The mulch-generating polyculture for Mortal Tree’s PASSIVE garden system is going well. It’s the bed in Foundation for a future I am establishing with bricks.*
The intent for this bed, per A bit blunt method, was to shift the rocks every couple of months to kill off the grass underneath. This worked pretty well for most of the bed. I shifted the bricks in July and made a final small shift about a week ago. Above is the freshly shifted “mulch” around an amorpha.
I also tried covering a small part with grass mulch in May last year, and this took care of any weeds growing through the cracks. Below is the planting now. Like most fun times, there is a mess to clean up afterwards. This bed had a lot of fun last year. What you see is actually mulch I applied, the healthy comfrey, and some amorpha interplanted. I plucked out the little bits of green quackgrass, and look forward to some very lush, beautiful growth here come summer.
I plucked out the quackgrass when I shifted the rocks. Because they block sun and moisture loss, the rocks encourage the quackgrass to grow shallow, allowing me to just pick them up rather than pulling them. What roots did grow deeply are easily pulled because the soil is so soft under the bricks.
This soil conditioning is one if the main perks of using rocks. The soil life is everywhere, with centipedes, worms, spiders -even at this cold season. Soil between the bricks which heaved from the freezing over winter is unbelievably friable. It looks like it has been tilled.
Considering how low this soil is in organic matter, with a clay-coal base, with no amendments like sand or ever even being tilled before, I am very excited to already have such results. The moisture and soil life have brought it so far because I have created the right habitat, covering the soil. The organic matter is starting to accumulate.
Above are some amorpha leaves dropped last fall, which likely have brought in nitrogen the system formerly did not have. The plants were already beginning to nodulate in their pots when I planted them last year. If you would like to learn more about how I ensure they make nitrogen and get off to a good start, I have some notes here on Growing amorpha.
I also harvested some of the comfrey leaves last year, which I left around the plants I harvested from. This is breaking down into gorgeous soil, bringing in carbon the system did not formerly have.
Pictured is some broken down comfrey from a larger patch in the food forest. This new patch should be producing similar soil in the near future. It’s already well on its way.
*This could have been done with some large piece of canvas or the like, or a large piece of plywood. One of my clients decided to try clear plastic just to block water, which was still effective at removing the plants underneath.
I’m not quite sure what it takes to sprout Turkish rocket (Bunias orientalis). Last year I posted a fairly certain observation that a couple weeks in cold temperatures does the trick, only to find in the comments from the ever apt Wooddogs3 that she had sprouted quite a few straight out of the packet in warm weather.
Scratch that idea. I figured something else must have deterred my Turkish rocket sprouts; but then, in later conversation, Heather mentioned that more Turkish rocket sprouted after the pot sat out over winter. (?)
I think the fact of the matter is we are working with fairly wild, unselected seeds. With them, variance is the standard. At the same time, it offers several little known benefits.
Varying the time of germination increases the likelihood at least some of the seeds will sprout in a ‘sweet spot’ of a season, or at least avoid catastrophes, and make it to adulthood. What if an unusually late frost hits or some animal nips off the tender sprouts?
This is a very helpful character for love-in-a-puff vine (Cardiospermum halicacabum) which I’ve grown on a large scale for the last couple years. It’s a warm climate plant, and can’t take frost. I nevertheless plant it in mid April, when we still have a chance of frost. While a few will come up as early as three days after planting and get nipped, the majority of the plants take about two weeks to sprout, and will continuing sprouting up to three months after.
The mechanics that govern this variance can vary, but are usually based on the activity of certain enzymes releasing nutrients necessary to wake up and nourish the embryo that will become the new plant.
Health conscious readers may be familiar with the discussion of improved nutrition in sprouted or soaked grains because the phytates present in these seeds have been removed (see here for more info). This is because in the seed, phytates bind up nutrients -phosporus in particular- keeping them off limits for the embryo (1). Water is one factor that initiates the enzyme phytase, which is responsible for breaking up the phytates (2). In the right temperature range, phytase completes the breakdown of the phytates, releasing the nutrients the embryo needs for growth. In most cases, the need for adequate water and longer durations of certain temperatures ensures the plant can grow to maturity once it sprouts.
