December, 2022
In which we build and protect our precious soil
Winter comes with a sputtering start. It’s now December, a month who — though her bulk is in Fall — is mostly closely associated with the Wintertime, and in the past few days we’ve had daytime temperatures in the low, steamy 80s and nighttime temps falling toward freezing; clear bright days, foggy morning, evenings thick and wet. Seasons are difficult to pin down. We always seem to be between two, or just coming out of one or just about to enter another. The harder we look, the more difficult it becomes to see not only the division between Seasons but even the Seasons themselves. They are fleeting. Elusive. Did we have a Fall? Is it finished? When was it — when did it peak, and when did it begin?
After all, the Seasons are not Real. They are not things or facts with any substance, nor even manufactured concepts with any profound relationship to the Way Things Really Are. They are (or were) expressions of how it is to be human in a complex and confusing, ever-shifting world. We have a Fall because, after every period of Warm there comes a time of Cold, and so we have carved out the Fall as a time to store up and hunker down and prepare for that Cold. We have a Spring so that we will know when to plant and what to hunt, et cetera, et cetera.
But over time these Seasonal categories got even more muddled up. They’ve become increasingly self-referential and confused, especially as culture and communication have grown more global. No longer are the Seasons helpful totems or categories to describe our own shifting environment throughout the year.. No, Winter always now refers to the Platonic Ideal of Winter — thick, blanketing snow; cold, crisp nights; bare, deciduous trees; frozen ponds; sledding and caroling and cocoa and mistletoe — and so we hear it said that we just don’t have a winter at all down here. Or that we “didn’t get a Fall this year.” Or that our Fall is really a Second Spring. All kinds of wack-o statements that only make sense if we take as predicate truth that these Mythical Seasonal Archetypes are real things at all, rather than invented descriptors of What It Is Like in a given region during a given month or time of year.
And yet, for what it’s worth, the Winter is nearly upon us.
So let us dwell for a moment at least on what that means for us, the Gardener, and our charge: The Garden.
~* MVLCH *~
Mulch can be applied in all its uses at any time of year. Its insulating properties are effective in helping to weather any extremes of temperature, whether hot or cold. In more mild weather, it can smother weeds and provide habitat for predatory insects and other beneficial organisms. It reduces the erosion of topsoil from high or sloped areas and alleviates compaction in low spots. Its facility of absorbing and holding water can prevent flooding and pooling in the Rainy Season, as well as retaining/distributing it in times of drought.
Over time, through all these seasons, the mulch breaks down and metabolizes into a rich humus, contributing to the topsoil as well as protecting what already exists.
This is how topsoil is generated In Nature, without human intervention. Generally, we do not find Compost Piles In Nature — certainly not Hot piles constructed from careful ratios are regularly turned. No, it is a much slower process than that, a process fundamental to the great bulk of all terrestrial life and ecology.
In the forest, fallen trees and forest duff — and in the prairie, withered grasses — together with decaying roots and the rotting corpses of animals and the efforts of countless other organisms, digest and are digested into a fertile substrate wherever there is land and life.
But this glacial process does not jive with Modern Agriculture or exploded human populations, so we’v reverse-engineered from it two dueling practices: Compost & Mulch. For whatever reason, Compost seems the flashier of the two, and has commanded more attention in the Garden, Farm and Homestead scenes. And it is miraculous indeed!
By collecting that organic material that would otherwise have decayed in place and centralizing in it a well-balanced pile — and then augmenting that pile through our own labor by turning it and supplying it with oxygen — we have greatly sped up the process and can generate a fine, uniform and fertile product at a breakneck rate. But in that project we have selected for one beneficial outcome (production of compost as a soil amendment) at the expense of other, equally vital outcomes.
Enter: Mulch.
In mulching our gardens and landscapes, we are returning to them the leaf litter and forest duff that have grown so scarce in the human-centered environment, and with it many of the benefits left behind in our emphasis on Compost. In this way, Compost and Mulch are twin disciplines, two sides of one coin. A healthy Garden Practice must necessarily incorporate both elements — and the one must complement the other.
