Cinder block raised bed

Hi all,

I have made 3 raised beds over the years, all of them by now transitioned to wood chips composted by Wine Cap mushrooms.  My original bed is now almost 3 years old measuring by age of wine caps and the fallen oak and hickory logs that make up the raised edges are over a decade old and are in rough shape (helped on by Wine Caps).

My other beds are raised with 2x10’s painted with dryloc, a masonry sealer safe for fungi yet protects the wood from the ravenous mushrooms.  They are all 8’x16’ and each needed a surprising amount of leveling even when laid on what appeared to be level ground.

The first bed raised with logs is about 6ish feet wide and 32’ long and the ground is plainly less level than the other beds.  

My big question:  how important/how much leveling would I have to do if I replaced those logs with cinder blocks?  I would use 2x10’s, but 16’ is the longest length I can get.  Also, the wood will eventually rot while cinder block will last essentially forever.  I know I could just lay the blocks on the surface and let them be, but I want them to be at least a little aesthetically pleasing.  Also, as the blocks are only 8” tall I am thinking about adding a second row and I would think that I would need the first row to be pretty level in order to get a second level in place.

So has anyone else tried a similar project?  I would love to hear your experience.  

Eric

Interesting, I am using boards now but can expect they will break down in time. But buying a lot of concret blocks is pretty costly too.   Wow then buying piece meal?  I have three 3 foot wide x 24 feet long beds, It would be nice to lay concret blocks maybe three high later.  I would only lay them on top of each other so may need rebar to support from pressure from bed.  Another fun idea one can plant in hole of concret blocks.

I have yet to land on a perfect corral for beds. I have a few cement blocks but don't like them and if you get true cinder blocks, the fly ash has toxic issues which I don't need on property. The good part is I have another couple of years before I really need to start building up as most of my beds started 2-2.5 feet below the ground surface. Each year a little settles, and I add more fill. I didn't want to use wood because it is a temporary fix (warping, decay, preservatives or not) and I hate to do stuff twice where it could have been just once. Who knows? If I'm lucky enough to get stone or brick, that might be the fix plus it will add to critter habitat. I went by a place where they were tearing down a housing area. They have all these concrete window sills. Those would have been awesome but a truck, some way to transport through the yard, and a few people would have been needed even if I could get permission. It kills me when I go by to see them being tossed into giant shredders/grinders to be put onto trucks and transported to the landfill.

Michael,

I understand your thoughts on wood.  I do expect my 2x10’s to last a while thanks to the dryloc (recommended to me by fellow Permie Bryant Redhawk), but they are not a permanent solution.  Maybe if I get lucky I will get a decade out of them?  Hopefully more.  But they are still temporary.

Echo,

I hear you about the lack of ideal garden corral.

All three of my beds started out raised by oak and hickory logs that fell in a really terrible storm.  The decision came down to burn them or use them for raised edges.  I won’t lie, tragically I burned a LOT of logs for disposal, but these were in my pre-Permies days and I had to do something with the logs so using at least some for raised beds seemed like a lot better option than just burning so I got some usage out of them.

But that was in 2009.  Those logs are in really rough shape now.  Some are being held together by my own wishful thinking.  I was going the cinder block route because believe it or not, it is actually cheaper than wood!  I compared the two prices and the 10” wood is more expensive than a cinder block.  Also, at 32’ length, I am sure the center of the bed will bow outward.  I am going to try to get this bed at least close to right angles this time.  My other two wooden beds actually look pretty good for now and I would like the third to match.  

I have laid down landscaping bricks before and leveled them, but it can be a tedious process.  I learned that the easiest way to do this was with dry cement as a base for leveling.  It does not take much, even just 1-2” is typically sufficient.  But at over 70’, this is a lot of leveling.

Eric

Here’s what I do for bigger raised beds.  I use straw.  It typically lasts 3 seasons.  1 bale high all around..3-4 on a side; 2-3 on an end.  When the bales deteriorate I cut the strings and pile all the matter ( moldy deteriorated hay) in the center of the bed or throw it on my other more permanent beds.  I mix everything around..shove it into a pile in the center of the old bed.....put new straw bales all around and then fill with my center pile.

