Create your own Sonoran Desert Food Forest

Richard Roati's food forest

There's nothing like having a lush canopy of trees to enhance your life in the desert. Those trees won't just cool your house and yard (and cut down on your energy bill), but they will help cool off the whole neighborhood. Areas with trees are up to 12 degrees cooler than areas without. And those tree branches hanging over sidewalks make a nice place to walk your dog and socialize with your neighbors. 

You've probably seen gravel and cement in too many yards around town. While that may cut back on the water that would otherwise have been used for a lawn, that cement holds in the heat contributing to the heat island effect. Phoenix, with all its asphalt and cement, doesn't cool off at night! That's dangerous for plants, animals and people. Planting trees helps mitigate the heat island effect.

So...we need more trees in Tucson. But what about the water shortage in the desert? How are we supposed to water all those trees? I suggest we embrace our desert surroundings and plant low water, drought tolerant native trees with rainwater harvesting catchment basins. Native trees take little or no water once established. They include ironwood, palo verde, and velvet mesquite (not to be confused with non-native Chilean mesquite trees that grow too quickly and have been known to fall over during a storm.)

You can learn how to build your own basin at the free Rainwater Harvesting Rebate Classes offered by Watershed Management Group or S.E.R.I. 

Here's how my husband Dan (a docent at WMG) made our front yard basin...

First, he dug up two feet of  gravel and pulled plastic out of our yard.

Then he observed where the water flowed when it rained. He noticed that an awful lot of water was coming off the side of the roof and was causing erosion where it fell. So he dug a shallow basin in the middle of the yard using that dirt to build up a small berm with a gradual slope so the roof water would flow at least ten feet away from the foundation of our house and into the basin. (The idea is to slow down and spread out the water so it sinks in.)

Because they are on the south side, he planted three native trees far from the house on the high end of the basin. Then he planted some native bunch grass in the bottom of the basin and filled it with woodchip mulch. The roots of the grass along with the woodchip mulch create a sponge to hold the water longer. As the woodchips breakdown they provide organic matter to the soil that in turn nourishes those trees. How cool is that? 

Did you know that those native trees are also edible?  The ironwood and palo verde have yummy seeds. And dried mesquite pods can be ground into a delicious and healthy flour. As long as we have these edible trees, why not just go ahead and create a desert food forest? If you're gonna use water for a tree, you might as well plant something you can eat, right?  But creating a desert food forest provides much more than shade and nutritional food for your family and neighbors. If you do it right, it will provide a fine habitat and food for local birds and flowers for pollinators. And that makes it a lovely place to hang out.

Dan also created a little mesquite guild in our front yard by planting a hackberry bush under the mesquite tree. The mesquite acted as a nurse tree protecting the young hackberry from the sun. It also added nitrogen to the soil. Nearby is a prickly pear cactus that has edible pads and fruit! 

This year we got to try our first hackberry berries. The little orange berries tasted like a combination of cantaloupe and cucumber. The birds enjoy them too. 

In our back yard, we took advantage of our outdoor washing machine to irrigate low water heritage fig and pomegranate trees in our greywater basin.  Heritage trees are ones that have been here so long that they have adapted to our climate. 

Watershed Management Group also offers greywater classes. 

But my favorite rainwater harvesting feature has to be our jujube basin. We already had gutters and a downspout in place.

So Dan dug a long basin with three mounds along it where he planted jujube trees.  Native bunch grass and horse purslane serves to slow down and sink in rainwater, hold the mulch in place and prevent erosion. Jujubes are a Chinese fruit that look like little apples. Although they aren't traditionally from Tucson, we have found that these trees are really drought tolerant with their shiny leaves. I only watered them every other week in the hottest month of June. And I didn't water them at all during the rainy season. This is how they are doing now....

Coming from another part of the country, the first thing many people want to do is plant their favorite fruit trees from home. Totally understandable. Just do a little research and find out how much water those trees need so you don't overwater or underwater them. Find out how to take care of them in the desert. They may need some shade from our brutal summer sun and mulch to keep the moisture in the ground longer. Come up with as much water as you can from greywater (washing machine, bathwater, air conditioner condensate) and rainwater harvested from the roof. Take care of those trees, because when a tree dies in the desert all the water that went into it is lost too. 

Our friend Richard Roati has several big fruit trees in his yard. To offset his water use (and water bill) he has two big cisterns that collect water off of his roof. And he has hooked up water from his bathtub and his outside washing machine. All that water supports his citrus trees, carob, and jujubees. He has also started a nursery of native plants (including agave and cactus) that he has rescued in his neighborhood. We actually got our three jujube trees from him! Thanks, Richard! 

