The Water-Harvesting Earthworks: We tend to get the majority of our yearly rainfall in short bursts–and typically only a few of them per year (average annual rainfall is 4.5 inches). Typically, when it does rain, that water runs right off the land, causing erosion on it’s way down to the dry lake bed. In order to grow useful trees and shrubs that will produce food, shade, and create a wind buffer for our permaculture system, we have been turning our land into a sponge to catch and soak up that rainwater when it comes. Doing this can take different forms, but as Brad Lancaster puts it, we try to “slow it, spread it, and sink it” — we slow the water down and pacify it by intercepting it’s straight downhill path, allowing it to spread out and sink in along level contour lines giving moisture to as much of the land as possible. I discussed our permaculture design in great detail in the early posts on this blog, along with maps, charts and photos of the beginning.
In 2013 I got my Permaculture Design Certification and immediately began designing our little 1.25 acre piece of family land, after spending about a year carefully working on the design (and making sure we would cause no harm or disruption downhill from us) we started hand digging our contour swales whenever we had a spare moment. We had had one or two work parties with friends and hosted some amazing volunteers on the land who were excited learn about what we were doing and to help put the system in. I did a lot of digging at night by the light of a headlamp in the summer, when the daytime temperatures were too hot. Our digging here is easy, and the work was extremely enjoyable. It felt creative and saturated with meaning after having visualized every aspect of our design to that level of detail. It was an amazing joy to be moving slowly and steadily towards a beautiful goal… just the kind of soul medicine I was needing.
The Earthworks were mostly completed by 2015 (though we are still making additions and tweaks to the system). It has been a thrill to see them work whenever it rains hard enough to get the water flowing! Although there have been many smaller rain events that allowed us to soak in lots of water in the upper swales, it wasn’t until this fall (October 2018) that we got to see the whole system of earthworks fill to capacity and overflow. Through the early hours of the morning we got 2 1/2 inches of rain and all of the swales filled and overflowed in a pacified, orderly way, while elsewhere in the Joshua Tree area huge erosion gullies were formed, and roads were buried in mud. Going through that experience really underlined the importance of doing this work. Each of those mud flows that buried roads were, at least in major part, a result of the hardscape humans have been creating in this area–rooftops and deeply carved gridlines of hard, compacted roads through the fragile desert that intercept the natural, meandering washes and channel the water into fast, cutting, destructive flows that don’t allow much of the water to soak in and support plants and wildlife. With permaculture design we are working to reshape the already damaged, compacted areas of the landscape back into a sponge, and making use of that increased moisture to grow high-value, desert-hardy (mostly native) food-producing plant species that could become the basis for a truly local and sustainable food culture out here in the Mojave Desert.
Mesquites are the most important food producing trees of our ecosystem that not only provide protein and carbohydrates, but also taste sweet and amazing. We found that the local-native variety of Honey Mesquites were not available in nurseries, so we started harvesting seeds from the ancient-local groves and propagating our own. Drawing inspiration from the Joshua Tree National Park Nursery, we started growing trees in 18 inch deep, tap-root-friendly tubes.
Our little nursery has been an amazing success, supplying almost all of the plants we’ve needed for our project on our shoestring budget. Also, the local-native trees and shrubs we’ve been growing have turned out to be a hot commodity in our community, so we immediately had a little side business growing extras for friends and neighbors. (This fall’s batch of trees sold out in about three days… Clearly there is room to grow on this front if we decide that it makes sense for us in the big picture).
We planted pretty densely along the swales. I’d rather plant more trees now, with the option of thinning the weaker trees out at a later date, rather than risk not having enough density to create good wind buffering and lots of shade for the system. The majority of the trees have done very well and grown rapidly, but a few have been slow and stunted, either by rabbits being able to penetrate inadequate protection or maybe genetics, or from competition from the nearby wild plants… we’re still not sure. The engagement with the land in such a deep way has been rewarding throughout the process. We’ve celebrated every new shoot of green growth and it is SO cool to get to watch the land slowly change! This last summer we picked the first mesquite pods from some of the more advanced young trees. Even though we grew all of our baby mesquites from mama trees that had sweet, delicious pods, we really didn’t know what to expect from their offspring, but so far they’ve been excellent!
Before and After Shots: 2015 and 2018
Notes About our Watering Strategy:
Our ultimate goal is to have an extremely drought-tolerant, shade producing, carbon sequestering food-forest that is almost entirely irrigated by the rain. To this end we’re trying to train the trees to grow deep roots that are positioned to take advantage of the rainwater that our swales soak in. Each tree was planted with a deep water tube that goes several feet down towards below the bottom of the nearby swale– training the roots towards the rainwater source, rather than just hanging out at the surface where the soil dries out quickly in the sun and wind. Our local botanist-hero Robin Kobaly taught us this technique, and we have adapted and hybridized the concept within the context of our design.
