Mulching in drylands

Wondering about the effectiveness of mulching in arid and semiarid drylands, poor and sandy soil with lots of sun and wind. When rains have been missing for a while, call it drought, then they might come back with few and occasional showers. I've observed the rain can't actually reach the soil as it falls on the mulch surface  and stays there. Then evaporation comes and plants do not receive any water from the roots. I know of the enormous beneficial effects in terms of soil temperature mitigation, weed control, on site fertility and soil biology enhancing.
Just asking what is your experience, maybe you have experimented techniques to welcome the first light rains in a better way.

I live in Northern California, and have a lot of clay in my soil, so I'm not sure I  Qualify.  I put wood chips in a space that basically just grew weeds, and all of those would die in the summer. The ground would become so hard you couldn't dig it, and it would even crack.  After a put 8" to 12" of wood chips down it made a huge difference.  I could pull the wood chips back several days after I watered and the ground would be damp.  (I have to water because we don't get any rain in the summer at all.  I can't remember the last time it rained.).
I'm  certainly not an expert on this subject, but I think mulching even in the drylands is totally worth while.  I would think at least some rain water will make it to the soil, and it will last longer than if it wasn't there.  Also over time the wood chips will improve the soil so it will hold the water longer than the sandy soil.  The frustrating part is I believe all the amazing benefits of wood chips takes so much longer in the heat and dry weather.  We still get the benefits, we just have to be more patient.
You could experiment.  Maybe put something like paper, or paper towels on the ground. Put a bunch of wood chips on top.  After the rain check it out.  Then you would know for sure if the rain is getting to the soil, or evaporating before it gets to the soil.  Good luck to you.

Following to see what replies you receive, as my future land is in an area that is quite dry - bordering on cold semi-arid.

Apart from using sunken beds, soaking the soil and then each layer or mulch as it's applied, and maybe sloping the mulch surface to make the rain run into an area it can reach the soil, I don't know.

In my previous garden in a hot semi-arid area I mulched heavily but had access to plenty of water so I watered daily using soaker hoses under the mulch --the type made from recycled tyres that slowly leak water.  My future land will be more dependent on rainfall so I need other solutions.

I like your thought of testing mulch out first, Jen!

There's a lot of information in this thread: https://permies.com/t/58559/permaculture-projects/Big-Fat-Thread-Dryland-Farming
Not specifically mulch, but lots of suggestions for techniques that can help in areas of limited rainfall.

Marco said, " I've observed the rain can't actually reach the soil as it falls on the mulch surface  and stays there.

It depends on what you are using for mulch.

Like Jen said with wood chips she pulled them back and the soil was damp.

I used large rock thinking I was smothering a weed only to find the ground damp underneath the rock.

I had sweet alyssum that I chopped and dropped that the soil stayed damp underneath.

These basically are the only things I have experience with in my drought-prone area.

I have been using about 6" of sycamore leaves around the plum, apricot, almond trees and pomegranite. For the veggie garden and berries, I use wood chips from the oak tree that fell into the road and the forest service chipped it. I'm on the last bag of it in the second year. Deep watering stakes get the irrigation water under the mulch for the trees. The veggies get soaked by a hose about once a week which helps the daily drip irrigation.

I'm also in northern California where we've basically had no rain since March and wildfires are an ongoing threat. I have semi-raised beds for the veggies - the bottom half is dug into the ground - I didn't want to fully raise them because it gets so hot in the dry season, but didn't want pits because it can rain a huge amount during the winter.  I covered the bottoms with 1/4" hardware cloth to deter voles. (Also have mesh attached to the outside of the beds sticking up 18" high to deter our young cats that were supposed to catch the voles but prefer to play in garden dirt instead!) I was able to put in a cover crop of a legume mix last fall and chopped that in, along with any green plants I was pulling up from other places, including a ton of mustard that has sown itself all around our property.

