Raised Bed Materials

Hi!
I'd like to build raised beds this season and am looking for affordable options. We definitely can't afford cedar, and there is a lot of conflicting information online about the safety of cement blocks. What do you recommend? I'm really hoping to hear that cement blocks are fine--they are so affordable! Thank you in advance for your expertise.

Lynn,

I can’t see any reason not to use cinder blocks.  The are about as permanent an edge you can possibly find.  I know a lot of people like to use cinder blocks.

Go for it!

Eric

We have used cinder blocks and pallet wood (with the HT marking).  After researching cinder blocks (yes, there's conflicting information.... just like all topics), we decided that using the cinder blocks would be better than buying conventional food.  

Lynn,

I have heard of plenty of people who use cinder blocks for raised edges, but never heard of any danger.  So what exactly is the issue with cinder blocks?

Eric

I believe the term cinder blocks is dated and from a time when they were made of cinders (Fly Ash) from power plants.  Now they are made from concrete.  They do leach lime but after while it is gone.
Most it will do is raise the pH for a while.  
I use them for several years and until the raised bed is stable and a firm little mound and then move them to another area. Rinse, repeat.

Thanks Dennis

I've built a number of raised beds just using  2 x 10 doug fir from Home Depot.  But I'll always prime and paint the boards with at least 3 coats of paint first --- all sides -- to protect from moisture and fungal rot.  They last 10 years before they break down and fall apart.

Home Depot and Lowes often have an "Opps Paint" shelf where they have mis-colored paint for sale.  You can buy a 5 gal. pail of high quality porch and deck paint for less than $50 -- more paint that you'll know what to do with.  I buy that stuff and then paint three thick coats onto the raw wood.  It also looks nicer that way.  If you don't like the color of the opps paint, sometime if business is slow, you can convince the guy behind the paint counter to mix it to a darker color.  Brown is nice for a raised bed.  They'll say, "I can't tell you what color it's going to turn out."  Of course not -- but if you're mixing it to be dark brown, it's not going to be anything too funky.

As for concrete blocks, there's nothing toxic about a little lime leaching out.  It may raise your pH a little, but not enough to make any difference.  How many decades does a concrete sidewalk or driveway sit there, and it doesn't do any harm to the soil that surrounds it.

I've watched hundreds of hours of John Kohler's videos (Growing Your Greens youtube channel), and he is extremely careful about his food and grows a lot of his own in concrete block raised beds.  He's brought up the topic before, and he has a great philosophy/attitude when it comes to things.  There's always a "good", "better", or "best" way to grow your food (it actually applies a lot to life in general).  
If plastic five gallon pots is the best you can do, do it, because it's still probably better than what you're able to buy at the store.  
If concrete blocks is what will work best for you (maybe you've got access to hundreds of free blocks?) then that'll be great, and it'll still be better than what you could buy at the store.  
If you have the money to have a scientist come in, test for the best possible materials for building a raised bed in your area, have them test all the soil and compost and other inputs that go into that soil, and then buy a reverse osmosis system so that your water is the absolute most pure.....then that's awesome, and if it's worth it go for it!  Most people aren't going to go that far, but why not if it's worth it to them.

Obviously common sense says don't use anything that had toxic waste on it........for example, I just got 50 railroad ties for $20 total from the nursery I work for.  They were old, and had been used a while, but would have made great planter boxes.  After storing them on the side of my house for a week, the toxic odor coming off of them made me reconsider, and I sold the lot for $100 the next day.  Still, though, people have been using them in their gardens for years, and if that's the best you can do.......it's still (probably) better than what's available at the store.  

I decided I wanted better, so I'm currently in the process of building raised beds from cheap pine 2x4's, and galvanized tin roofing sheets.  I'm sure the galvanized tin isn't the best thing as it breaks down, but for me, it was what I thought was best for my situation.  Not the best possible thing, just the best for my current financial situation, and I like the overall look of them as well.

Oh yeah, I think I originally saw this link on permies.

If I had the time, I'd LOVE to have these concrete blocks for my raised beds.   He's got a bunch of videos out, now he's making lightweight concrete boxes with perlite and aircrete.

Here's his original, awesome design.  Diy concrete block garden beds.

Depending on the location of your raised bed, you may want to consider a lower profile, low cost, concrete option. For my courtyard garden I built a raised bed using 12" tall by 144" long concrete siding (Hardie board). Using 3' long green metal stakes placed in corners and every ~36" the 8" of soil is well supported. The cost of a 12' x 4' bed (48 sq ft with 14 stakes and screws) was $60 (2 years ago). The concrete siding is at the surface of the soil so the bed height is 12". The system is holding up very well as it enters its 3rd season. This project was lightweight enough for me (50's female) to transport materials in and on a mid-size car and build the garden in a weekend. The key is that each side of the rectangle must be solidly staked on its own and the Hardie board secured with screw (outside) and bolt (inside). This was a very satisfying project.
Good luck with your build.
Amy

S,

Those are AMAZING garden bed edges! I might consider some of those for myself.