What We’ve Planted (and Why) as of December 2018:
In and around the swales:
*Honey Mesquite (Prosopis glandulosa)(Sweet, nutritious pods can be ground up for flour)
*Screwbean Mesquite (Prosopis pubescens)(Same as above)
*Velvet Mesquite (Prosopis velutina)(Same as above)
*Chilean Mesquite (Prosopis chilensis)(a thornless hybrid, common in nurseries)(Same as above)
*Blue Palo Verde (Parkinsonia florida)(Sweet green peas in the pod in late spring, and dried beans in the summer that can be stored year-round)
*Mexican Palo Verde (Parkinsonia aculeata)(Same as above)
*”Museum” Palo Verde (a thornless hybrid)(Same as above)
*Pistachio (Pistacia vera)(surprisingly draught tolerant!)(nuts)
*Jujube (Ziziphus mauritiana)(need to get greywater)(delicious fruit)
*Pomegranite (Punica granatum)( these are better to have in a greywater-fed “oasis zone” situation)(fruit)
*Fourwing Saltbush (Atriplex canescens)(easy, beautiful, edible leaves as a cooked green)
*Quailbrush (Atriplex lentiformis)(same as above)
*Wolfberry (Lycium andersonii)(MY FAVORITE!! sweet and tart red berries)
*Silver Cholla (Cylindropuntia echinocarpa)(yes, this is a FOOD PLANT–the flower buds can be eaten after being de-thorned and boiled)
*Jojoba (Simmondsia chinensis)(not edible, but oil is great for skin)
*Desert Hackberry (Celtis pallida)(growing REALLY slow)(supposedly berries)
*Prickly Pear (genus Opuntia)(amazing, potent, sweet fruit. We love these and are going to plant lots more! Don’t be fooled into thinking they don’t need rabbit protection)
*Bladderpod (Isomeris arborea)(Beutiful plants with flowers and seed pods are edible when cooked or pickled)
In the greywater oasis zones: (more about the greywater system in future posts)
California Fan Palm (Washingtonia filifera)(these will eventually produce delicious tiny date-like berries that make an AMAZING sweet beverage)
Black Siris Tree (Albizia odorotissima)(very fast growing nitrogen fixer–used for shade and eventually as a “chop and drop” support species for the other plants around them)
Black Locust Tree (We have one of these growing and the seed came from a very special permaculture site called Quail Springs Permaculture).
White (Fruited) Mulberry (We were able to get one of these going from a cutting. Very excited to see if we can get both shade and fruit production with it)
Plants on our Wishlist: (hopefully) Coming Soon:
*Lots of olive trees
*Lots more Prickly Pear
My advice for others interested in doing this work:
*Get a Permaculture Design Certification: This is an educational experience that will rock your world and enrich your life in so many ways, empowering you to “be the change you want to see in the world.” We need legions of trained, competent permaculturalists working to heal and re-design every damaged ecosystem on earth. If this work calls to you, come be part of the first Permaculture Design Course ever to take place in Joshua Tree. It will be happening this March at the Harrison House and will be taught by Warren Brush, one of the most inspiring permaculture teachers on the planet! Click Here for more information.
*Do this work in areas that have already been damaged by human activity. Please don’t plow up your wild backyard to put in swales etc. Places where cars or OHVs have driven in the past are perfect candidates. The Mojave Desert vegetation can look very nondescript or even dead for long periods of time, only to burst with life and beauty when the conditions are just right, so don’t be fooled into thinking you need to tear out the humble-looking, but ancient plants on your land to put in more “flashy” species. That would be a tragic mistake!
*Be careful!!! Unless you have done a lot of careful study of your land and permaculture design, and you really understand the micro-watershed you’re land is a part of, hire a trained professional to design/install your earthworks. Water is such a powerful force and will surprise you with its magnificent intensity at times. Please don’t flood yourself out (or even worse, your neighbors) with bad design and implementation!
*Don’t ever skimp on rabbit protection. Trust me, you DO need rabbit protection for all of your baby plants, with very few exceptions. Make fences 3 to 4 times as wide in diameter and twice as high as your initial instincts tell you to. Otherwise, don’t even bother planting. (NOTE: higher elevation residents might need to think about deer protection too).
Thanks for your interest, and stay tuned for more updates about our vegetable-growing adventures, chickens, greywater systems, etc. Please do keep in touch and let me know what you all are up to. Let’s keep experimenting and learning from each other!