I was afraid of using wood or other types of flammable mulch because of the fire danger, but decided that if a fire came that close, I'd have other worries... The grass here gets pretty tall by spring, then dries out to a hay/straw mix, so am using that over the soil (anywhere between 2 and 4 inches deep) and I have drip tape underneath. I used chopped greens and biochar (at least that's what I'm calling well rinsed charcoal from old burn piles) in alternating layers with garden soil to get the microbiology going in the soil, along with a little rock phosphate. The plants look so much better than last year, despite our having around 100-degree temps for the last 2 1/2 months - I found peppers, eggplant and okra don't like it that hot and neither do squash and beans so rigged shade cloth over those, but might need to add a misting system if it happens again next year. Pretty much all the plants went into dormancy during that time but at least they stayed alive and are now taking off with the temps more in the 80s. I believe smoke from fires has also caused delays.

I planted ten fruit and nut trees in spring 2020 and 6 additional ones this year. Dug a vertical mulch trench around several of them about a foot wide and two feet deep a few feet away from each trunk, filled with pine needles and dry grass, to hopefully hold precipitation in the soil longer into the dry season. Mulch on top of the soil around the trees has been mostly twigs from ponderosa pine as I read somewhere that trees do better with fungal networks and that a twig mulch stimulates development of those. Had an amazing haul of fruit from a nectaplum, nectarine and apricot already this year (about 70 fruit on each tree) and a few apples - although with the heat all the fruit trees went dormant with green fruit just hanging there and ripening about two months late. Been watering them by hand about once a week - hoping to get drip in before the season ends... (By the way, not everything has lived - lost an olive, three chestnut trees, one hazelnut, an avocado and an apricot due to a variety of problems - growing in a new-to-me location along with climate change is definitely a learning curve.)

Thanks for explaining your techniques when you have water access.
Waiting for further interventions, I just share my understanding of drylands farming:
Water retention
Rainwater harvesting earthworks: swales, stone lines, dams, diversion drains, smile berms, roadside runoff harvesting, etc..
Organic matter in the soil
Mulching, cover corps
Crust disruption: initial deep digging, taprooted plants

Create the succession: start small by planting only drought-resistant, local, fast growing, pioneers, nitrogen fixing grasses and trees to create the conditions for future planting of more demanding crops (vegetables and other fruit trees):
Developing a canopy that provides shade and humidity for crops to grow protected. It could be substituted later on by nuts, timber or big fruit trees (shade, humidity and biodiversity);
Water retention and soil building through root systems, beneficial microorganism and biomass production;
Chop and drop (cutting the grass at the base and the branches of the trees) through the whole process after the first years growing in height (prune the lateral branches of the pioneer trees to make the tip grow high faster).
Evolution in a forest: stability, resilience and high diversity

When planting trees:
Dig deep holes, keeping aside the topsoil
Incorporate from the bottom lots of organic matter, manure, charcoal dust, kitchen waste, chopped aloe leaves, etc..
Put back topsoil
Plant the tree in a sunken bed
Mulching
Watering

FARMING TECHNIQUES:
Build sunken beds, using the "zai pits" / "Deep Soil Farming" techniques with lots of organic matter, and keep raised paths.
Value the species that do well, but still maintain the diversity. Plant densely.
Keep the beds permanent!
Outside the vegetable garden beds (on the grass lines of the syntropic agroforestry system or under a fruit tree orchard) keep weeds as living mulch/cover crop, slash periodically and use them as mulch; otherwise, seed nitrogen fixing legume crops or local grasses and do the same.
Plant windbreaks around and within the shamba https://treeyopermacultureedu.com/chapter-6-trees/windbreaks/

FMNR (Farmer management natural regeneration)
Select species and stumps: for each stump, choose a number (2-5 depending if it is a shrub, low tree or tall tree) of the strongest, tallest and straightest stems to leave.
Prune and manage: remove unwanted stems and tree branches, protecting the remaining from livestock.
Smile berms: dig a flat surface around the base of the tree, placing the soil downslope creating a berm that retains water and fertility.
Cover the soil: use the prunings for mulching or sow local grasses in the basin with the tree at the centre.
Maintain and utilise: return to the trees and keep removing new stems and side branches; enjoy firewood, fodder and mulch productions.