I do corn, spuds and you name it and am constantly re vitalizing my bigger beds.  The only significant problem I have is that here I get wheat straw; so I always have a nice crop of wheat growing on the bales.

The second year the bales are soft enough I can plant right on the bales as well as in the soil within.

It’s a temporary permanent solution and it’s really quite pretty when it’s all growing. It helps to find a nice level spot.

My other beds are galvanized recycled stock tanks from when we raised cows.

I use sawdust more for the insulation value than aesthetics

I garden in the humidity of N. C , and even PT wood won't last 5 years before it  is mulch. That said , I have started to replace  all of my beds with CMUs ( cement blocks). I have attempted to use as many salvaged or used blocks as I am able to get ,but the quantities needed are large . I have replaced  6 4'x 8' beds with 2 4' x 24' CMU beds. My ground has some slope so they range from 24"  tall to 1 6" tall. At least 8 " is under grade to deter moles  and voles ( I have many) and to eliminate the dreaded witch grass, Bermuda grass or whatever you want to call it, from taking over the  beds, it overpowered  8" - 12" of wood chips mulch in the pathways in a little over a year and was a full time wedding nightmare in my beds. It even grew into the wood sides itself  to get in the garden beds. I chose to mortar my blocks because of the height. My son and I  built som CMU beds at his house in Maine  without mortar. They settle ed and moved a little in the winter but we're only 2 blocks high with most of the lower row underground. I would guess that you would be fine without mortar  as long as you carefuly   level the ground and put the first row slightly below grade . With out mortar you will  have some springtime realignment but should be fine if they're not too tall. Please check around for free or cheap used blocks as the concrete is not an environmentally friendly product

Looks good  vs. Affordable vs. Easy vs. Durability vs. Earth Friendly...
Those are a lot of trade-offs to balance.
I suggest you seek out used cinderblocks and resign yourself to the  hard work of leveling.

I expirement with all kinds of beds, but how they look  is dead last in importance to me.
Durability is also low on my list of important,  because building stuff over again doesn't bother me.

I do have a few ideas that might be cheaper or easier than cinderblocks and still look ok.
First, you are probably over building.
Thinner material works fine for holding back most soil, as long as its staked in place.
Cedar 2x's  are very expensive here, but a 1x6 cedar fencing is not too bad.
They are only 6' long, but the joints can be covered with a stake, which you will need anyway.
From a single board you can make 6 stakes, each about 2.25" wide and 2 foot long.
If your site isn't level, make some of them longer.
Rather than digging down, build the wall of the bed level , top of the wall down.
As each section  meets grade, you can rough cut a board to fit, much more easily than digging and leveling.
I've done this, using cedar stakes and surplus untreated 2x boards,to build my sisters 20 foot long bed.
It's about one foot high on one end and 24 on on the other, but its plumb, level and strait.


I get large tiles from a surplus place and I've used them to build a bed and a fence.
For your bed, I would use cedar stakes to hold them vertical.
At each joint, a sandwich of stake/tiles butted together/stake would be held together with deck screws driven between the two tiles.
Same as the cedar bed, but modified, so we don't have to drill holes through tiles.
I have built (most of) a 6 foot tall garden wall this way, though I used untreated 1x2s at each joint.

Ok William, just when I think I have my mind set on things you go and make me think I have been barking up the wrong tree.

So appearance is part of a happy marriage compromise.  Personally I was happy with logs.  But those are gone now and desperately need replacement.  My wife would like the bed to look better than the present one does and the other two do look pretty nice so for my wife’s sake I am going to try to make things match.  I am tempted to coat cinder blocks in the same dryloc that coats the other beds just to color-match.

At one time I was interested in cedar but was put off by the price.  I had not heard of the 1x6 cedar fencing.  You now have me officially intrigued.  I don’t suppose you have a picture for reference do you?