It's important to plant foods that your family will enjoy to prevent food waste and loss of all the water that goes into it. If you already have some fruit trees in your yard that you aren't gleaning, you can always call our local treasure Iskashitaa Refugee Network to come harvest them and prevent food waste. 

In conclusion, here are some recommended ways to put in your Desert Food Forest. 

1) Plant edible native trees and plants with rainwater harvesting (mulch covered) catchment basins. 

2) Plant low-water heritage fruit trees in basins with greywater from your washing machine, air conditioner and/or bathtub. Supplement that with rainwater from your roof directed to cisterns (water barrels). 

3) Plant durable, drought tolerant fruit trees in basins with water directed from your roof supplemented with some rainwater collected in cisterns (large rain barrels.) 

4) Plant a few of your favorite fruit trees that you can maintain with roof and greywater (maybe supplemented with very little city water.) 

To be really sustainable, it is important to calculate how much water you get off of your roof and various greywater sources and then plant only what you can maintain on that budget. 

Watershed Management Group has a calculator you can use:

https://watershedmg.org/water-budget-calculator

Like our friend Richard (pictured above) we do a combination of these four approaches in our edible desert forest.  

You can read more with Richard Roati in Exploring food forests in Tucson by Elena Acoba.

Check out the Mayor's Million Trees program. 

Velvet Mesquite - Arizona Tree Profiles: https://youtu.be/zi47emImvFw

Being Neighborly (or Crazy Weed Lady Strikes Again)

Neighbors walking their dog by my moringas

Dan and I are blessed to have good relationships with our neighbors. One reason is because I chat with them when I am out tending my yard. As anyone who walks down my street knows, I love to talk about our "edible food forest." Our neighbors know all about the edible weeds in our yard and how our native trees and moringa are flourishing in our rainwater harvesting catchment basin. One neighbor gamely tried purslane and then planted it in her own yard! 

In a previous blog, I shared how Dave allowed Dan to install gutters and a downspout on the overhang so we could collect the rainwater in our cistern. The overwhelming response on Facebook was, "Good neighbors!" And Dave is a good neighbor. But it was also mutually beneficial. Directing that water into the cistern prevented unwanted erosion in his yard. 

On the other side of the house, our neighbors leave their kitchen scraps for our compost pile. Again, mutually beneficial because it doesn't stink up their trashcans and occasionally they get some of what we grow in the garden. And other food items are distributed over the wall as well... veggies from a big haul at Produce on Wheels, soup (made from food scrap broth), even desserts!  

In the other blog I shared how I will pull the weeds in my neighbor's yard (especially nasty goat heads.)  After the big storm that filled the neighbor's yard with palm fronds, I picked up some and cut them into mulch for our yard. You see, our woodchip mulch has broken down over time and become a part of the soil. So last year I cut our horse purslane into mulch. (It looks like straw...) I decided to take advantage of the palm fronds until the horse purslane grows back and makes living mulch. I wouldn't really recommend it. For the amount of mulch, it really wasn't worth the effort.  

You can see the horse purslane starting to grow back in the picture below and some of my makeshift palm frond mulch. 

While I was in my neighbor's yard I spotted a bunch of palo verde sprouts. To them, they were weeds. To me they were yummy sprouts.  So I picked them and washed them to eat. Again, mutually beneficial!  I even convinced the gals to try them.  They liked them so well, that we split the bounty! How cool is that?! 

Picking the palo verde pods led to the easement where I found my favorite edible weed, purslane, and Dan's favorite, amaranth!  Dan and I gathered a bunch.

That's our dog Pooh, not Dan. This is an old photo.

We gleaned enough for Saturday and Sunday brunch. Saturday we had amaranth scramble with eggs and potatoes. And Sunday we had sautéed amaranth and mushrooms. YUM! FYI Amaranth tastes a lot like spinach (only it's healthier!) 

While I was out watering my yard, I noticed that the bermuda grass in Dave's yard was growing like crazy from all that rain.  So I decided to give it a trim and maybe use it in my compost pit. 

While I was at it, I pulled some sticker weeds. 

I pulled some grass out by the roots and gave some a trim and collected it all for the compost pile.

I should have gotten to it sooner, because some of it had gone to seed. Live and learn...

So I spent an hour going through it and taking out the seeds before putting the grass in the compost pit. (I was curious how much seed was in there, but I won't be doing that again.) O.K. I admit it. It was a waste of time.  But while I was out there I had a nice conversation with the neighbor across the way about not using RoundUp. While we were talking another neighbor came up and told me that she has stopped using RoundUp out of respect for me. 

