Ecology of annual vegetables in sheet mulch

I am wondering about the ecology of annual vegetables as it impacts their use in sheet mulch. Some people say that annuals of any sort evolved to grow in bare disturbed soil, so the tiller (or at least the shovel) is necessary to continuing good yields from them, or at least that it would continually be necessary to import more mulch materials. Also, sheet mulches should be fungi dominated, and this should be against a healthy stand of annuals, and similarly, sheet mulch ought to keep the soil cooler, again working against annuals. There is some big names in this camp; the Bio-intensive practitioners among them.

Of course, I entirely agree with the use of more perennials. But they take time, and in my climate nothing can quite take the place of squash, tomatoes, and beans. Greens are easy.

So, is an annual plant's niche bare soil? Or is it just an abundance of sun, free food from disturbance debris, and a lack of competition to smother their seeds next year?

Which is more like a natural disturbance: a tilled bed, or a sheet mulched hugelkulture?

Could we maybe mimic natural patterns better with a shovel?

This in not to be taken to mean that I am against sheet mulching. From my reading, I think it is a great technique. I have read Edible Forest Gardens, Gaia's Garden, The ultimate Guide to Permaculture, etc. However, I am now implementing it for the first time myself, and trying to explain it to others, and I can't quite see how it mimics natural patterns as far as annuals are concerned. It would be great if someone could explain the ecology of this.

I think that you are right in that many annuals are adapted to start growing after disturbance events and many need a bare-soil seedbed. Trying to grow them, particularly from seed, in sheet mulch or any mulch for that matter is swimming upstream. I have had better luck with transplants and plants growing big vigorous seedlings from large seeds, in warm seasons. There's also the significant benefit of solar heating on bare soil in colder seasons. So there will always be disturbed niches of bare soil for getting these plants started, and in some cases, for growing them for most of their short lives.
But the broader principle still applies....what happens in nature is small patches of disturbance....a blowdown here, a sandbar there, a burn-site somewhere else, scattered through a larger matrix of mostly perennial vegetation. And so to mimic nature well, we should always slant our designs towards perennials, towards covering most of our landscapes with perennials, and meeting most of our needs from them. And not just perennials, but something that mimics the natural climax vegetation of our area....forest in some cases, prairie in others, etc. This is in stark contrast to mainstream agriculture which consists of vast landscapes graded bare of all vegetation regularly and forced to grow only annuals year after year.....

Interesting question. I would think things you will probably be transplanting like tomatoes, peppers, etc are having a disturbance during transplant. Perhaps putting seeds in during direct seeding is enough of a disturbance too. How much disturbance makes a difference. And does the benefit gained from the disturbance outweigh the negatives such as promotion of weed germination?

I've had great success with growing all types of annuals from transplants in sheet mulch. I think the real question you should be asking is whether growing annual vegetables from seed can be done at all without disturbing/destroying an ecosystem, setting it back to square one. These plants rely on disturbance to germinate; if your plan is to make an ecosystem that grows for years without disturbance, then annuals (at least growing from seed) will not fit into that plan... or if they do fit, it will be very close to the house. Maybe even inside the house.

I've been having a similar mental debate about whether aquaponics has a place in permaculture. After running an aquaponic system in my basement for the past year, I'm donating the whole setup to the local tech college for them to use as a teaching tool, because its need for continual maintenance doesn't fit my hands-off gardening ethic. (Case in point -- I just realized I forgot to feed the fish this morning! Dammit!) If high-maintenance systems like aquaponics, greenhouses, or indeed annual vegetables have a place in permaculture, I would say that place is exclusively zone 0 or 1, where they can get the attention they need, and where ecological disturbance is pretty much inevitable anyway because that's where we putter around.

Thanks for you replies.

I never thought of that before. A planter of potting mix is a seriously disturbed ecosystem. Once it has a tomato in it, that patch of disturbance is moved to the undisturbed sheet mulch. The same would go for a small mound of compost placed on a sheet mulch, and a squash seed stuck into it.

Drawing on Edible Forest Garden's principle that disturbance and patch ecology is what drives ecosystems, and combining this with what is said above, I think that annuals transplants or large seeds being placed into sheet mulch would actually be a good mimic of certain ecosystem functions. Ants heap up and loosen soil, and store a bunch of seeds underneath. Rodents dig a burrow, and stash seeds or roots in it. We plant heirloom tomatoes in a sheet mulch full of comfrey, Good King Henry, and Red clover. (A meadow ecosystem, which we maintain; it is our habitat. )

Of course, broad-scale disturbances are not at all well mimicked this way, but I suppose they only happen infrequently.

