Mulch+Trench=better water infiltration.

this attempt was started when I was trying to devise a way to increase water retention through mulching and had many failures while conducting experiments either because the water would wash away while watering the surface or would dry up to quickly, so what I did is I used some concepts from Sepp and Brad lancaster.
To illustrate, I dug a bowl shaped depression in the ground filled it with mulch and observed that I had achieved some positive results, so I then extended this into a mulch filled trench that only needed watering at 6-7 day intervals.
So what I have made is a water retaining trench that forces water infiltration,attracts worms and many other critters that eat up the mulch.
Also this is set on a zone 7 desert garden dependent on my ability to harvest rain water from our roof.
I have also provided a sketch design to show you what I mean.

I'm beginning to think along similar lines, with already planted fruit trees and other permanent plants, currently under drip irrigation. The soil is such a tight clay that after running the irrigation for a few hours the water starts to plume sideways along the topsoil and not stay near the plant. Suspicion led me to drill into the soil with a long drill bit near the emitters and sure enough, only 6-8 inches down the soil was bone dry, even after several hours dripping! So now I have a 2 1/2 inch diameter auger on my heavy electric drill and I'm slowly (back permitting) making a couple of deep holes around each tree, directly under the emitters, and filling these with something durable and fluffy....wood chips at least, or hair, or fabric scraps, etc.....something to keep the hole from caving in. The emitter will gradially fill these holes and water can infiltrate much deeper than before. Later I realized that Brad Lancaster and others describe a similar idea, called "vertical mulching"......

You can use a hose to "drill" holes like you describe. Just point it into the soil.

I read about this hose idea on another thread on here and went right out and tried it. It went through the first few inches of relatively loose topsoil okay, but once it hit the hard dry clay beneath, no way! I think it might work but I would have had to do just like I do with the auger....fill the hole with water, let soak in (which can take two days), drill a few inches, remove the loose soil, and repeat.

In reply to Alder burns comments. At first I thought compacting the bowl depression would hold water longer but found this did not work so well, as far as compacted clay goes I read that to de-compact hard pan was to do a double dig where you loosen the top soil then work on the hard pan with a pick ax or depending on the size, a backhoe.
the winter squash I am using to test this with has so far spread far into the garden and has fruited several hubards so far, another thing Im doing is pouring green manure tea into this trench and am observing closely during this test.

Alder Burns wrote:I'm beginning to think along similar lines, with already planted fruit trees and other permanent plants, currently under drip irrigation. The soil is such a tight clay that after running the irrigation for a few hours the water starts to plume sideways along the topsoil and not stay near the plant. Suspicion led me to drill into the soil with a long drill bit near the emitters and sure enough, only 6-8 inches down the soil was bone dry, even after several hours dripping! So now I have a 2 1/2 inch diameter auger on my heavy electric drill and I'm slowly (back permitting) making a couple of deep holes around each tree, directly under the emitters, and filling these with something durable and fluffy....wood chips at least, or hair, or fabric scraps, etc.....something to keep the hole from caving in. The emitter will gradially fill these holes and water can infiltrate much deeper than before. Later I realized that Brad Lancaster and others describe a similar idea, called "vertical mulching"......

can your clay be compared to a block of forming clay as far as tight goes?

I would think it might be comparable. Adobe was a popular building material during colonial times in this area. There is a significant amount of rocks, which interfere with both the hose and auger methods.... I do know that in most places in the yard, a hole dug down into the subsoil (say a foot deep or so) can often take two days to soak in when filled with water, which is a sign that the clay is tight enough to cause drainage issues with sensitive plants.....in this light, I planted the most sensitive plants (pistachios, pomegranate, apricot, nectarine, citrus) on raised mounds. I think I need to do this with the figs and persimmons too as these seem to be languishing.....

Reminds me I should do some swales in my garden. Laden with mulch they will help retain moisture in my excessively drained sand.
Curious how the same technique can be beneficial in conditions at opposite ends of the spectrum.

Peter Ellis wrote:Reminds me I should do some swales in my garden. Laden with mulch they will help retain moisture in my excessively drained sand.
Curious how the same technique can be beneficial in conditions at opposite ends of the spectrum.

Its kinda like a cross of swale and infiltration basin since there's no slope in the garden. the first time I did this successfully there have been worms eating up the mulch and making handfulls of fine grity soluble matter for the plants so take up.

I have been working on incorporating small swales into my landscape but there are some issues with doing it.

The biggest one is that the swales now present an ankle-twister if someone were to step into them by accident. After stumbling myself, I had to do something about it. Instead of trying to figure out fencing or signage, I used what I had on hand which is woodchips. I filled the swales up just below the top and let it settle over a few weeks. I had to top off a few areas here or there but it is sufficiently filled to the point that stepping on it won't cause a person to stumble. I have not had a rain event to test capacity but I have introduced water from some holding barrels and it seems to be doing its job sufficiently.

I'm thinking of adding some mycelium and perhaps turning these spots into harvestable organic trenches in the future.

I live in a remote part of Australia where access to external inputs such as free woodchips, mulch, or compost is virtually nonexistent. Living on less than AU$20,000 (approximately US$13,000) a year, we’ve had to adopt a highly resourceful and adaptive approach to our permaculture design and daily living. This budget doesn’t allow for idealistic or high-cost solutions—it demands creativity, careful observation, and a commitment to working with what is already present on the land.

