The making of concrete is one of the most fossil-fuel intensive processes and contributes strongly to global warming. You may want to consider if you want to support this industry.

How about putting a request out on your local freecycle or Craigslist for used wood? You might be able to get your materials for free!

For the bottom of the beds, you might consider sprinkling some blood meal or other organic source of nitrogen, then a layer of cardboard. Wet the cardboard, then sheet mulch into the raised bed: browns, greens, and manure. You can build the beds now and start composting now. Let worms do your work for you!

A 10-12 inch height for the sides is good, but be sure to heap the compost well above the top, as it will reduce to at least 1/2 the height as it decomposes. Boards of this height will also let you fit in pvc or metal hoops so that you can make a frame for visqueen plastic(if a coldframe is desired) or bird netting (if birds dig up your garden).

Wood is a lot easier to work with!

Just my 2 cents...

I made raised beds without sides. Just piled up on top of a compacted sand and gravel area of the yard, flattened the top, and slapped it all with a shovel (mostly compost). Because they have great drainage (raised, and LOTS of OM)- the water goes through without washing the raised bed away. Mulch (shredded leaves/hay) is really important here- but it's important if the beds are raised or not.

Wood ash and lime are only needed if you have low pH- very acid soil. I have acid soil and don't bother with it because my beds are mostly compost- not native soil. I don't know why people used to be so lime-happy.

Leaves will make a good bottom layer right on the grass. Try a lasagna bed. Honestly- you really don't need sides on it- I just keep piling the organic matter on top as mulch (shredded leaves, hay, bunny poop, coffee grounds) and it composts in place.

g'day Terrabeth,

can't help much with the concrete part of your question, if does sound like a lot of work though.

maybe have a look at how we do our raised beds we have pics and descriptions on our site 2 pages of it. might be some ideas there for you?

len

Here is a link that might be useful: len's garden page

Wood is expensive and always rots. Pressure treated wood and railroad ties are loaded with toxins. Plastic wood is very expensive. Large tractor tires with the sidewalls cut out get very hot and should be white-washed (search web for possible toxins). A concrete oval or circle 20' in circumference ( the length of pencil steel or rebar) will last indefinitely and cost little. Fresh concrete has to be protected from freezing for several days. You should line the bottom of your beds with hardware cloth if you have gophers.

I've used those concrete retaining wall stacking stones that you can buy at most big box building stores. I buy the limestone colored ones and they weather nicely, growing moss on their sides in shaded areas. And, you can easily stack them deep enough for deep raised beds, you can make rounded shapes and corners, and you can move them and reuse them if you change your mind.

No toxins, portable, readily available, durable. Think about it.

Got a friend that's trying to figure out how to get rid of the ones a prior tenant of his property installed. They were made way too wide and they're hell on a rototiller.

There are those occasions when people tear up their driveways or other concrete expanses they don't want to have baking in the sun near their house anymore. Or maybe they want to plant fruit trees and a garden there. The Eugene permaculture guild just had a discussion about the various methods most effective for removing driveways.
[An experienced person who lives at the Lost Valley Education Center outlined his preferred method entailing two people, one long pry bar, one 8 pound sledge. One person pries up with the bar and the other taps in the right spot on the tension curve, creating a crack and following that....]

Back to the matter of your raised beds, if someone does break up their driveway, you can use that refuse as blocks to build walls for your beds, (much in the way the person mentioned in a previous reply when suggesting the blocks to be purchased at a big box store). The cement will affect the ph to some degree, so you may want to balance for that around the edges of the bed.

Happy almost spring!
Jib

Thanks to all who've replied... I've learned a lot and am considering various factors, such as energy intensity of manufacturing concrete, longevity and toxicity (if treated) of wood, etc. I really enjoyed visiting Len's site and seeing the wonderfully descriptive images of the strawbale raised beds. I'd been hearing about them, but hadn't seen them. Now my interest is even more piqued, so I'll have to give a try to that, too, especially now that I've found a source of free city compost, as much as I need free for the shoveling. On another list, it was even mentioned that one could plant IN the strawbale border, too.

This year, I'm going to trust the recommendation that I don't actually need sides on the bed, and have laid down some lasagna style beds without sides, though not very high.