So, is this a good understanding of sheet mulch annual ecology mimics? I am interested in your feedback.

Gilbert Fritz wrote:So, is this a good understanding of sheet mulch annual ecology mimics? I am interested in your feedback.

I don't know, but I hope so. I really like the idea of it. Also, even a footprint really is a disturbance. Some seeds won't germinate unless they have a solid soil contact, thus plants that like compaction grow in traveled areas. So, I wonder if that would be true for annuals that are direct seeded: i.e. a little pressure in to the mulch and they will germinate.

I believe the disturbance needed is not that much.
I also believe that annuals can thrive in a bacterial-fungal situation as opposed to a bateria-only situation.

Weeding is a disturbance. Harvesting is a disturbance. Both allow holes where light gets in and germinates the seeds. As long as the soil is moist and the seed is in contact with it, it will germinate and grow.

But...I keep a light scatter mulch, not the bombproof 10 inch one one like Toby proposes. That would need transplants, in my opinion. Really tough growing seeds in tall sheetmulch.

I also think that the balance should be shifted toward perennials. I'm just planning on keeping most of the annuals at the forefront so they will always have light.

William

not all annuals are fussy and need to be pampered, or are in need of that soil disturbance. though some of them are much more intensive and do perhaps deserve the questioning.

even though i am very into growing perennials in general, seeing all the anti annual stuff makes me want to defend them! or at least some of them.

i would think that just the wonderful family of brassicas should be enough to raise the annual plants out of the shaming!

theres certainly some annual plants that reseed without soil disturbance of any kind, again many of the brassicas, and ARUGULA...possibly i have gotten more food from various brassicas and arugula, than anything else i have planted, and not neccassarily ....excessively disturbing soil or any pampering.

while i think there are some annuals that bring up these issues, i certainly wouldnt say that someone should never plant annuals, especially if they enjoy them and they are suited to the climate. and especially the self seeders, low maintenance plants.

I think that Toby recommends
1. transplants
2. opening spaces for seeding.
3. removing in spring if you want hotter soil temperatures sooner.

Seeds need to be in contact with soil to grow well. Believe me, I have tried seeding on top of heavy mulch and the seeds germinate, don't find the soil to stick a root into, and then die. If they're lucky some disturbance knocks them down to the soil.

William

I have been thinking some more about where annuals fit in to ecology, and, therefore, where they fit in to Permaculture.

I think that even if we got the perfect perennial food systems growing, it would be wise to plant small beds of annuals every year, thus keeping up our seed stock. Then, if fire, flooding, tornadoes, hurricane, landslide, or war swept through, destroying our trees, we could replant all that bare land with annuals, saving it from erosion, and generating enough food to survive on till our trees were back into production. This is an annual plant's use in Creation; to act as disaster cover and food. (It would also seem a shame to let the breeding work of millennia got to waste.)

So if, as in my post above, annuals partly survive in perennial ecosystems because of animal caused disturbance, this makes a lot of sense. Animals plant annuals, and when a disaster sweeps through, annuals feed animals. If this is a true natural pattern, then it would seem to be a good one for us to replicate.

I just saw an example of this the other day; a squirrel burying a large tomato in a lawn. It carefully dug a hole, planted in, and patted down the soil. If the lawn was not sprayed or mowed, there would be a tomato plant next year.

I would like to get some real ecologist's take on my Animal disturbance dependent annual idea: small populations of annuals kept viable by animals, to feed the animals (and protect the landscape) in disasters.

You will find the ideas you're after in the work of Allan Savory and Holistic Management. Huge ecosystems in drier climates....grasslands, semideserts, and the like; thrive best with what he calls "animal impact"....precisely the sort of disturbance, trampling, manuring, and seed dispersal you are envisioning. Arguably, he says, well managed herds of livestock can be key to regenerating soils and landscapes degraded by the improper management of the very same animals!

Ben Stallings wrote:..... if your plan is to make an ecosystem that grows for years without disturbance, then annuals (at least growing from seed) will not fit into that plan... or if they do fit, it will be very close to the house.....

I would disagree... livestock and wild fauna do an excellent job in the facilitating of annual's reseeding, in a pasture/woodland setting


Edited to add: finished reading thread and realized my point was already made.

Dave Jacke's book talks about forest "climax" being a shifting mosaic of disturbance and succession. So, yes annuals fit in where there have been disturbances, the point is to plan those disturbances in a large enough system that you can be starting annual culture every few years in a new place, then organizing the sucession so you get some benefit from that as well.

This is a type of traditional agriculture that works in 10-20 cycles and annuals are a part of that cycle, just as much as fruit bushes, trees and wood products.

W