Thanks for a bit of perspective,

Eric

Logs certainly level more easily than blocks, but as long as the beds aren't really long, it isn't too hard to level them.  If you plan to make a lot, you can have somebody come in and level with a tractor bucket.  If it is just a few, I find that a grub hoe is the best tool for the job.

More about my experience with block beds here:
https://www.cultivariable.com/how-i-build-raised-beds/

I have used concrete blocks for raised beds for maybe 15 years.  Works great.  Note the term cinder block is very dated and was when the blocks were made by fly ask from coal power plants. Now they are made out of concrete. I don't think you will find a cinder block under 40 years old.  
Concrete block is quite safe and the dirt will settle in place eventually. I have found that I can remove the concrete blocks after 5 or 6 years after the root system is in place and the blocks can be used for another area.  For an annual bed they need to stay in place.

I don't have close up but here's a netting enclosed bed I made for my mom, and the cedar staked bed image for my sister.

William,

I like your “equation”.

Attractive+Affordable+Durable+Earth Friendly+Easy=Awesome Design.

Feel free to disagree or point out errors, but the way I am looking at this is that


Attractive=Necessary for wife

Durable=Affordable+Earth Friendly over time

Cinder blocks are probably not easy but done properly only need to be done once.

My 2x10’s painted with Dryloc were not cheap or particularly easy.  I was surprised how little things like connectors added up quickly.  And even with the Dryloc they are at best a medium term durability.

I do have a nice asset in that I have a neighbor who loves to help me out on these types of projects.  We used his heated shop to paint the 2x10’s in January.  I am sure he will be more than happy to give a hand in this project as well.  I am pretty fortunate there.

William, normally I would agree that I don’t mind rebuilding as I like building in the first place, but I am finding that the cost of rebuilding is adding up.  Too bad though as I like just about any excuse to get out the power tools.

Eric

William,

I was typing my last response and posted it just before I saw your pictures.  Do you know how long those 2x lumber last?

Eric

William W,

At present I do have logs, but they are finished and I have no replacement logs.  The logs were easy as I just dragged them in and dropped them roughly in place.  I did not bother leveling as neither the logs nor the ground were level.  The issue with cinder blocks is that they are short at a mere 16”.  The logs were 16’ in some cases.  I imagine this would make the cinder blocks look much less level if just laid on the surface.

Dennis,

You are absolutely correct.  I am using the term “cinder block” generically and I know that they are considered to be quite safe.  Actually, if I lay down just one layer of cinder (concrete) blocks, it actually cheaper than one level of 2x10.  Of course I may well put it 2 levels of blocks for a couple of reasons.  Firstly, the blocks are only 8” compared to 10”.  Secondly, the blocks are likely to be partially buried for leveling, so maybe I will ultimately end up with something like a 12” raised bed out of 2 levels.

Eric

Here's a link to the planking:Cedar Picket

It looks like Menards has 5.5" wide cedar deck boards (full 1" thick, not 3/4") for a tad over $2 per foot.  The fence pickets William is talking about are much cheaper at 5.5" by 5/8" thick by 6' for $3 ea.  

So 50 cents per foot for the thinner boards = more stakes/structure and less life before they rot through.

Either would be quite pretty and I love the idea of starting at the top with a level line and building the bed sides down until you hit grade or dig underground a tad.

If you're worried about the beds bowing out, you might be able to tie the sides together with some copper wire through the soil of the bed.  Or something equally non-toxic that won't rust/rot away.  

William, that really gives me something that I would have to think about.  I figure that including stakes the materials would cost about $90-$95 for two rows high (approximately equivalent to a 2x10).  I don’t know how long cedar will last, but I bet it beats my oak logs.

Thanks for that man,

Eric

I have quite a lot of terraced beds on hillsides, made with cinder blocks. I treat levelling as an ongoing project -- if something offends the eye, it's pretty easy to adjust.

One thought: we had a really wet summer, with a horrible and destructive invasion of slugs (hundreds, thousands). They really loved all the nooks and crannies in the cinder blocks as places to hide from the sun. Next spring I will be packing everything full of local sand.