Thanks for share your adventure, I get some inspiration.
Though, my concern was specifically about mulching in drylands with no irrigation and low scarce precipitation.
I'm in East Africa, very very small inputs available.

Agree,stones could be just used in emergency in very slopy areas cause the heat retention also.
Will check that plant for living mulch, though during drought there is no planting happening.
But yes, prepare for the rain!!

I've had similar concerns but have experimented enough to know that yes mulch works. I'm In a part of Canada which is supposed to receive 16 inches of rain a year but for the last few years have gotten about half that.

The mulched areas definitely hold moisture for much longer through the heat and wind. But yes if there is a light rain it does not reach the soil at all and I count it as nothing.

One technique I am incorporating into my planting is placing a rock beside each tree or plant in the mulch as the rock collects dew every night and is always damp underneath.

Very fascinating and caring application. Will try it out for sure!! I have read here in permies it is good to mulch the rock itself to avoid excessive heating from the sunlight.

I don't live in drylands, but we have had a drought all summer. Maybe it's broken now, but we're still way behind. It rained .85 inches the other day. I had just pulled my garlic and was weeding after that rain. There's 3-4 inches of wood chips, and the earth underneath was basically dry. I'm not sure how much rain it would take to soak through the chips and wet the ground, but it's more than an inch. I have to assume if I had a thick mulch, it would take even more. In my case, I'm expecting 2-3 feet of snow-melt to charge the soil with water in the spring, but if you don't get that, I could see it being a problem.

This is a great practical feedback based on your experience, thank you for that!
A user shared a delicate technique: place a stone close to the base of each plant to create a sort of a space to allow water to reach the soil.. and another recommend to mulch on top of the stone to avoid overheating.
Good luck with the art of gardening!

I’m in southern Oregon and just purchased property that is mostly clay. I’ve found when the ground is moist(not saturated, wet clay is IMPOSSIBLE), if I scrape the top layer a couple inches and then lay down woodchips mixed with newspaper that’s been through the chipper, water, lay whole newspapers over the spot, the moisture retention was surprisingly good. Compared to the areas that are just chips or just newspaper.
Sloooowwwwly building soil.  

I understand your point where minimal rain may not soak through the wood chips, but would minimal rain be enough to grow your plants without wood chips if the ground dried out the next day?  The wood chips will help retain the moisture in the ground but as you found there needs to be enough moisture to begin with or you will never overcome the dry times.
You might consider some type of water catchment, similar to what they use for guzzlers in the desert.  A sloped roof or a waterproof tarp on the ground sloped so the runoff is directed where you need it.  If you make something 4'x8' you will be collecting water from 32 square feet and directing it towards your plants.  Make a larger catchment if possible and you can greatly multiply the amount of water to each plant.  If you can direct the water into some sort of holding tank you can run drip irrigation to all your plants and the water will slowly soak into the ground over several days after a rain and the wood chips will help to retain the water longer.
https://images.squarespace-cdn.com/content/58a39aa7db29d6f758c081e1/1494025182086-TO2XN1M4J2VRG45TB27Z/SP-AZ-DTGuzzler-3.jpg?content-type=image%2Fjpeg

It is going to matter the types of mulch and types of soil.  I am in a heavy clay soil.  Without organic in the soil it seals off and is basically waterproof.  So water normally runs off doing nothing for the ground.  If I want it to get wet I need to hold soil moisture hold the moisture against it for a long time and ideally provide a path into the soil for the moisture to follow.  So the ideal would be a large surface mulch like a board that is sloped so the moisture runs off it.  The ground is sloped so the concentrated moisture runs back under the board and is trapped.  Between those 2 layers I want a solid mulch layer.  The goal being to provide nutrients for an plants that grow creating organic paths into the soil and food for worms improving the soils ability to absorb moisture.  In a pure dryland mode with no irrigation I probably need 100 square feet of area concentrating its water on just a few square feet.  For example the water off the roof of the house would maintain a strip of grass about 18 inches wide for about 2/3 of the summer at which point it burned down and went dormant till the water returned.  Now you can keep little tiny strips green by dropping mulch strips across the grass strips holding more moisture in, in selected areas.  The grass on the edges of the mulch will stay green longer.