So what are these benefits of distributed Mulch & Litter? We hit on them briefly at the top, but let’s expand:
Toted most often perhaps is Mulch’s capacity to insulate against temperature extremes. This is why, though it can be applied year-round (and ought to be left in place till it is fully digested), it is most often applied in advance of Summer’s heat (in late Spring) or Winter’s cold (now). Doing so will protect plants’ tender feeder roots, which remain generally near the surface, by effectively extending the earth to a few inches above them.
The earth is an excellent insulator already — think of buried root cellars and seed vaults or the cool water in underground pipes at all times of year — and by Mulching over roots we are better able to take full advantage of that insulating capacity. The same holds true for burying dormant bulbs and tubers and any perennial herbs.
Another benefit to our gardens is the suppression of weeds. Mulch on the one hand can smother unwanted plants by its sheer weight, but even more crucially, it can prevent their germination by blocking out light. Not all weed seeds require light to germinate, but a good portion do, and those that do still sprout and push through the Mulch will be fewer and easier to spot, and are far easier to pull from a loose layer of Mulch than from bare, compacted soil.
One benefit that is often overlooked is Mulch’s ability to reduce disease pressure in the garden. Many disease pathogens are soil-borne, and spread where soil is splashed onto low-growing leaves or anywhere the above-ground parts of a plant come into direct contact with the soil. This is particularly true of and important to annual vegetable plants, which can be very tender and become increasingly susceptible to certain diseases as the plant ages and the seasons turn.
Mulch’s most magical qualities relate to its ability to absorb and store excess water. As noted above, this can prevent flooding and erosion during rainier times, as well as holding and making that water available to plants during times of drought. Even in mild (not overly-wet or -dry) periods, this can greatly reduce water waste and bills.
The rains of SE Louisiana are intense, to say the least, and without a protective covering, topsoil washes right off of any slope, taking with it its beneficial Minerals & Nutrients, and over time homogenizes the landscape into one uniform low spot. Even where there is no grade to wash down, the topsoil is ruined by compaction from the pounding rain and its nutrients are leeched away from the surface. By Mulching we can better allow for a varied and diverse topology, with fast-draining high spots and slow-draining swales, allowing for a variety of environments and a healthy distribution of functions in the garden. Diversity, as we have said, is the hallmark of a healthy (i.e. Self Regulating) garden space.
Ultimately though, what we are doing by applying Mulch is adding Organic Material to the garden, just as we might do with traditional Compost. Over time (years, likely), this material will decompose in place, adding to and growing our existing topsoil. The humus so produced is complex and fully colonized by thick webs of native fungi and other lifeforms, creating and indispensable/irreplicable, finely-constituted soil structure (or “Tilth”). This is the stuff Garden Dreams are made of.
But not all Mulch is made equal, and not all Mulch gives us this desired outcome. So far the type of Mulch we have been discussing is that of (dead) plant material that we bring into our garden (from elsewhere, mostly). This makes up the bulk of all Mulch applied in home gardens everywhere. There are, however, other types.
There is, for example, Plastic “Mulch,” which is to say Sheets of Plastic, rolled over and pinned onto the soil surface, with individual holes for each chosen plant. We see this often in small- to medium-sized market farms. The scheme synergizes nicely with Drip Tape, which can be put together to surgically irrigate each hole and nothing else.
This, like many modern shortcuts, is a tempting proposition, especially for gardens with a high Garden-Space to Gardener ratio (e.g. one farmer/gardener managing multiple acres) or in regions where water is scarce, as it can greatly reduce water waste and all but eliminates weed pressure. You can probably guess our feelings about covering gardens in single-use plastic, but even if we expend the considerable energy and effort to roll up, save and reuse our plastic, we will have still sacrificed perhaps the most elemental functions of Mulching in our pursuit of artificial convenience. We will do well to consider, if we are tending more space than we can manage, that in many cases we can save on labor in the long run by facilitating natural processes and employing the help of non-human systems and organisms, and that, if we have more space than we can manage alone, we perhaps ought anyway to share that space.
