Brainstorm for a sustainable long-lasting flower bed structure

As part of my decade-long plan to get rid of my lawn, I'd like to setup an herb garden in the middle of what is left of my small front lawn. I'd thinking of a round raised bed of about 4-5 feet in diameter

Criterias:
- It needs to be somewhat acceptable to neighbours, since it will be one of the first thing one notices when looking the house... but we live in a fairly tolerant area, no HOA.
- It needs to be raised at least one foot, since there are moderate concerns of lead traces in my soil (nothing dramatic but above the baseline of pristine non-urban soil, so I'd rather bring in some clean soil in)
- I'd like something that will last a long time
- It should be fairly easy to mow the grass around with a trimmer
- We're in a fairly humid climate with below-freezing temperatures in winter and lots of snow.
- I'm open to DIY or commercially available products. Bonus points if it uses materials that would otherwise go to the landfill or be suboptimally recycled.
- We do not have access to large amounts of recycled bricks (the main local brick-laying company systematically recycles bricks, which is awesome. But that also means that there are no longer free bricks all over the place )

The easiest solution is probably to buy concrete blocks, but I'd like to explore more sustainable alternatives.

I'm daydreaming about eco-bricks (plastic-filled plastic bottles) covered with cob and then a small layer of cement? But not really sure how cob performs in the context of a garden bed (i.e. always in contact with moist soil).

Recycled HDPE interlocking bricks might be interesting, but I'm not sure if it's commercially available?... We don't generate enough HDPE trash to make that ourselves. (I just bought recycled HDPE furniture and I'm really impressed by the quality of that material)

Any crazy ideas we might consider?

Kena Landry wrote:
- It should be fairly easy to mow the grass around with a trimmer

I'm sure you will get other help with the structure itself, but I can tell you how I solved the quoted issue.  Every structure, tree, guild, whatever, that is in the part of the yard that is mowed has a ring of comfrey or a ring of hostas as the outermost planting.  You'll never have to weed-eat again, you can just mow right up to the plant.  The mower will go under the leaves and you don't have to trim anything.  It's a huge time saver if you like your lawn neatly mowed.

For your circular bed can you do something like this:



From this thread

Then use Trace's suggestion of planting hostas around the outside?

Trace Oswald wrote: Every structure, tree, guild, whatever, that is in the part of the yard that is mowed has a ring of comfrey or a ring of hostas as the outermost planting.  You'll never have to weed-eat again, you can just mow right up to the plant.

That's a great idea. I never thought to use large-leaved plants as the border itself...

And it makes me think that instead of a raised bed, I could dig into the ground to replace part of the original dirt with wood and twigs, build a hugel on top, and have that bordered with hostas.

Kena Landry wrote:

Trace Oswald wrote: Every structure, tree, guild, whatever, that is in the part of the yard that is mowed has a ring of comfrey or a ring of hostas as the outermost planting.  You'll never have to weed-eat again, you can just mow right up to the plant.

That's a great idea. I never thought to use large-leaved plants as the border itself...

And it makes me think that instead of a raised bed, I could dig into the ground to replace part of the original dirt with wood and twigs, build a hugel on top, and have that bordered with hostas.

Other possibilities are horseradish and rhubarb if you want more edibles.

If you make the outer edge square, you can also put pieces of heat-treated packing skid flat on the ground and run your mower right on the edge of it most times. The grass, if it's unruly like mine, will start to encroach, but the trimmer ought to be able to knock it back fairly quickly. At least you wouldn't have to use it every time.

I like Traces suggestion of comfrey - I've got some near a plum tree and the part of the lawn it's adjacent to, is definitely easy to mow. I don't worry if I catch the odd leaf. It can be chopped periodically either for mulch or to support your compost. My Rhubarb tends to die back in the summer - it's not in a place I'd water, so it may depend on your climate.

Personally, I'd go for wood before anything plastic. At least if the wood decomposes, you can make a hugel out of it. Plastic leaves a lot of "plastic dust" around.

Kena Landry wrote:

It needs to be raised at least one foot, since there are moderate concerns of lead traces in my soil

 If you aren't in a rush, growing sunflowers on that area for a couple of years, and then sending them to the dump, could get the lead down to a happier level. Sunflowers are used a lot in Britain for decontaminating old industrial sites from lead.

If your up for a little manual labor theirs always compressed earth, with a little cement as a stabilizer it will last for a very long time. And I always liked the look of compressed earth walls, like a painted canyon.
https://www.motherearthnews.com/diy/rammed-earth-garden-beds-zm0z14jjzkin/

I have made my beds out of large firewood rounds. I have included a picture. Mine are not terribly picturesque, since my main goal was to get it up fast. However, if you used rounds of the same length and roughly the same width, you could make it look tidy.
Longevity is an issue of course - my 3 year old bed is decaying, though granted I started with slight fungus eaten poplar. However, it is not hard to replace older logs with fresh, one at a time. If you have done a good job building your soil, it will stay completely put when you take part of the side away and stick a new one in. My soil is mostly rotted woodchips, with rotted wood logs in the center to reduce volume and with compost and manure mixed in. The rotten logs can go around the compost pile and will be gone in a year - if they don’t disintegrate as you remove them, in which case they are mulch.

If you have a lot of rocks, you can use them.  Building a freestanding rock wall is beyond my skill level, but a retaining wall is held up on the back side by soil😊.

A few guidelines:  
Place the stones two on one and one on two.
Place the stones so that they want to fall inward, backfill as you go.
Straight lines are not as stable.  (Think of trying to balance a playing card on its side… falls over, right?  Think of bending the card before balancing it on its side.)

Practice will teach you the rest.