If you can do something similar thru contour, mulch and rock stacking?  But the reason it works here is that once you get my soil wet it hold moisture extremely well.  In sandy soil that the moisture subbed away that would never work.

If I can add a bit of irrigation to it then the best answer I have found provided it will remain undisturbed is pond scum layer over a grass clipping or sawdust mulch.  The pond scum lets some moisture thru but provides a nearly plastic like barrier to evaporation.   This will allow small shrubs with minimal irrigation.  But the pond scum surface after it is dried is very fragile.  So this only works in areas that are NOT disturbed in any way.  This one also works if I can put it at a low point and let my bare soil do what it does best which is shed moisture.  It runs down hill and under the pond scum layer to soak into the ground and the mulch both.

Yes, moisture is necessary and evaporation without mulch would be sadly excessive.

Got to experiment with these condesners.. with scavenged materials as I'm in East Africa working with really marginalised communities. Thank for the input!

Unfortunately I'm in working with our sandy soil, south coast of equatorial Kenya. No algae here. Still I understand your point of concentrating the water in few spots so it will stand through the evaporation in between rains.

This past year gardening in South San Antonio, Texas, I've learned that deep mulch is the secret to gardening in this climate.  I was away from the garden for a couple weeks while moving back to the country, and when I returned yesterday the plants with deep mulch (at least six inches of plant trimmings, were distinctly happier than those with less mulch. Bananas have grown as high as the roof soffit with only rain from the roof.  They initially had about a foot of mulch, now mostly decomposed.  All the beds have mixed mulch of wood chips, tree trimmings, plant prunings,  and grass clippings.  I'm totally sold on deep mixed mulch (sheet composting) and am going for it in a big way in my garden at home.

Tyler, do you consider yourself to be in a dry land? I think of San Antonio is a much more humid area. I've heard that a lot of mulch in a very dry area will absorb the rain and not let it get to the plants.

San Antonio is just east of a line between moist and semi-arid climates.  It is slightly wetter and more humid than where I live in the Hill Country, which is semi-arid.  Unmulched plants here dry out and die unless adapted to the conditions.  I've had much better success with mulched gardens than unmulched here.

I live in a semi-arid climate in which the soil is often dry from April thru October. During that time, it's impossible to farm without irrigation.  

Traditional farming in this region uses dirt mulches because organic materials such as grass, etc., are used to feed animals, mostly goats and sheep.

I don't have farm animals and use all the organic material for mulching and/or composting. Well, you could say that mulching is "surface composting", as opposed to "heap composting."

I have very little water for irrigation. Without mulch, I could only irrigate about one tenth of the surface I cultivate at present.

Using organic mulches is not as effective as using dirt mulches in preventing evaporation; however, dirt mulches require more water then I have because one has to flood one's field in rows dug between the plants. Dirt mulches are also very work-intensive because you need to hoe the soil after irrigation. To work hoeing under the burning sun day in day out is more than I can manage.

The soil dries out via capillaries that form in clay soil. First the upper soil dries out and then the humidity in lower layers reaches the surface via the capillaries to evaporate at the surface. Once these capillaries are formed, the soil dries out very rapidly.  The soil dries out faster than you can irrigate.

Organic mulches prevent evaporation at the surface to a degree; however, after irrigating by sprinkler or hose for three months, the soil tends to compact and capillaries form all the same. The organic mulch obviously makes it impossible to hoe the soil. That's why irrigation with organic mulches becomes harder towards the end of the dry season. When it gets really bad, you can only harvest a plot and then loosen the soil before planting a new crop. It's remarkable how irrigation is a lot easier after that.

I'm in Wyoming. High, dry, arid, WINDY!