Of course, many of our perennial vegetables also need cold, moist temperatures, or dry and warm temperatures, in addition to a later stage of warm moisture to successfully sprout. Phytates are one example of the mechanics generally at work in seeds -enzymes releasing nutrient.* Differences in the genetic makeup can dictate the time each seed takes to activate these enzymes, and release the nutrients for sprouting. Its variance in genetics that often gives such extreme variance in sprouting time, and what conditions are necessary to induce germination.
Most of our garden vegetables were the same way at one time, with lots of variance. They’ve just been selected. If over the next ten years I only saved seed from cardiospermum that sprouted two weeks after planting, this character would soon be the norm.
Although it’s nice to have an idea what’s going on in those drab looking little seeds as they deny us a happy sprout, what can we do to improve the likelihood that we, at some point, actually get a sprout?
Heather had the right idea leaving her Turkish rocket in the pot to see if any more sprouts would show up. Just give the seeds time, and changes in temperature.
I know from experience that keeping a little empty pot of dirt safe for seasons at a time is not easy. As a first step, designate a spot where seeds are protected -by mandate of heaven -or whatever works for you. Tell this to anyone that might come along thinking your untidy plant-keeping needs tossed in the trash.
Rodents seldom care about the mandate of heaven, so cover the seeds with some mesh, or build a hanging tray well above the ground, as Martin Crawford does, to keep them out. I hung some trays in our greenhouse last year which did the trick keeping mice out of squash seeds. The only problem with hanging trays I find is their fluctuating temperature: pots placed on them can easily dry out on a hot day.
Seeds are more likely to stay moist and live if they’re in more temperate climates surrounded by bricks in a shady corner. My favorite spot for sprouting is on the east side of our garage, or on the north side of our greenhouse. I’ll bring the trays from these temperate spots once in a while to the hot greenhouse. For a short time here, I watch them, and keep them watered, while transplanting any sprouts that appear. Once the sprouts stop appearing, I move them back to the less intense climate.
This system is very effective at getting around the errant nature of our prized perennial vegetables and trees. With such complexity, it’s better to just offer a variety of situations to seeds, and wait, rather than trying to guess what’s going on in those drab little seed’s dreams.
*There are even several kinds of phytase. See here for more info.
Blurring gray fur and tails pour like a waterfall onto the floor in front of me. A tense minute, and the place is cleared -bare, clean cement floor, and nothing but hushed scurrying sounds all around. I’d just turned on the light.
This was one summer long ago, when several old building were torn down by the Township very near our chicken house. These were an old garage, another chicken pen near it, and a large old barn. They all housed droves of rats. Where did they go when these building fell? Our place.
We had quite a clean operation. When the rats came, we cleaned it to the max, removed all the wood shavings, straw bales, any and all feed -no matter how tight its container, and even some of the chickens. Despite the cleanup, the invasion lasted for months.
They were too smart to fall for traps. Eerily, one of the traps we found set off with no rat in it, had a freshly gnawed twig from the lilac bush right outside the pen stuck in it, the bait removed. My dad stayed up several nights shooting them with pellet guns. He terminated the lives of hundreds, but only recovered a few because the rats began eating their fallen, dragging them back into their holes immediately, or gnawing into them on the spot. To say nothing of a few unfortunate chickens that fell prey when the lights went out.
The rats made this new house their home in short order -with or without resources. They dug enormous piles of soil out from under the cement flooring, brought in food from some place. We had removed everything else.
When specialists begin throwing out statements about harshly mowing orchards to keep rodent and rabbit from gnawing away bark and roots of trees, I am a bit skeptical. These creatures create habitat for themselves and are part of thriving ecologies. They are eaten by almost everything, providing a vital link in the trophic system. If you have ever studied how these systems work, reducing one part of the chain, reduces, or at least effects, all the others following. If you reduce rodents, you by default reduce potential health of the trees you’re trying to protect.
Rodents feed into a very broad system. Finding examples of what happens when rodents are entirely removed is difficult because we have seldom pulled this off in outdoor settings. If we have come close, someone is also fertilizing and pruning a lot to make up for the loss.
Rodents have many immediate effects too. For one, they dig holes, which allow more air and water to percolate into the soil. This is very good for soil health.