Our climate is extreme and variable—marked by prolonged droughts followed by intense flooding. Summers can reach highs of 45°C (113°F), while winters dip to -10°C (14°F). These drought–flood cycles can persist for many years—sometimes an entire decade. The soil is shallow, with less than half a metre of rocky basalt overlaying a dense clay base. Not the kind of environment most would associate with fertile food forests.

When we purchased the property during the height of a ten-year drought, we invested in an excavator for AU$1,000 (about US$650) per day to dig swales along the contour lines. At the time, there was barely any rain to capture, and the fruit trees we planted quickly died in the scorching summer heat—despite daily bucket watering.

Instead of fighting the land, I began working with it. I allowed the “weeds” to grow—hardy pioneers like native acacias and eucalypts that required no input and no encouragement. Over time, I transplanted similar species from other parts of the property. These resilient trees became the backbone of the system.

When the rains finally returned, I chopped and dropped these hardy trees into the swales. This transformed the swales into what I call hugelswales—a hybrid of traditional swales and hugelkultur beds. Into this growing system we introduced our livestock—sheep, geese, Muscovies, ducks, chickens, horses, and cattle—by fencing them into temporary enclosures along the swales. Their manure became a key source of fertility in this evolving system.

We also began cultivating edible fungi in the hugelswales: oyster mushrooms (Pleurotus ostreatus) and red wine caps (Stropharia rugosoannulata). These not only contributed to yields but also helped break down woody material and enrich the soil with fungal networks.

I adopted Mark Shepard’s S.T.U.N. method—Sheer Total Utter Neglect—to establish a diverse range of fruit and nut trees. I planted widely from seed and cutting, with zero pampering. If a tree couldn’t survive, I chopped it and added it to the hugelswale as biomass. What endured was strong, well-adapted, and ultimately productive.

Our greywater is gravity-fed into the main kitchen garden swales, keeping them hydrated year-round. In winter, after leaf fall, livestock are rotated through the orchard swales. They graze the understory and fertilise the soil, essentially performing all the maintenance.

Each year brings abundance—though what thrives varies with the seasons. In hot years, it’s figs and pistachios; in wetter or cooler years, blueberries and walnuts do better. Not everything produces every year, and that’s okay. The diversity of planting ensures that something always does. I've also included marginal or climate-extreme species, so I'm content with whatever nature offers.

The only real inputs now are time, observation, and pruning. Plants showing signs of disease or chronic stress are culled and returned to the system as mulch. In this way, every plant contributes—either by producing food or by feeding the soil.

Filling swales with biomass prevents erosion, improves water retention and accelerates soil formation. Many of the trees we used are considered “invasive,” but I don’t view them that way. If a plant can thrive in these conditions without assistance, that’s a sign of ecological value. These plants improve the soil, provide shade and organic matter, and eventually become food for future crops. Letting so-called weeds grow is a strategy, not a compromise. They’re early successional allies in the regeneration of land and soil.

There are certainly faster ways to build abundance—especially with access to commercial compost, mulch deliveries, and expensive tools. If I had an unlimited budget, I might have gone that route. But permaculture isn’t about building a perfect system with endless resources. It’s about designing with what’s available.

Humans have grown food using only what they could carry or forage for thousands of years. That legacy of resilience and ingenuity is still relevant today. The modern narrative often suggests that self-sufficiency is expensive, but I believe otherwise. With patience, observation, and the willingness to let nature lead, you can build systems that are not just sustainable—but abundant and regenerative.

P Oscar wrote:Instead of fighting the land, I began working with it. I allowed the “weeds” to grow—hardy pioneers like native acacias and eucalypts that required no input and no encouragement. Over time, I transplanted similar species from other parts of the property. These resilient trees became the backbone of the system.

When the rains finally returned, I chopped and dropped these hardy trees into the swales. This transformed the swales into what I call hugelswales—a hybrid of traditional swales and hugelkultur beds. Into this growing system we introduced our livestock—sheep, geese, Muscovies, ducks, chickens, horses, and cattle—by fencing them into temporary enclosures along the swales. Their manure became a key source of fertility in this evolving system.

We also began cultivating edible fungi in the hugelswales: oyster mushrooms (Pleurotus ostreatus) and red wine caps (Stropharia rugosoannulata). These not only contributed to yields but also helped break down woody material and enrich the soil with fungal networks.

I adopted Mark Shepard’s S.T.U.N. method—Sheer Total Utter Neglect—to establish a diverse range of fruit and nut trees. I planted widely from seed and cutting, with zero pampering. If a tree couldn’t survive, I chopped it and added it to the hugelswale as biomass. What endured was strong, well-adapted, and ultimately productive.

Our greywater is gravity-fed into the main kitchen garden swales, keeping them hydrated year-round. In winter, after leaf fall, livestock are rotated through the orchard swales. They graze the understory and fertilise the soil, essentially performing all the maintenance. ...

Filling swales with biomass prevents erosion, improves water retention and accelerates soil formation. Many of the trees we used are considered “invasive,” but I don’t view them that way. If a plant can thrive in these conditions without assistance, that’s a sign of ecological value. These plants improve the soil, provide shade and organic matter, and eventually become food for future crops. Letting so-called weeds grow is a strategy, not a compromise. They’re early successional allies in the regeneration of land and soil.

Thank you for sharing how you turned problem weeds into a solution.  A beautiful permaculture story ...