I've used a variety of mulches. I'm currently using pine shavings which are sold as animal bedding. This is mostly because I do not have a truck and no one will deliver to me.  I do find that light rains do not penetrate the mulch. They did penetrate hay mulch but like I said, access problem for me so shavings it is. Also, hay blew off but the shavings don't.  This is the first year I've used shavings as my mulch and I've never grown such wonderful plants before. Weeds are easy to pick out and yeah, all in all my mulch experience has been great this year!

Marco Bonfanti wrote:Wondering about the effectiveness of mulching in arid and semiarid drylands, poor and sandy soil with lots of sun and wind. When rains have been missing for a while, call it drought, then they might come back with few and occasional showers. I've observed the rain can't actually reach the soil as it falls on the mulch surface  and stays there. Then evaporation comes and plants do not receive any water from the roots. I know of the enormous beneficial effects in terms of soil temperature mitigation, weed control, on site fertility and soil biology enhancing.
Just asking what is your experience, maybe you have experimented techniques to welcome the first light rains in a better way.

I already replied above in a general way. Let me come back to the specific point your raised.

I also at times wondered whether the mulch didn't prevent the rain or irrigation water from reaching the soil because light rain and moderate irrigation didn't seem to wet dried out soil.

I think the reality is more complex. As somebody already pointed out, if your soil is completely dried out, a little rain won't be enough to wet it sufficiently, with or without mulch.

So, the problem isn't the mulch. The problem is that the soil is completely dried out and that a little water will just disappear. If the soil is compacted, it may run off. If it's not compacted, it'll will percolate to deeper layers. You won't get sufficient humidity in the top layer until the soil has soaked up enough water to reach a certain degree of humidity in the different soil layers.

The other problem is evaporation via the capillaries that form in clay soil. Once these capillaries are formed, rain or irrigation water will evaporate via the capillaries. The only way to change that is to loosen the top soil so as to cut the capillaries. After that, it'll be a lot easier to keep the soil humid. But that usually requires removing the mulch, which you would probably do anyways when planting new crops.

Edit: As an afterthought, I think the greatest drawback of mulching really is that after about 3 months of irrigation, clay soil will compact and capillaries will form. Irrigation water will evaporate rapidly via the capillaries making it hard to keep the soil wet. I have been thinking long and hard about how to remedy that, but aside from removing the mulch for hoeing and replanting, there doesn't seem to be much one can do.

I have always had problems with birds ripping the mulch apart, which will expose the soil to the sun and to evaporation. Therefore, I always keep a spare heap of mulch to fill in the gaps. This year, however, I noticed that the birds actually had a positive effect in that they loosened the top soil and mixed the mulch with the soil, thus preventing evaporation via the capillaries. As long a the plants are big enough to shade the soil, it doesn't matter if the soil is exposed a bit here or there.

The other annoyance I have are voles. Wherever I dig my hand into the soil, I come onto tunnels dug by voles. All vegetable plots are closely crisscrossed by vole tunnels because the voles prefer my soft irrigated garden soil to the clay soil on the remaining land that's as hard as concrete. While the plants are young, the voles kill off some plants by laying bare their roots; however, once the plants are big enough, the tunnels between the top and bottom layers may actually prevent the bottom soil layers from drying out.

I get a decent amount of precipitation in the year, but most of it comes during early spring, late fall, and in winter as snow - so when nothing is growing. I generally have two to four months (most of the growing season) where there is either no rain, or the rain comes in such small amounts that it doesn't even wet the whole surface of the soil.

I use mulch as a way to conserve the moisture from snowmelt and early spring rain. I don't water my gardens, so I have to keep that moisture in the soil. Unmulched gardens do terribly here, unless they're being watered. Even then, the summers are hot enough that you need something down to keep the soil cool.

I mulch with all kinds of organic matter - wood chips, grass clippings, leaves, small tree branches, etc. I can't mulch with rocks cause the plants would fry. A lot of my gardens are raised, with a rock border. I have to be careful what I plant along the edges because most things can't handle the heat off the rocks. I've had squash vines burn through where they drape over the edge of the bed.