The other type of Mulch worth dwelling on for a moment here is Living Mulch. This is the creme de la creme of Garden Practices, to my mind at least. Most often we may encounter this as Cover Crop, which is seeded over plots between plantings of vegetables or other crops, and then cut or crimped and turned into the soil a few weeks ahead of planting. These cover crops are usually legumes, grasses or other ground cover, they are most effective as a mixture. There are cover crop mixes specifically developed for different regions, for warm or cool times of year, but generally anything growing and returning to the soil is beneficial and far better at least than bare soil. There is much, much more to say here, and one of these months I’ll write a whole newsletter all about cover crops, but for now we’ll leave it there.
Another approach to Living Mulch is to cultivate more permanent plants that accumulate via deep roots Minerals & Nutrients that they bring to the surface by dropping their leaves. This can be as simple as a deciduous tree that blankets the soil each Fall as it loses its leaves (just as happens in the Natural Forest), or we might employ a “Chop & Drop” strategy, physically returning material to the earth by coppicing or aggressive pruning. A favorite plant of ours here at Too Tall is comfrey, which ticks these boxes all nicely and functions as a wonderful living mulch. Again, I may some day send you all a missive dedicated entirely to Comfrey. For now let’s keep talking Mulch.
The makeup of Mulch can be any number of things. We might use hay or straw or other agricultural (by)products, such as rice hulls or peanut shells or bagasse (spent sugar cane). We can use raked leaves or lawn clippings, shredded paper or flattened cardboard boxes (when using paper or cardboard products, we should take extra care to water them in well once applied, so that they do not become brittle or blow away). Among the most common products and by far the most used in our gardens here at Too Tall are arborist chips: mixed, chipped tree limbs and other debris.
If you’ve got a good spot with easy truck access, you can flag down an arborist somewhere and ask them to dump their chipped material at your garden (in urban areas they usually have to pay to dispose of it). Arborists can be fickle and poor communicators, but if the spot is accessible, and especially if you can take multiple loads at a time, they will most often reward patience with a bounty of beautiful chipped material. The best thing to do is to get more than we need at one time, and to let it mellow and age in a pile for use as needed. Many or most of us do not unfortunately have such an ideal dumping spot, so this is yet another area where we should consider collaborating and sharing space with other gardeners in our area.
How we apply the Mulch depends on our specific situation and intent. In garden beds around existing plants we should shoot for a depth of 2-4”, as much more than this might be counterproductive and actually prevent water from reaching thirsty plants. In most cases, especially around woody plants, we should keep the bases of our plants clear from Mulch, ideally out to the drip line (the perimeter mirroring the reach of a plant’s outermost limbs). We can forgo this and bury plants, bulbs and tubers that need to be protected from cold e.g., but we should never pile Mulch against the trunks of trees or shrubs. Holding moisture and decay against the plant like that is a surefire path to illness in woody plants. Once clued into this, we will start to see (well meaning) Mulch Disasters in landscapes everywhere, with leaves or chips piled into a volcano formation around the bases of trees, especially. We should be careful also to keep fresh or undigested woodchips on top of the soil surface, rather than mixed in, so that they do not “bind up” and make unavailable the nitrogen in the soil as they are digested.
In open areas and plots that we have no immediate plans to cultivate, we might Mulch more heavily to keep the weeds down and more slowly develop the soil for future planting. A good method here is Sheet Mulching — covering the soil surface with cardboard, burlap, even wool or cotton rugs, giving it a good soak, and then burying with a foot or more of our chosen Mulch Material (again I will recommend woodchips).
Of course there is more that we could say about all of this. And, as with all integral components of our Garden Practice, a discussion around Mulch bleeds quickly into other (separate?) realms. Already we have touched on Cover Crop and Compost, but we could just as easily delve into Soil Biota, pH, Beauty Bark and Other Abominations, or any of a bazillion other topics. But you’ve heard enough from me for this month, and there are many more months come.
So, till then, take it easy, friends. And Mulch your f*%&n gardens.
Mulch me Senpai