You can see why Dan calls me the "Crazy Weed Lady." lol  I don't know if that title has caught on with the other neighbors.  But they don't seem to mind my ramblings too much.  I recently found these two gifts at my front door. Aren't neighbors great! 

UPDATE on Spring Garden in Desert Food Forest

In my April 6th blog I wrote about my little experiments of growing a vegetable garden amongst my desert plants at strategic spots around the front yard.  Here are the results of those experiments and what I learned from them. 

I planted one of the tomato plants in a hole left from pulling out a dead milkweed. The soil around the roots looked really good so I thought the tomato would do well out there in the sun. I protected it from lizards and squirrels with a plant cage.  As you can see, this tomato plant did great. I was delighted when it got flowers. But I wasn't sure if it was a self-pollinating tomato, so I took the cage off of it for a few days.  

To be honest the plant cage was a little bit of a pain. I had to remove the gravel I had built up around the cage to keep out the pesky lizards. And it was difficult getting the spike that held the cage down back into the hard ground. One day I spotted some termites in the woodchip mulch dangerously close to the tomato plant, so I had to remove the cage to pull the mulch back. Another time I had to remove it to pull off some low branches that were getting brown from touching the ground. But all in all I'd say it was worth it. Look at all those tomatoes that the squirrels can't get! 

opening the cage

The next experiment wasn't as successful. I wanted to see how our tomato plant would do in the mesquite guild. I was hoping the tomato plant would benefit from the nitrogen the bean tree fixed in the ground. I don't know if there was too much shade, mulch or the hard ground that kept the plant from thriving, because I damaged the trunk when I pulled off a low hanging leaf. 😒

Next are the Jerusalem artichokes (also known as sunchokes). I hand water all of my garden to control how much water I use. I was concerned about how much water I used to get these started.  I watered them several times a day to keep the bulbs moist as recommend.  It was really good for soil. Check out the mushrooms growing there! 

But all the new watering used up the rainwater in my cisterns. Once they were established I cut back the water to once a day.  They seem to be alright with it. I think the living purslane mulch helps retain the water.  I heard that plants don't take in water above 80 degrees. So I try to water them in the morning just after 8 a.m. (Now that it is getting hotter, it's more like 7 a.m.) 

Jerusalem artichokes now hitting the top of the cage 

Unfortunately, I didn't get directions on the sunchokes before planting them. I found out later that they would crowd out any other plant nearby. So when they got bigger, I removed the tomato I planted under the same cage.  I dug the hole in the new spot first, then I carefully dug around the roots of the tomato plant and grabbed some of the surrounding soil to plant with it.  

Might have been better not to do this during the heat of the day... It was looking really sad. I even had to prop up the wilty branches with some sticks.  I thought it might be a goner. 

But I watered it and concocted a shade contraption for it.

I went ahead and harvested some purslane for lunch while the sunchokes were uncovered.  

The tomato plant is thriving on the south facing wall that gets plenty of sun and occasional shade from the toilet planter (don't ask... lol)  I try to water the tomatoes at the same time everyday at 8 a.m. before it gets too hot.  

Well, that was a fun and mostly successful experiment!  I learned a lot and didn't kill most of my plants. 

Horse Purslane Mulch

horse purslane provides living and dry mulch for our yard 

You might remember how our yard transformed into a "glorious habitat for pollinators" after the abundant rain this summer. While some people might call them weeds, we were delighted to have this patch of horse purslane as living mulch to slow down the water (preventing erosion) and allow the water to sink in while nourishing the soil. Our edible forest flourished. Our moringa trees grew crazy big and our jujube produced more fruit than we could eat! 

I pulled out the purslane along our path so it would look intentional.  It's super easy to pull!  

Neighbors complimented us on how lovely our yard looked. 

pile of pulled purslane 

If you pull it before it goes to seed, it makes good compost too - especially if you have a hot compost pile that kills any remaining seeds.  

When the pile started to get brown I broke it up into small pieces to replace the wood chip mulch that was decomposing in our basin. Free mulch! 

The rest of the purslane morphed to burgundy with the season.  

Instead of seeing the beauty in the new shade, I worried what the neighbors might think about it -  especially the purslane that the ants got to. It looked pretty weird without its leaves. So I decided to cut it up into mulch too.

In retrospect, I may have jumped the gun.  I heard that some farmers in Wilcox were using purslane as a cover crop. So I googled, "What does purslane add to the soil?