Reading the other posts here I would add that I have a thin layer of wood mulch on the garden. Watering with the hose gets past it. I check the soil to see if it's moist at all. The leaves on the almond trees are drooping a little. I'm going to rake away the leaves, loosen the soil with a 6' pry bar and water with a hose. Things like that need to be done at the end of the dry season one time. We had a thunderstorm but the ground was back to dust a few hours later. Lucky the artesian spring is still flowing.

I often have a few rocks anchoring shade cloth, or the upside-down tomato cages in my raised beds lined with weed barrier cloth. Heat over 95F (here, often over 100 this summer) makes rock's heat even more dangerous, so I realized years ago that some mulch over the rocks was good. Some of the writers in this thread may be applying more water to their veggies than needed--unless the soil is sandy with inadequate amendments? The surface should dry a little; ideally roots will grow below this and be better protected.

A vertical trough around fruit trees, filled with mulch and compost, might dry out too quickly and put roots at risk. Don't forget that a balanced SOIL is a natural goodness, is water-retentive, and a source of nutients.

Wood chip mulch--useful for allowing water infiltration, but usually more nutrient-poor than grass or weed mulch.

I'm in a windy, arid, hot environment. Nevada mountains, about ~6" of annual rainfall.

First, rain catchment is real and is the ticket out of water shortages for many people. My modest solar array, with 6" of rain, is several hundred gallons a year. Building something more specific will do you even better.

Second, I use wood chips for mulch. It actually helps a lot in pretty short order. We have a lot of cardboard, so one thing that works for us is to take cardboard with no plastic tape and put it down over the wood chips, anchored with rocks.

I'm in eastern Colorado, USA, Köppen BSk. We've planted 200+ trees and shrubs in the last 2 years. Two of the three areas are drip irrigated, but the newest area of 70 is not. I water once per week, about 2 gallons per plant, dumped at the base of the plant all at once in very sandy soil. It is a hard life here, with hot, windy summers and cold, dry winters. We have had about a 15-20% mortality rate. If they can't survive on that amount of water, they can't live here. They are all tough, supposedly deep rooted plants. Siberian pea shrub, manchurian apricot, elm, honeylocust, golden currant, hackberry, lilac, chokecherry, burr oak, buffaloberry. They all are mulched with wood chips in a small circle around the base. Without at least some irrigation (they say 3 years) and mulch, nothing but Russian thistle, black eyed susans, and native grasses would grow. The summer rains haven't made it here yet, so I've not seen any natural moisture below the mulch this summer.

I have sandy soil and rock (an old river bed flood plain) and we get about 12-15 inches of rain per year so I'm planning on 9. Very little water between April and September, all our moisture comes in the winter. 100+ degree (f) temperatures in the summer and high UV.

A few years ago I covered a good bit of the yard with wood chip mulch, and that continues. The park strips along the street (some people call them hell strips) do not get watered at all, where I grow tomatoes, pumpkins, and watermelon as well as several dryland ornamentals. This year I tried sorghum as well, and it thrived. Greens do well in the spring but seed and die back as soon as the heat starts. Garlic loves it.

When I started this project I pulled out the grass, mounded the woodchips as deep as I could get them, and watered five minutes every week. That turned out to be too much for some of the plants so I pulled back to once a month. Since then I haven't watered this area at all, other than 2 gallons of water per plant when I put them in the ground.

This year I scattered watermelon seeds rather than planting transplants and got extremely low germination in the spring. However, when we got a rainstorm early September the water overflowed the gutters and now I have watermelon seedlings everywhere. They're thriving and several already have blossoms, although they probably won't have time to mature.

No way this would be possible without mulch. Before I started this project the park strips were watered deeply three or four times per week during the summer and the grass still died, even in the shade. Although the mulch may not gather water with a light rainstorm, I have found that the light rainstorms still increase moisture under the plant canopy. Plants will collect and direct that water down into the soil near their root zones, so if you have plants the moisture still goes where it is needed. Moisture in the mulch layer also seems to prevent evaporation from the soil.