Again, all the responses much appreciated.

happy gardening,
Terrabeth

g'day terrabeth,

yes plant into the bales i did initially growing parseley's and mustards.

have fun and good hunting hey??

len

I have 7 raised beds. Four are made with wooden sides, 2 are plastic children's pools with holes made in the side near the bottom, 1 is surrounded by concrete blocks. ALL these materials were acquired free from friends, relatives, freecycle, and dumpster diving. Buying stuff for the garden, I hardly believe in that. :-) Seriously, I didn't even try very hard. I didn't ask for any of this stuff except one wooden bed (which was literally a bedframe that a friend was going to burn), I just took what people were offering.

I cannot use the just pile things up without a side method. I have super duper attack weeds here, they crawl under the sides of the raised bed walls as it is, if there were no barrier they would wreak even more havoc with my gardens. Also, it helps to keep stuff from rolling out while I create the lasagna beds (I get a lot of old fruit, which tends to be round and hence rolls.)

So although concrete sides might sound good and longlasting, why not try to make a raised bed out of something free? Compare that to the on the ground with no sides one and see what you think. Lots of advice about this topic in the soil, mulch, and compost forum. Good luck gardening! If you can get free compost you are already half way there.

Marcia

I experimented with building concrete sides for one of our raised bed gardens last year, and it was really a huge amount of work, not to mention expensive. In the end, I pulled the whole contraption down and went back to recycled wood borders. Yes, it rots, but there's always more wood people are tossing. Now our gardens are a mishmash of wood, broken concrete and used cinder block borders. Ugly when they're empty, but it's really pretty when they're spilling over with plants. I tuck trailing rosemaries and sedums into any spaces.

White-washed tires are great borders. Love 'em.

It seems like it would be a lot of work to make, a lot of invested energy, and that it would be really hard to undo when the next person on the site doesn't want it.

A good way to make raised garden beds is to measure and mark your bed, then dig out a foot of earth, make a pile... Accumulate extra wood, from twigs and chips to poles to logs and fill up the hole that you have dug. Then, on top of that put the earth back, mixed with compost if you have any. Over the course of years, depending on sizes of the wood, the decomposition of the wood helps the plants grow... and you have a raised garden bed

I have heard of these having increased fertility for as long as 20 years. After that, you'll never know it was there... -Ben

I've done a variety of raised beds and even a few sunken ones. We have very sandy soils and hot dry spring weather here so the "sunken" raised bed was supposed to help keep in moisture. I simply dug a trench, dumped in the free compost from our county and planted sunflowers. It worked very well as the sand from the trench mounded up around the sides a bit but by the end of the season, it was all flat again.

I think my favorite "fast" raised beds consisted of cardboard produce boxes filled with compost. They only last a season or two but I've come to believe that one should re-arange the garden often to keep up the diversity, soil building, crop rotation etc. When the bottoms rot out of the cardboard boxes you can then pull off the sides to use in the bottom of new raised beds. With the sides pulled off the boxes it is then easy to hoe around the old contents of the boxes to deal with the weeds that did get in and then build a new bed on top or cover with mulch and let it go fallow for a bit.

For more perminant plantings like perennial flower beds, I like rocks, concrete chunks and other such debris that can be kinda decorative borders for the plants. It is harder to control weeds in such borders though and you hate to have to re-do them too often.

Most of this season's raised beds are simply mounds built atop cardboard. The ones that didn't get the cardboard bottom, already have weeds in em.

By the way, Len's advice to put the paper products down around the planting beds with mulch on top would probably solve much of the aggressive weed problems as you have a buffer around the bed. Personally I would probably just make the bed bottom continous out a few feet past the planting bed area so there is no easy path up right at the bed boarder material (if used) I find that weeds really like to grow up right against border materials where it can be difficult to get them out intact.