Eric

The most affordable cedar boards near me are of cuts from sawmills.
I was only able to find them once, but it was a great deal.
The cedar picket fence boards at Home Depot are the cheapest regular source I have found.
Ten boards could line a 12'x3'x1' bed.
At $2.97 each thats about 30 bucks a bed.
Maybe buy two more for making stakes,  plus some for fastener, so at least $40.00 before taxes.
By contrast, a single wall of block 12' longx 1.25' (16") high,  would cost about $27.00 if you bought the blocks new for $1.50 each.
Of course,  the blocks can be found used for less, or evenfree.
I  have only used the Home Depot boards for beds I build at my moms house.
To my wife's chagrin, I just use any darn untreated board at our house.
They break down,  but I just replace them.
I don't generally  join the corners,  instead I just drive stakes on either side of each wall.
This makes it easy to replace them.

I'm considering upgrading my game by utilizing large tiles.
I can get 1'x2' tiles  for 2 bucks each.
Six to a side, 1.5 for each end,30 bucks  to skin a 12'x 3' bed.
Stakes might be made of cedar,  rebar or metal conduit, fastened with deck screws,  stainless steel wire,  or self tapping roofing screws.
It depends on what I already have on hand.
I might even get 2'x2' tiles for the same price.
I prefer a deeper bed anyway.
Lining a bed made of treated wood with tiles could extend the life of the wood indefinitely.
Better than plastic in many ways.

Something not discussed is fencing as the wall of a bed.
Wire netting or plastic netting of all kinds can make the sides of a bed.
Smaller sized netting is better,  but any size can work,  especially when making a lasagna bed.
It's not cute looking, and it but it can work really well.
I would like to try stucco over mesh fencing to make it more durable and pleasing to the eye, but I can I justify the labor and materials when I have so many other  cheap and easy methods to try?
I will get to it eventually .

Someone mentioned buckets.
Buckets can be filled with soil, punctured for drainage and used as the sides of raised beds.
Each bucket is about a foot across, so 26 of them would enclose a 12'x3' bed.
Or,  use one bucket  at each corner and affix your boards to them.
Barrels are about 2' across,  so two if them at either end of an bed might do.
Of course, two barrels, cut in half can make planting space roughly equivalent to a bed 17" tall,  x 2'wide x 8" long.
Poke drain holes or cut the bottoms out entirely, as you wish.
Screw vertical lengths of pallet board to the sides for looks.

William,

I like your very practical approach.  I am using 2x10 lumber painted with masonry sealer.  So far it is standing up to the elements but I don’t know how long that will last.

I like the idea of cinder blocks but they are not the most aesthetically pleasing.  If I went that route I would want to cap the tops so I could easily sit along the sides.

Nice post,

Eric

Here's a video I made of the type of raised beds I use. They're free and don't require any building materials, just some digging.

Masonry sealer on wood us a new idea for me,  I like it.
Do you coat all of each board,  or just the inside of the whole bed.

Thank you all for the great ideas and encouragement!! I'll probably be incorporating several of your thrifty, successful plans. Have a great week!

I like to use cedar fence pickets.  I stack them two tall and make the beds 4'x6'.  I buy the 6' cedar pickets and the ones I cut down to 4', I rip the 2' excess into pieces that can be used to secure the corners and add support on the sides of the bed.  Here is the basic plan I use and adjust to the size I want: https://ana-white.com/woodworking-projects/10-cedar-raised-garden-beds

I saw someone use garage door panels to make raised beds which I though was pretty brilliant.  They went to a local installer and asked for the old garage doors they removed and bolted them together into beds.  Seems pretty smart since they are steel and won't rot!

In my area (midwest) if you buy untreated construction lumber in a 2x12 size or larger it's made of yellow pine rather than the softer pines, spruce or fir. The yellow pine seems to hold up really well, though it does break down eventually (all wood will) you should get several years out of it for a low price and the end product is a composted board that you can easily incorporate into the bed and add a new one. We've had several beds of those up for 3 years now and still holding up.

I've also used logs (round ready to cut for firewood) set upright. They last a really long time and will decompose nicely in place as well.

J Vos wrote:I like to use cedar fence pickets.  

Amazingly, some people toss these in their trash.  I scoop up all I see for various projects; but I hadn't thought along these lines.  J, you have inspired me.

We built ours from clay, sand and soil from our own property. Net cost of the foundation (stone), walls (cob), and filler (wood, chips, sawdust, fungus, compost, and dirt) was zero dollars.
The labour, however, was onerous. It took me and a few WWOOFers about 6 weeks.
The results have been amazing. our potato and carrot storage crops tripled, and our fresh been crop was almost 4 times more productive.

I'm a big fan of cement siding, a.k.a. Hardie Backing or Hardie Board. You can often find it for free but if you have to buy it new, it's cheaper than wood. There's a thread with a picture here.

https://permies.com/t/211746/Raised-garden-beds-scrap-cement

The only downside might be, you can't have spans longer than 3 feet or so. You would need some supports for longer spans or I think it would crack.