Water runs off of the sidewalks into this area, and I'm using rock mulch along the street edge so any water that comes in off the street can percolate rather than running across and stripping the mulch. The mulch doesn't wash away where there are plants, so I encourage low growing weeds to hold it in place.

Consider also the size and shape of the mulch--large woodchips are going to allow much more penetration than sawdust, for example. Grasses and weeds will allow the water to flow almost straight through, unless there's a lot of matting. Once dry, they don't absorb water easily, while woodchips just suck it up.

More than anything else I am trying to fix the soil so it doesn't need my intervention. Previously that area was dry two feet down even in late spring. NOTHING lived there. Now there's a thriving ecosystem under the mulch.

I live near the continental divide west of Helena MT and it is considered high desert here.
I put down a couple bales of straw in an area and kept it wet for a couple weeks.
That area is now producing pumpkins, squashes, beans, tomatoes and sunflowers.
It is like a mini jungle.
I have to soak it good once a week because of the sun wind and lack of rain, but it has shown me what to do for the other areas I want to plant.

We use the same various techniques here in the central coast CA- very dry less than 3 inches of rain/ yr over the last 2 years, very little cloud cover. We do have city water to our home though. We are on just 3 acres.

Adding mulch even in areas we do not water directly, I believe will help because containment of movement of the water lens underground. If there is any moisture in the soil, it will be contained better, even if it is deeper than the roots of our trees and plants. I know it is there because of the survival of some of our 20-30 yr trees that I do not water - pomegranate, persimmon, walnut, toyon and all the native oaks, etc. I am always looking for ways to get all our grey and black water back outside in the ground into swales praying on their creation of a lens that hopefully builds year after year. Most all our planting is down hill from our home.  

I am always covering any bare ground with  living plants, native and non-native as well as mulching. Every native that I do not need to water, I know is bringing in any moisture from the air whenever possible. I strive for dense woodlands here with breaks I keep more wet. We have been here for 9 years and it has been slow, but I see more and more volunteers coming in each year, more birds, etc.

We moved out for a year after year 6 and had broken lines to an orchard we had swaled. I had mulched it - a lot had broken down and it was weedy. But, these apples, peaches and plums survived at age 6...for that hot 100 degree summer when I could not care for them. So, the frugality with which I had watered them (they grew slowly), did pay off...always such learning from our own experiences very specific to our site.

My failures have been around yield because of not making enough time for getting fertility back ---I know that if I worked harder to get my animal and humanure under this mulch, I would have improved water retention, etc. One day when we are retired and kids are out of the house.

I understand the fear of flammability especially with resinous pine needle mulch... I think the key is in having blocks of areas within drier zones you do water regularly or where you hold water on your land between drier areas. I know there is good literature I have read over the years on fire proofing in permaculture perhaps you have read. I tend to reforest in toyon, valley and coast live oak, ceanothus, sugarbush, lemonade berry, I allow coyote shrub and see a lot of islay cherry coming in under them. Then I have clusters of more water demanding natives  and edible between.

We are definitely not all dialed in here... always on a path and always re-evaluating. Obviously my zone 0-2 are the wettest...but I have "rays" of irrigation from these zones to my outer zones and integrate these with our animals. Trying to move our pigs around to create little pig ponds everywhere ala Sepp Holzer, but much less impressive here due to our increasingly desertified conditions. I have hope. I also watch neighbors land... I see they have old standing sycamores that are surviving without water --we are about 400 ft higher and about 1/2 mile from the nearest creek that runs part of the year above ground.

If you have the muscle for it, find a clayish deposit and bring it to the garden. Excavate the sand about 1/2 meter and put down a layer of clay. Replace the sand and add all the organic matter you can find. Then mulch. Just because you cannot see wet sand under the mulch, does not mean precipitation has been wasted. Indeed if it is absorbent the mulch itself will retain water.
Send all gray water to the garden in mulch basins.