I go with the idea of scrounging whatever you can from wherever you can. I frequently find bookcases on the side of the road during "curb shopping" expeditions - they're usually particle board with cheap lamination, and most often the back has fallen off, which is why they're being disposed of. Take those home, throw them down on the ground, fill them up with the soil mix of your choice. They look fairly neat. In a couple of years, of course, moisture will make the particle board fall apart; at this point, you can take the bed apart, peeling off the veneers and trashing those. Then you get a new bookcase, put the half-composted board at the bottom of it, refill with soil or lasagna layers or whatever, and start over. Or you can put the particle board some place near your compost bins where it can moulder away and be added as browns when it crumbles. Eventually it will be compost. (Particle board shouldn't be burned, but composting is a slow and safe way of dealing with it.) Don't go buying new ones for this purpose; but reducing the bookcase to a small wad of veneer and a bunch of organic material is much better than putting the whole thing in a landfill, IMO. Cabinet frames and old drawers do nicely, too, and provide varied heights for interesting design (and raising plants to comfortable levels).

Plain wood bookcases last longer if you can get them, but don't use painted ones - the paint flakes off and gets in the soil, and you have no way of knowing whether there's lead in there or not.

Plastic "milk crates" can be used to support cardboard boxes full of soil, or even brown paper bags. After harvest, dump all the used soil, complete with the crumbling remains of the paper, into a pile, refresh it with some compost, and put it into a new box. You can rearrange the boxes easily.

Plastic swimming pools with holes in the bottom are also good, as long as you don't mind the "blue with little fishies" look. If you do mind fishies, stack used bricks, stone or broken concrete around the pool to hide it.

You should never, ever have to pay for any of this stuff - plenty of people throw stuff away every day that can be repurposed and saved from the landfill, at least for a while.

A neighbor was replacing a patio , ( the 16" x 16" x 2" concrete paver) with a faux stone patio, so for the costs of loading and hauling away, I got my hands on 32 usable pavers.

Lee Valley sells a steel kit, which when coupled with timbers, allows these sort of pavers to form the sides of a raised bed.

I figured that a molded concrete cap and foot, would do the same thing, look better and be more permanent.

I built a simple U shaped mold, 128" long, 6 inches wide, with a 34" upright on each end forming the "U" shape out of used 2" x 8". I used 2 x 4"s for the sides and end of the mold, with a 2 x 4" ripped down to 2 x 2.5 running own the middle.

I poured fiber reinforced concrete into this mould and made 4 pieces to start.

Two pieces get placed with the U ends facing each other and the channel facing up. Ballancing the pavers was tricky, after several failures, I built a rough box out of scraps to keep the pavers from falling inwards, and used a cinch strap to keep them from falling outwards. Once the pavers were in place, two pieces were used to cap the pavers and lock them in place.

They look good, work well, heat up quickly in spring, but leaked water like a sieve.

Once I lined the sides with plastic before putting the caps on, they became much better at keeping the soil moist. I used a black UV stabilised 8 mil poly, which lasts for about 10 years before it degrades and needs to be recycled.

Instead of continuing with the plastic, I redid the forms allowing for a quarter inch gap between the pavers, and beds that I have built since then have had the gaps between the pavers mortared with a mix of 35% thin set, 65% regular brick mortar with some fibre reinforcing, that seems to work well.

I put the word out to several local landcape companies, and as a result, have a steady supply of pavers available, as otherwise, they would have to pay to haul them to the dump.

How is the experiment going? How are the sideless and bale raised beds doing for you?

I think I would only go to the trouble and $$ of pouring concrete sides for a raised bed if it was going to be for a wheelchair gardener. In which case an really heavy duty table covered in containers might be even more appropriate.

Currently almost all my gardening is in raised beds of some sort or other. Mostly sideless, some cardboard box/container garden types, and one with "sides".

Only one of them has really official "sides", it was 4 bits of plywood that were left over so I put em together and filled with lasagna layers and compost. I liked this for laying out some kinda square foot gardening type stuff. Easy to tack strings accross to mark out squares.

As for sides stopping weeds. I've always had trouble with weeds that come up right against borders, they are hard to pull. I suppose if the area of the raised beds is completely weed free before starting and then the area surrounding the bed is kept weed free then the sides would be ok. For my experience with aggressive running grasses, they are easier to pull when there are no sides for them to sneak under, once they get under a side and pop up in the bed, good luck getting a good enough grip to pull up a rhizome that is all nice and cozy under the side.

Anyway, I wouldn't want anything too permenint in my garden since I think it should be ever evolving and changing.