It’s interesting to note the trees most immune to damage by rabbits, voles, etc. are single seeded species, like peach and plum. The species most vulnerable are multi-seeded species, like apple and pear. Rodents and rabbits, every couple of years when the food gets scarce, devour the bark off a couple of these trees, killing the trees. If they didn’t these multiseeded species have a higher chance of sprouting on top of each other, and choking each other out.
Only one successful seed is necessary to replace its parent. Rodents are a factor which ensures the chance any young tree grows to adulthood is very, very low. This is a good thing in natural conditions. It means trees are more likely to be well spaced.
But how do we make our tree “the one” that grows to adulthood when we’ve already taken spacing into account?
The most effective move is just installing tree guards; simple spiral guards are fine for young trees; tree guards like these are better for larger trees. Larger trees are less vulnerable to girdling, but I have seen trunks near five inches in diameter girdled to the hard wood if the snow lays thick enough long enough. For these sizes, I am not a fan of corrugated plastic pipe guards because they’re extremely hard to get on and off, often harming the tree in the process. Even covering the trunks with tinfoil or fine wire mesh is better than nothing.
Opaque tree guards also protect from sun scald: when bright sun reflecting off cold snow heats the cold tree bark, making it crack. This isn’t good. Covering the trunk helps prevent it.
Another tactic is to provide food for the rodents (No, I’m not nuts. Keep reading). The fact is, rodents and rabbits will be present whether you like them or not. If you mow the grass, they will dig tunnels. If you remove food, they will find it, and store it.
I’m not the only one recommending this. One extension service informational pamphlet extolled mowing the grass in an orchard to the finest bits to reduce cover, yet recommended throwing out sunflower seeds when the snow fell. This is intended to divert the eminent population of rabbits, voles, and mice -now forced into starvation.
Apparently the specialists are aware their mowing and trapping are only mildly effective, and that the real issue is diverting and blocking the rodents when times get tough, not killing them. Natural predators do that.
It seems most logical to just leave the tall grass and brush -at least in isolated corners, so the rodents can feed themselves.
There are also biological deterrants, such as Sepp Holzer’s bone tar. Here is a forum discussion on the subject. Sepp Holzer explains making bone tar and its use in his book. I own a copy, and quite like it. I have never gone through the trouble of making bone tar though. Tree guards have done the job for me.
There is an idea that planting certain bulbs and other plants around a tree deter rodents and rabbits -especially voles, which eat roots underground. In controlled studies, ground covers like Pachysandra species, and bulbs like daffodils are themselves very unpalatable to rodents. This doesn’t necessarily deter their cozying up to your trees.
I’ve had trees with no guard brutally stripped by rabbits, despite a ring of daffodils around it. Keep in mind, when hunger gnaws, rodents gnaw just about anything -tasty or not. While these plants might deter voles from eating roots, don’t expect these to block the possibility of girdling.
Ecosystems keep a pretty tight control on rodents and rabbits as is. If we simply focus on making a healthy, lush habitat, giving your trees the protection to make them “the one” that succeeds in growing to adulthood, the rodents can function less as your foes and more as your friends. The alternative is certainly not as pretty.
Such gardens arrive after some years of trials, where species themselves indicate their preferences, often in defiance of the dictates of literature. It is fortunate indeed that plants cannot read!
-Bill Mollison Permaculture ll
The sun bleeds a hotter light as it sets in the west, and this slope leans into it. It’s face to the setting sun, backed by trees to the east that swallow the gentle light of morning, days begin in shadow that lingers almost to the heat of midday only to be seared by the red light of evening.
The plants grow from these elements. Red-tan brushes of broomsedge grass (Andropogen) speckles the front in tall clusters like an artist’s idle tools, while at the back, messes of honeysuckle cling on piles of logs below scraggly chokecherries. Near the center, in contrast to the lush green Catalpa tree down the hill, stands the skeleton of what was once an apple tree. This is Mortal Tree, the sun scorched slope next to my house that’s becoming a vibrant, lush, productive food forest.
You might say I’m starting from scratch on this fourth acre of scrubby land; but I don’t plan on doing it alone. I know that every plant and tiny animal living here intends as much as I do to make the place burst with life. The aim of all nature is to create more life. My aim is not to take over, it’s to encourage and strengthen the process already at work. All this through carrying out a design.
Design works for me as the bridge between growth the garden wants, and yield I want. The more my design mirrors nature’s design, the more successful the project will be. In Mortal Tree, that design is a self-sustaining organism, every part interacting to make the whole, every part feeding the others, in care and nutrients, demanding little intervention from me.