Purslane grows close to the ground and spreads out to create a thick mat that suppresses other weeds and helps to keep the soil cool and moist. This living mulch can be a great benefit to the garden but also it must be managed.

I guess it would have been better for the soil to leave it in until the roots decomposed into organic matter. After learning that, I waited until the purslane dried up before breaking it into smaller pieces.

Notice the red horse purslane in the foreground and the dried straw-like mulch in the background...

At one Master Gardeners presentation, they mentioned that we don't have a lot of organic matter in our desert soil. Is it any wonder when we dig out all the native plants (weeds), rake up the leaves, and even use Roundup that kills the weeds, the soil, the insects and microbes in it. I hope that one day we learn to value our health and healthy soil above superficial "appearances."

A few years ago, I spent weeks pulling Bermuda grass and invasive Russian Thistle out of the alleyway to make room for edible weeds. I dubbed it my "Alleyway Buffet." So I was happy with the patch of horse purslane that become a habitat for butterflies and other pollinators. I watched in awe as the birds swept down to nosh on the purslane seeds. 

alleyway and the area of our future 3 Sisters Garden

Imagine my shock when I caught a neighbor spraying Roundup in the alleyway behind his house - right across from the children's playground and our 3 Sisters Garden. If he had just waited, it would have dried on it's own in a week or so. I would have been happy to use it as mulch! Instead it's going into the landfill.   

Here I am raking up the poisoned horse purslane (including some in our 3 Sisters Garden where the Roundup had spread when it rained... ) We asked the neighbor if we could spread some gravel that was under our eucalyptus tree behind his yard as a natural weed repellent.

Meanwhile, our front yard basin is covered with a bed of free organic horse purslane mulch. I can't wait to see how it keeps the moisture in the ground when it rains and then breaks up into organic matter for the soil. 

More Information: 

Is Purslane a Friend or Foe of the Garden?

Attack Your Water Bill from All Directions!

by guest blogger Steve Barancik

Can you improve your sustainability? We have! At least when it comes to water.

This is our most recent water bill. As you can see, our water usage has been trending sharply down over the last two years. We're now at about 30% of average residential consumption.

We've managed this drop despite:

• Keeping a garden
• Keeping chickens
• Nurturing a couple fruit trees (while giving the death penalty to a couple others)
• Planting trees and cactus constantly!

It can be done...and you can save money while doing it!

(And remember: lowering your water consumption lowers your sewer bill as well.)

THE STUFF WE'VE DONE

We guttered up part of the roof, where runoff was not being made good use of, and attached the gutters to a tank....

That water now goes toward fruit trees and the garden.

Do we use ollas in that garden?...

Why yes, we do.

We turned off the irrigation to our landscape plants....

You'd be surprised how many of your plants are established and don't need it!

We removed the "weed-control" plastic from both front and back yards....

We used passive water harvesting techniques to:

-redirect (and infiltrate) water where it's needed....

- keep water from jumping the curb and leaving the property....

- and capture water that runs by the property or runs onto the property from neighboring properties!...

We dug a basin and diverted alley runoff to support a mature oak without groundwater....

And by the way, we eat from that oak. So do our chickens!

One key thing we do is make use of our graywater...and here's the thing: We don't HAVE a graywater system; we ARE the system. We capture shower water in buckets....

...and sink water in a dishpan.

(That's Lisa—the other half of "we." She thought of the dishpan as a graywater tool!)

We even catch laundry water in a bucket!...

The tank holds the laundry and spins. The spigot drains the water

Oh, and speaking of buckets...

Why would I go out of my way to get a straight-sided bucket? Well, it certainly makes scooping water out of a flooded street easier! All it takes is a quarter inch rain event for me to be able to fill basins that aren't filling on their own.

I'm a big believer in the water-saving powers of mulch....

I not only try to make use of all the debris and cuttings from plants on my property, but...

I've been known to rescue landfill-bound rakings from neighbors as well!

I even use a technique to irrigate BENEATH my mulch in order to lose less moisture to evaporation.

When it comes to water, I contextualize our use by comparing it with what falls on our 8,257 sq ft lot. At 11.59 in. of rain in a normal year, we have just under 8000 cu. ft. falling on us. Our groundwater use for the last year was only 3300 cu. ft., so I'm pretty happy. I'll be happier still if you're able to put any of these techniques to use yourself!

Another benefit...

This shaded walkway didn’t exist when I moved in six years ago...

Steve is a teacher who thinks his students deserve better than what we're leaving them. You can read more on his facebook page.