A friend of mine replaced the rotted timbers around his raised beds with concrete
blocks a decade ago and is very pleased with the outcome. He is probably the best gardener I know.  He oriented the blocks with the holes facing up so he got some bonus planting space.

Eric Hanson wrote:William,

I was typing my last response and posted it just before I saw your pictures.  Do you know how long those 2x lumber last?

Eric

5 years, tops?
Every one of them was salvaged, either by me or I bought them for 50cents each.
No way I would have used them otherwise.
Long term, they should be replaced with cedar,  but short term they looked nice, which is important in greasing the wheels.
Now my sister and her husband have enjoyed onesummer of harvests, the hook has been set!
Going forward, I  do hope to line the beds with tile or even aluminum flashing.
The deck screws and cedar stakes will last a long time.
The 2x boards can be easily replaced.

For a long time I would just drive a row of metal stakes ,stack boards or logs against them, and hold the stack in place with more stakes or back fill.
The results were good, and easy to maintain,  but ugly for the wife, so bed creation at the house has become more difficult.

At my garden lot, where form follows function,  it  takes just 4 pallets and 12 deck screws to make a bed.
I used to cut the pallets in half, so two would be enough for a bed.
Since Ive found a reliable supply of pallets, its easier to screw 4 together and cut off the parts I don't want.
Excess wood is stacked under cover for future projects,  or firewood.





My wife also wants things to look nice, which would be fine, but we don't have a lot of cash.

People often line the walls of raised beds with a layer or two of landscape fabric. Apparently it gives the inside wood surface a chance to dry out, slowing rot.

We made some 1"x 6" cedar "stacking" frames using corners we bought years ago for 4'x8' beds. We used wire rope in the middle to stop them from bowing out. Eventually they rotted.

Two years ago I built a 4' x 8' concrete block bed with two layers of blocks. It had to be that width to fit some metal hoops I was loaned for holding up row cover, so I had to use some odd blocks to make the size work out. I realized very quickly that without leveling it reasonably well, I'd never be able to do two layers. I used mostly small rocks salvaged from digging other areas of the property because even though the area looked fairly level, it wasn't.

It was a huge amount of work. However, I'm *really* happy with it. I've got enough salvaged blocks to build another one, but once built, it will *not* be moved and there just isn't enough of a guarantee for me to do so until I have better fencing sorted out and firmer plans.

One thing I particularly like is that I can sit or kneel on the edge to reach in - this bed is built to never be walked on! You're planning 6' wide, so what is your plan for accessing the center?

Personally, I like shorter beds because they're quicker to walk around. Have you considered putting block "dividers" every 12 feet or so which you could use to walk across your bed? If you did this, the bed could be stepped every so many feet at the divider point, so you'd not have to be level the whole length in one go - just every 12 feet then a step up or down to accommodate the elevation gained or lost in the previous section. (Does that make sense?)

Jay,

I do like the idea of being able to use the cinder blocks for other construction, such as the base for a fence and gate system.

Eric

Douglas Alpenstock wrote:

One thought: we had a really wet summer, with a horrible and destructive invasion of slugs (hundreds, thousands). They really loved all the nooks and crannies in the cinder blocks as places to hide from the sun.

I read that beer traps atract slugs from an acre away and that placing the traps outside the garden will keep them from coming into the garden. I tried that last year and it seemed effective.

I was thinking of CMU's for my raised beds with a surface bonding coating on the inside and out. Menards has it for 16.00 a bag, that covers 50 sq. ft.. I think it's waterproof as it was used for making water tanks back in the wilderness, a long time ago.

I really like the idea of these diy concrete planter walls that interlink to make pretty much any size rectangular bed someone could want.  

In my opinion, way better looking than cinder block, can be customized with some creative thinking/art, will last just about forever.  I also like that the blocks mechanically attach to one another without having to permanently lock them together. I think cinder blocks would be more prone to moving/being pushed by the soil over time, but it's probably trivial.