Mortal Tree is the center of this design. Paths radiate from this point in fractile, lightning-like arms, and around this point the intensive planting starts -at the “nucleus” of the garden, growing out. The rest I let grow wild, mowing the grass and weeds with the quiet swing of my scythe, gathering excellent mulch. This mulch is fertilizer, moisture retention, and a tool for clearing space my edible plants and fruit trees need. It’s my main tactic, directing free growth of the ecology into my designs of hungry crops.
I’m experimenting with a no-till grain patch, fine-tuning PASSIVE gardening, enjoying the productive beauty in polycultures full of fruit trees and perennial vegetables. Nut and more fruit trees are scattered through the wild growth further down the hill that would perform far better if I had the mulch for them, but there lies my biggest problem:
It’s easy with the desire to power more plantings to overtax the free growth, and damage this delicate ecology. The current design has its limits. Over time, the area of free ecology I harvest for mulch is becoming smaller than the area producing food. What will happen when the need for fertility is greater than the supply?
I watch for what the garden offers. Mirroring the designs of nature in the yields, the design is improving. I’m using running plants to manage weeds, plants that produce massive amounts of mulch in the organized plantings to cycle nutrients and provide cover that protects the ground, and nitrogen fixers that can meet high demands of the hungry production plants. Slowly but surely, the two ends of the equation -wild carefree and productive, labor intensive -are drawing close.
I have to remember design is only so good as the nature that informs it. Nature is only so good as the life that fills it. No matter how refined my designs become, they are still nature. They house the light that bleeds from the sun, stretching up as growing plants, spuring on change in every aspect. Sometimes that change is good, sometimes not so good; but with the hope of achieving an ever more harmonious design to harness this light, through the changes each day brings, this garden, and its designer, lean into it.
For those of you new to this blog, “The Garden of Mortal Tree” used to be my About page, but after placing it in the Visual Archive, it fell out of existence. This is a major overhaul of that page that better reflects the present Mortal Tree.
Sunchokes is number ten in the Top 10 ground covers for food forests series I started a while ago. To help put everything into perspective, I made an infographic.
The ground cover branch on the visual archive has links to all the original posts if you would like to find out more.
In general, the layout from right to left are ground covers that do well in established beds, to plants that simply wipe out other plants, and are excellent for bed building.
If you’re wondering how to share this on your own social media pages, try the share buttons below the post. I have most social platforms available for sharing.
I’m using the the term “dynamic mulch” to describe the ground covers, because ground cover has a rather flat connotation. Most gardeners think of them as useless plants that do nothing better than excessively clog the soil surface. They have much more potential.
I’m suggesting these plants as tools, not just for blocking weeds, but actively removing weeds, making use of otherwise useless plants through careful combinations, getting food from ground cover, improving the quality of the soil, and feeding other plants through their well calculated use. With the correct use, resulting from a more dynamic comprehension of plants, we are suddenly on the brink of an entirely new level of sustainable, productive, passive agriculture and gardening.
The infographic, and the Top 10 series are part of a bigger surprise to which some of you closely following me have probably caught on. It should be ready before the end of the month. My apologies for making you wait, but I assure you, it will be worth it.
Sunchokes, or Jerusalem artichokes (Helianthus tuberosus) are not so much a stable ground cover as masterful bed builders. They don’t just block, but obliterate grass lawn, taking the place of bed building mulch if handled correctly.
Its home is the American prairie biomes, where it stretches for sun among massive grasses and other very competitive plants. Placing it in the standard lawn, full of short European grass species, or even an overgrown field is like releasing a saber tooth tiger into a playpen with modern house cats. It’s a brute.
It begins by pumping nutrients from deep in the soil to power billowing clouds of leaves rambling up sometimes 15ft tall stems. At the end of the season, less fortunate species smothered below, it sucks all the nutrients gathered in its stems safely into the underground for storage in its edible tubers. Every year it sends out runners, some species more aggressive than others. One variety, “Supercluster,” Oikos Tree Crops sells is supposed to be well behaved, but most are decidedly imperialist, surging several feet out in all directions every year as resources allow. As long as it fills its nutrient reserves every year, the size of the open field it inhabits is its only limit.
