|As I've explained before, we've got raised beds here. Let's call the big beds #1, #2, and #3.
Bed #1 is full of purchased, brought-in topsoil. It was first lined with cardboard to suppress the weeds and then the soil was placed on top. [NOTE: I was just informed that cardboard is banned from organics because it has formaldehyde!] When I arrived, it was chock full of weeds - mostly nutsedge, some bermudagrass. Both of those weeds are monsters because you need to eliminate the entire root system or else they come back. And in this case, the root systems went down to the original soil, below the raised bed.
Bed #2 is full of purchased, brought-in topsoil too, but it has some sort of synthetic material on the bottom that REALLY suppresses the weeds. It also has drip irrigation installed. It's planted with chard, sunflowers, potatoes, fava beans, nasturtiums, and parsley.
Bed #3 is empty, with the soil below it covered in bermudagrass. Some heavy weeding is required unless one turns to chemical weapons or a synthetic cloth that the weeds can't get through. The cloth won't kill the bermudagrass - it'll continue to grow around the box - but it will keep it out of the soil you bring in at least.
Obviously, we've got some work to do on Box #1 (weeding) and we've got decisions to make about Box #3. Do we bring in soil? Do we stick a synthetic cloth on the ground under it? Or do we do something else?
Others in the household like the use of the cloth and the brought-in soil. I don't. For one thing, I don't think it's sustainable to produce soil elsewhere and then truck it around to satisfy suburban and urban gardeners who want a quick, easy garden. I'm also skeptical about what's in the soil. Factory farm chicken shit? Steer manure from a feedlot? Maybe. Organic standards allow shit from conventional animals.
Then there's the matter of the cloth. Yes, it will save you from weeding. But it also ensure that the weeds are there permanently and you won't be able to fully get rid of them without removing all of the soil from your box to do so. (At my old place, I found it very frustrating that the roots of the bermudagrass went under the sidewalk and all I could really do was just remove the stuff every time it grew out from there.) I'd like to REALLY get rid of the weeds.
But besides that, how do you build your own soil if you're essentially just planting in a pot? You can build it on top, but not below if you use a cloth to keep the weeds out - because it also keeps the roots of your plants from going down too far. And in a dry place like this, that's critical because they can't go down to seek water.
Additionally, one group of plants I like to include are called "nutrient pumps" - plants with very deep roots that can go down to get nutrients from the subsoil and bring them up to the surface where they are accessible. You suppress weeds with a cloth and suddenly, the idea of using a nutrient pump no longer works because deep-rooted plants can't go below the cloth.
And back to the idea of bringing in the soil, if you have a bed full of weeds and you stick a foot of topsoil on top of it, now you have to dig deeper than a foot to eradicate the weeds. Sticking a big raised bed on the ground and filling it with soil makes it much harder to really get rid of the weeds. (That's not true of every weed species, but it IS true of the two we've got.)
When I had my weeding party a few weeks ago, I had everyone work on Box #1. Within days, the weeds were back. They removed a lot of nutsedge - but not all of it. Not even remotely. For the past several days, I've spent hours working on that bed each day, digging all the way down to the original soil to pull out ALL of the nutsedge. I'd like to get most of it taken care of and then I suppose I'll just pull the rest of it as it comes up and hopefully starve the roots of photosynthesis.
Of course, that also involves removing the weeds around the box as well as in it, so I've been doing that as I go. The last thing I need is for a bermudagrass rhizome to creep under the bottom of the raised bed after I finish with weeding and get the box planted.
The weeding is a TON of work - but it's not something you have to do in this magnitude more than once if you can maintain it. And that just means removing these two species of weeds from around the box and keeping them under control over time. We did it in my old garden and it worked.
I found that the brought-in top soil is somewhat sandy and silty, but the soil below is clay. That means that any water that the box gets will seep right through the sandy/silty layer quickly but then it will not easily seep into the clay. I'd prefer a mix of the two, instead of the two extremes we've got. Clay and organic matter hold water and nutrients best, but sand and silt allow water to percolate down more easily. I think all of my weeding resulted in some mixing of the two layers (I hope).
I'm also not a huge fan of drip irrigation that is set on automatic so that it delivers shallow waterings on a regular schedule. I want to train my roots to go deep (if they can, i.e. if there's no synthetic cloth lining my bed) and you do that by mimicking rainfall. You completely soak the soil and let the water percolate down, down, down. The top layer dries up and the roots need to follow the water down as that occurs. When the plants begin to look a bit droopy, then you water heavily again. (I also use a ton of mulch to minimize evaporation off the soil surface, particularly in the summer here.) Ultimately, I'd love to really do dry farming, when and where it's possible.
Another organic practice I'm not a fan of is the use of organic fertilizer. Much of it is made with fish hydrosylate and seaweed. It's essentially giving your plants a quick shot of nitrogen. But soil microbes - which organic gardeners rely on to feed their plants - consume both carbon and nitrogen.
When you use organic fertilizer that is so rich in nitrogen, the microbes will also consume a bunch of your soil organic matter (carbon) at the same time. And healthy soil requires enough organic matter. You might get a quick spurt of growth in your plants - but it will come at the expense of your soil's long term health. And giving plants too much nitrogen makes them more attractive to insect pests.
The down side of doing things "my way" of course is that you end up waiting a lot longer for results and you do a lot more manual labor. I've spent days pulling weeds. My fingers are entirely calloused at this point. And I expect we'll grow nothing more than sunflowers, fava beans, and non-edible cover crops in much of the yard this winter. Fortunately, we've got enough space and soil that we can also grow food too. I'm planning to fill box #1 with lettuce, radishes, carrots, and peas. And somewhere, we'll absolutely grow some kale.
But I'm in no hurry. First, I want to weed box #1, then I have a plan to build the soil. And then I'll do the same in another box. I don't plan to grow very demanding crops in most of the yard this season. I'm more focused on building the soil than getting a huge crop of broccoli. And if we don't install use drip irrigation, then I'll be out there watering it regularly. To me, that's worth it. To my roommates, maybe not.