Maybe someone is already selling these as a kit for DIY'ers.  I think it's a pretty cool diy project, but cinder blocks would be a lot easier to just go down and buy.  There's a bit of labor just to make the forms from wood.  Man, somebody really should just make the forms as a kit, and then sell them.  It'd be a lot easier.  

Maybe I've liked this video here before.  I know I was pretty impressed by it when I first watched it.

https://youtu.be/yuSBwFkCiAw

I think he experiments with perlite in the concrete mix, and other designs on his channel if it's of any interest to anyone.

Happy New Year!

Joshua Bertram wrote:I really like the idea of these diy concrete planter walls that interlink to make pretty much any size rectangular bed someone could want.

This would not remove the requirement of leveling the ground where the bed sits. In my experience, if they aren't put on level ground, they will not link properly. You'd either need a bunch of the molds, or it would be a fairly slow process to make enough for the bed described, but they do look very nice as a finished product.

We made the raised beds in my greenhouse out of a tiny fraction of the stones that my land is mostly composed of. Two different visiting foreign friends did the masonry while I just helped lug in the stones, and both friends were inexperienced, their first such projects. The one further away in the photo used mud mortar, and the one closer was without, but some of the stones rolled off in the first year, and water was running out, so recently we mortared it with mud.

Burl Smith wrote:I read that beer traps atract slugs from an acre away and that placing the traps outside the garden will keep them from coming into the garden. I tried that last year and it seemed effective.

I've tried that, but have better luck with half-rotted, water soaked boards set down in the garden. They like to crawl under those during the day. And then I come along with a sharp knife in my hand and murther in my eye. But this year was a freak year, with slugs crawling in from the woods and everywhere. DW and I must have killed a thousand of them directly. Nasty business.

(End of thread hijack.)

Sorry made a mistake meant concrete blocks NOT cinder blocks.

Eric, I think it's mostly a matter of what you like.  I'm kind of a use what I got kind of person, so I have many different materials for my raised beds.  To be honest the double concrete is my favorite.  I dug down a couple of feet and placed concrete block around the hole I dug, two high.  I filled it hugel beet style.  I love it, it is so much easier to work on.  Honestly I didn't level it except enough to keep it from having any large gaps.  I started out using weed cloth to keep the weeds out and the soil in.  I didn't use it this last time, and didn't notice any soil escaping.  I did lots of research, and considering my blocks are super heavy I think they are made with concrete, and not cinderblocks.  I guess there can be a problem with lime leaching into the soil, but if this is the case, I haven't noticed it. What I like about using concrete blocks is they are cheap and last a very long time.  They don't have to be ugly.  You can paint them, or plant something around them.  I didn't bother, because my eye is always drawn to what is in the bed, and I don't think I have ever thought that is ugly.  You also have options as to how you put them together.  I have made a star shape, flower shape by putting the blocks together corner to corner instead of edge to edge.  I don't have one like that at the moment, but I like the way it looked, and never had any problem with them coming apart.
An other bed is also a hugel beet and dug deeper because I didn't have enough blocks to do a double wall, so it is only one block high.  It works just as well, just lower to the ground.  I don't know about others, but I tried to grow things in the holes as bonus space, and never could keep anything alive.  Maybe because the California sun makes it too hot and or dry?  The one block system shows even more garden and less block if you find them unsightly.
I built a raised bed for my flowers 3 years ago out of cedar fence posts I got on clearance at Home Depot because they had some cracks and some weren't straight.  The hole project cost me less then 10.00.  I spray painted the outside to help it last longer, and because I had it, so it didn't add to the cost.  I also lined it with weed cloth so I didn't need to worry about soil escaping through the knot holes and gaps.  I love it and it seems to be holding up well. (I took a picture, but am embarrassed to share it.  With my husbands health problems, the holidays, and just general laziness, I'm so very behind on all my fall and winter projects.)
I also have two 4'X4' raised beds that I got on clearance several years ago.  I didn't like them because they were only about 6" deep and that just wasn't deep enough, so I bought the cedar fence boards and added them to the top of the raised bed, and it worked so much better, and has lasted several years.  
Last my niece was taking a wooden twin bed frame to the dump.  I asked her if I could have it and unpainted and untreated it lasted about 5 years.  It finally fell apart this year.  I will replace it with concrete blocks mostly because that is what my son got me for Christmas, but I'm not sorry I used it.  It was a perfect size, free and kept it out of the land fill.  Basically you can make anything work.  The cement blocks will out last all options.  Good luck to you, what ever you decide will be great, because lets be honest its really about what is inside that matters the most.  Happy Gardening.