To unleash the beast, get a bucket of the tubers in fall, and with a shovel, make little slits in the ground about one foot apart, inserting the tubers deep enough they aren’t exposed, and walk away. The days of the nearby plant residents are now numbered.
Don’t worry next spring when the tubers don’t sprout early. Sunchokes don’t like frost, and wait until late in the spring to pop up their furry little heads. I have planted these into completely unamended yards where lawn grass wasn’t even happy, but the ‘chokes still grew well. Results of removing grass and patch expansion are best if the patch is left a year or two before harnessing it for actual bed building.
It is very difficult to put strong beasts like sunchoke to use with brute force. You have to outsmart them. This you do by pinpointing their one weakness, and suddenly you have them in the palm of your hand. Because exploiting this weakness is so effective, I must go begging to my friends for new tubers in fall because I have accidentally wiped out my propagation patches.
I have quite a hard time removing their disbelief. Sunchokes are otherwise known in the gardening world as hard-to-chokes, which is why I don’t recommend digging up your newly cleared bed to remove the plants. I have never seen this work. Though you could swear all the tubers are removed, the plants always return. Some varieties were selected from patches sprayed with roundup -and lived.
Biologically, sunchokes are impenetrable tanks of ecosystem war, and have the potential to become the worst weeds for your new planting. I would not in any way suggest their use anywhere near your garden if it wasn’t for the one gap in their armor.
You see, ‘chokes go all out to ensure they get as tall and bushy as they can. Having invested every last bit of stored food from their tubers into the above ground stems, it’s as though the plant stood on top of the ground and could just be gathered up as a pile of stems to be placed somewhere else.
I discovered this one year when a particularly healthy, bushy specimen blew over in a windstorm, partially uprooting it. I broke the plant off, cracking up the lush growth to mulch the bed, expecting to see the plant return next spring. I was surprised when next year there was nothing.
Later, in a very dry year, sunchokes were the most lush thing in my food forest to feed my rabbit. She liked them, so I would snap off the growing tips, let the plants branch off to the side, and snap of the side branches to make rabbit happy. I started this when the plants were about 5ft tall, leaving about 4ft stems that in turn could return their nutrients to the tubers. Nevertheless the plants that normally topped ten foot came up the next year anemic, and dwarfed, barely reaching three feet.
The exact point in time when they seem most vulnerable is just before bloom at a certain time when the growth of leaves changes from being as tightly stacked and lush as possible, to becoming a bit more sparse, the stem getting harder, and the flower buds showing up quickly afterward.
Flowering, and in fact most dieback processes of plants, are accompanied by the production of ethylene gas, which in the ‘chokes I would guess also begin the back flow of sugars in the leaves to the more complex carbohydrates in the tubers, and oxidation of the stem fibers, making them woody and brittle. Cutting ‘choke down just before signs of this hormone’s activity seems to be their secret weakness.
In my climate, this means cutting the plants off about a foot tall in July. It is helpful to leave some stem to make lots of side shoots. A second cutting, about a month later, to remove the side shoots and what’s left of the stem, perhaps even some roots, in my experience, weakens the plant beyond recovery.
Some gardeners I have explained this method to ardently insist I’m wrong. They cite their own experience of mowing sunchoke patches for two years and the ‘chokes just growing up over and over again.
I have gotten excellent results with the method in my experience. That they were only a few years old unlike the decades old patches in these other reports may play a role. I doubt it though. On the one plant that blew over I saw a very large clump of tubers which I left in the ground.
Perhaps it is more a question of the plants adapting to growing less each time they are cut back, developing a sort of stunted homeostasis. They may have grown more miserly with their output of stored sugars. I think it is imperative that you allow the roots to put maximum growth above ground, then sap the last little bits of strength out of them with subsequent cutting.
Be cautious of course in planting the sun chokes and letting them run wild. If you closely follow the details I have given, I am confident you can get very similar results. Feel free to let me know how it goes.
Hacking off all this biomass leaves a lovely, thick mulch for planting into next spring. Grass is usually gone by this time. Adding some grass mulch early next spring ensures establishment is smooth the next year, but very little is necessary compared to normal bed building. If used well -in conjunction with the other ground covers, sunchokes are a real workhorse, with the potential to carry your efforts to the blissful state of an established, productive, ground thickly covered food forest.