In my area there are a lot of companies that produce beds from wood-polymer composite. They don't rot, they don't absorb moisture, easy to install yourself, easy to move if needed. Also it's easy to saw it so you can make beds whatever size or shape your want. Initially it's a decking material. I don't know the proper English term for it.

Many years ago, 15 or so, I built a couple of raised beds using old Trex decking.  I had to support it every couple feet or it would bow.  I used concrete stakes I had on hand and some screws to connect them.
I sold that place 3 years ago, but the beds were still going strong!

Ultimately, I caved in and went with pavers, which were available right now. Not ideal in terms of impact, but I really wanted my herb garden this season, and sourcing other materials could take a lot of time. At least, they should last pretty much forever.

However, I'm keeping all your ideas, as we have more areas to develop in our yard.

Thanks a lot!

(for the curious, in that picture you can see aronia, strawberries, blueberries + the herbs and the ornamental hostas/shrubs. All partially shaded by an old spruce.)

David Nick wrote:If your up for a little manual labor theirs always compressed earth, with a little cement as a stabilizer it will last for a very long time. And I always liked the look of compressed earth walls, like a painted canyon.
https://www.motherearthnews.com/diy/rammed-earth-garden-beds-zm0z14jjzkin/

The pictures in the link are gorgeous. Have you tried this yourself, David? In my climate, I'm not convinced they'd last, but if it weren't too hard, that might not matter. The beds I built are wood, so I *know* it's not going to last!

Thekla's rock walls look great. My local rock tends to be a jumble of all sorts thanks to the last glacier. I've got to find a way to make some piles up that are sorted so I can put them to better use. Last winter I worked with these rocks:

It's a sort of hugel/compost mash-up and if you look through the orange fencing in the background, there is a low retaining wall to even the land for an apple tree with friends (Rosemary, strawberries, Chives, day lilies and a few others).

Those angular rocks are GREAT to work with.  When I have been building with those, I worked several courses high, and 10 to 15 feet (or more) linear distance, and had piles and piles of rock to pull from.  The same rock might be placed and built upon multiple times, because its particular shape was absolutely required for the new spot… the the old spot had to be rebuilt.

I didn’t mention in my prior post that the biggest rocks go on the bottom, and as you place that bottom rock, you dig the earth to accept the shape of the bottom of the rock, and as you decide which face is the bottom, most important consideration is what surface you are creating on top, because that’s where the next rock is going to go…. And you want it’s center of gravity such that it wants to tip backwards into the soil, rather than fall out of the wall with only the slightest provocation.

Working with big rocks, roll them into place.

I find it very satisfying work.

100 gallon fabric pots are what I thought of first. https://greenerhydroponics.com/Empire-Fabric-Pot-Basic-100-Gallon-_p_87324.html?gclid=Cj0KCQjw5ZSWBhCVARIsALERCvz-NuEolRCO9tlpFvWnuWlgDxOybPbreWpaETvOj7wstQYrph1rEp4aAqe5EALw_wcB
But the literature says their lifespan is max 4 years.

Just a thought.

And, just a thought, the “fabric” pots are most likely a petroleum product, likely rightly classified as a plastic.  And if they last as ”pots” for 4 years, thence as micro plastic for the next ?thousand?  

4 years of convenience, a thousand (an estimate) of pollution.🙁

Plastic is so ubiquitous it’s hard to keep track of all the other solutions we need to come up with, as the petroleum industry makes it VERY hard to not utilize it.

The now make corner blocks (see photo below) that allow one to build rectangular raised garden beds.
They accept 2" X 6" planks of any lengths/widths that you want for your bed design.
They do make a really neat looking bed and all of your soil stays inside the bed.
Standard cement blocks are much less suitable as they move radically when the earth freezes.
I believe most of the big box stores carry these now.

ok, I have a low tech, low cost method that I use, in clay rich soil.
Let's face it, any use for clay is a positive. This method  uses the "plastic" form making potential of clay to your best advantage.
First I dig a "moat" around where the garden bed will be. I like curves. This will ultimately be filled with logs, branches, sticks, horse poop and seaweed around the bed which will soak up water all rainy season long, and release its mineral and poop enriched water into the bed all dry season. I will be able to walk on this most times, except maybe immediately after severe rain.
Then with the removed clay rich soil (from the "moat"), I build a hugel bed, dumping in logs and branches first, then the grassy side of the clods, grass side down second, layering everything up like a compost heap... poops, grass clippings, leaf litter, sawdust, grass clods... etc etc etc. And Chuck in some wormies from the worm bin, after talking to them kindly and not throwing them about at all.
Then I use the most clay rich soil from the bottom of the "moat" (swale) to make "cob". I guess it is not real cob, but something cob like using the materials on hand and freely available to me.
I shovel it into the bottom of a sturdy tub a few spades full at a time, chop it well, add seagrass (which is what I have) or other fiber such as straw, mix thoroughly, add water if necessary, and when I have something damp and cob like I build a low wall around the garden, ie inside the moat.
It looks good, and is basically free, while creating an almost self watering bed that is sucking up enriched water all summer long.
It works for me. I wish I could figure out how to add a picture.
I don't know how well the low cob wall around the garden will last. The oldest I have is about a year, and is doing fine. It might need some tweaking at some point, I m not sure.
Hugshugs from winter New Zealand where I foraged two full bags of kelp from the seashore today, and used them to part fill my latest "moat", completing one of the three garden beds where I will grow kumara next warm season.

Check if you are close to a commercial type plumbing supply, usually in industrial parks. The big commercial bundles of pipe are shipped in bundled. They throw away these square holders that are raw 2x4s bound with a strap. No one wants to burn them because of the metal or plastic strap. They don’t go back to vender because they are built around each bundle of pipe. Incredibly stout, stack stable ( no need for any bracing) multiple sizes, no nails no paint no preservatives. And the plumbing supply is grateful for you to take them