey water harvesting and rainwater from the roof as well. I think we typically get a little more rain up here than Phoenix and Jennifer, I could hit your parents old house with a rock from our place.

Sounds like a great place. You aren't, by any chance, near the "camel" house are you?? Your property sounds so much like the area right around my parent's house. Washes, 1.25 acres, horse property, Scottsdale well water....

Is Ryan Wood the person coming to your house? If so, he's a neat guy - you'll like him. Comes from farming stock in Idaho.

Steve Nash wrote:I am a restaurant owner and I'm very happy to use the hundred or so cardboard boxes I get weekly for a good cause that will give something back instead of just winding up in a dumpster. And yes, all my vegetable waste comes home with me nightly for my compost piles! This yard has always had huge weed problems. It's nice to kill two birds with the cardboard repurposing. When I first purchased the place, Roundup poison was used regularly and I became enlightened enough to stop using that early on. It feels so good to finally be doing something good for the land. Moving towards sustainability at every turn now.

Can I give you a gold star on your forehead for this? Using boxes and the waste from the restaurant makes me smile! Are you having any issues with javalinas? They used to love my parent's compost bins.

The only thing I would steer clear of is laying down any kind of salt to kill stuff. Salting will kill EVERYTHING. Historically the victors in battles would salt their enemies fields to kill their crops and subjugate them as slaves. Plus, our soils are already highly saline. Increasing soil salinity is one of the factors driving desertification.

Steve Nash wrote: On the topic of water for the wood chips, shall I put a sprinkler on them occasionally? We've got Scottsdale water until I can harvest my own. The municipal water is disgusting, very alkaline. What do you all think of getting it wet that way? I do soak the cardboard in a trash can filled with water before I lay it down. The stuff is still moist a week later!

Sprinklers in our climate are not the best choice as a lot of water is evaporated during the "sprinkling". It's also not the highest use for your decent water up there. If you wet down the boxes and/or the dirt before spreading out the woodchips, you're doing fine. As you get a more water harvesting landscape (earthworks/infiltration basins), the low areas that naturally capture water will decompose the woodchips faster than other areas. Also, if you do greywater, it will be vented to infiltration basins as well. Using greywater as opposed to potable water to increase decomposition is a better use of our scarce water resources.

Otherwise you can just leave the woodchips and not worry about it. A longtime friend and neighbor got some woodchips about 5 years ago and spread them on her backyard about 8" deep. She did nothing else. Whatever rain fell on them is what water they got. She has about 4" of beautiful soil out there UNDER the 2-3" of chips on the top which are silvery with age. That's just the way decomp goes in our climate. It takes awhile but it will speed up as the soil life becomes more robust.

Keep us posted on your progress and be sure to take a lot of "before" pics - you're going to want them for comparison so you can be amazed by what you've accomplished.

Good morning Jennifer. No I'm not in the camel house. Pretty sure I know the one you're talking about. It's on the north side of Dynamite. I'm actually 1 block north on Peak View and 60th st.
After using Roundup a few years, I was very hesitant to use the salt as was recommended to me. So much so that I used about a quarter of what the gentleman said I should. I'm happy to report that weeds have been popping up ever since so it looks like no harm done. Yes! The Romans sowed so much salt into the Cartheginian fields, they are infertile 2500 plus years later!
Ryan Wood IS coming next Monday. My wife has volunteered with VPA so that is how we got this ball rolling.
The wife is also our photographer of record and will put some stuff together for you all.
Thanks again! Utilizing the resources from my restaurant for good in my yard is an obvious step I should have taken years ago. Better late than never, yes?

Ryan's a good guy - I'm sure he'll love to see your site. And he'll be impressed with your recycling/composting/mulching activities.

Very cool that your wife volunteers for the VPA. I'm actually the one that designed that site back in 2008 (why does that seem so long ago?) and was their class coordinator during that same time.

Looking forward to seeing some pictures and maybe even joining a WMG coop event at your place. Keep up the good work!

Jennifer Wadsworth wrote:

Wayne Mackenzie wrote:Am I lucky? The sandy soil creates a whole bunch of issues including roving gangs of tunneling varmints.
I get jealous when I see swales holding water.

Oh man - I thought you meant you had such great soil it was soaking in and HOLDING the water. Meh. No - sandy soil that drains too fast is no fun either.

I first attempt to drive to the creek in the back - LOL.

Wow - Wayne. That's just crazy!