I have used concrete blocks & 4x4's  to make raised beds in the past. Want to be thrifty and I love to repurpose, so I was looking at these really strong cardboard boxes that many of our shipped items have come in; thought wouldn't that work for a raised bed? I can fill them with mulch, compost & soil and the cardboard will eventually compost too!  I suppose the sides will deteriorate during rainy weather, so I have to think that one out. Any thoughts out there? Love these boards for learning and just being part of something wonderful!

Paul I think even a strong box will fail before the first growing season is up.  Water isn't kind to cardboard.  If you want to use them you could dig a hole in the ground and put the box in the hole. Maybe have the box and inch or two out of the ground .  This should keep the weeds out, and the support of the soil around the box will keep it together.  I like to use cardboard on my paths with wood chips on top, it works great. Good luck to you.

Janet Reed wrote:Here’s what I do for bigger raised beds.  I use straw.  It typically lasts 3 seasons.  1 bale high all around..3-4 on a side; 2-3 on an end.  When the bales deteriorate I cut the strings and pile all the matter ( moldy deteriorated hay) in the center of the bed or throw it on my other more permanent beds.  I mix everything around..shove it into a pile in the center of the old bed.....put new straw bales all around and then fill with my center pile.

I do corn, spuds and you name it and am constantly re vitalizing my bigger beds.  The only significant problem I have is that here I get wheat straw; so I always have a nice crop of wheat growing on the bales.

The second year the bales are soft enough I can plant right on the bales as well as in the soil within.

It’s a temporary permanent solution and it’s really quite pretty when it’s all growing. It helps to find a nice level spot.

My other beds are galvanized recycled stock tanks from when we raised cows.

I second straw bales Janet! Turns a problem (decomposition of edging material) into a solution (wonderful mulch), nice to sit on until they’re ready for their second use (mulching the bed they’ve been previously edging) and also they provide wonderful worm habitat for your free range worms!

I also think they look nice :)

Burl Smith wrote:

Douglas Alpenstock wrote:

One thought: we had a really wet summer, with a horrible and destructive invasion of slugs (hundreds, thousands). They really loved all the nooks and crannies in the cinder blocks as places to hide from the sun.

I read that beer traps atract slugs from an acre away and that placing the traps outside the garden will keep them from coming into the garden. I tried that last year and it seemed effective.

I thought it worked too when I saw some laying in the dishes. Then, I saw the time-lapse YouTube videos where most simply crawl away after drinking beer...much like humans.

Joshua Bertram - I made some of those concrete panels.  Was fun building the molds. I modified them to be 12 inches tall and 4 foot long.  They weigh around 40 lbs each.  I also found a rubber stair tread to make patterns on the side.
I made the holes large enough to put metal conduit inside so I can make a roof of mesh or shade cloth.

Dennis Bangham wrote:Joshua Bertram - I made some of those concrete panels.  Was fun building the molds. I modified them to be 12 inches tall and 4 foot long.  They weigh around 40 lbs each.  I also found a rubber stair tread to make patterns on the side.
I made the holes large enough to put metal conduit inside so I can make a roof of mesh or shade cloth.

I love it, what a great idea, and very pretty.  How much does it cost you to make each panel?  

It is not expensive. I did 10 panels with 2 bags of portland cement, Some perlite and expanded shale I had (50/50) and sand. Since it is cold I had to pre-heat the water to 50F and I also made a soaking bath (heated to 50F) with hydrated lime to make them stronger. The rubber mats were $25 for 4.