It looks like your post reads 375, but obviously you mean 37.5. Still you can build a raised bed without a hard border....I have several without that are fine. Course some people like the estetics of walls.

It looks like your post reads 375, but obviously you mean 37.5. Still you can build a raised bed without a hard border....I have several without that are fine. Course some people like the aestetics of walls.

Wayne,

I was talking about how many cinder blocks I'd need. The 375 came from 20'x5' = 50 linear feet or 600" of border. If one cinder block is 16" long, then I'd need approximately 375 cinder blocks.

This bed will go in the same part of the yard where my dogs are so I want hard borders that I can attach additional short fencing (small dogs) to keep them out. I do think I'd prefer the aesthetics with some kind of hard border because the rest of the back yard is heavily landscaped.

Thanks for the reply!

Brad

Brad,
I think Wayne is correct. For a 20' x 5 ' bed you need 50 linear feet for each layer of blocks. If each block is 16" (or 1 1/3') then you need 37.5 blocks. 50/1.33333 = 37.5.
Rick

You are absolutely correct!

However, math aside, my actual question remains.... are they worth the expense? Wayne doesn't use them but I was wondering if others have and find them worth the added expense. I believe they would "breathe" fairly well and should last a long time but replacing fairly cheap lumber would also not be that big of a deal.

I don't know what they actually cost but certainly, a factor of 10 would make a big difference.

If you are putting the raised bed of cement blocks together without mortar, you may need a border frame to hold the blocks in place--or you might set them slightly below grade to keep them in place. Mortar will increase the cost; setting them below grade will reduce the height. If you take the dimensions to the local home store or lumber yard, a person at the contractors' desk should be able to give you a cost estimate for each option. Compare the cement block (and frame of plastic edging or rebar stakes if needed) to the cost of untreated redwood or cedar (1 or 2 inches x 12 or 18 inches wide by the length you need). I have one raised bed of cement block three-feet high along a concrete walkway that is easily accessible to my elderly mother. It was much more expensive because of its height, and, of course, it is permanent. That bed is open below so that it easily drains. It dries out less quickly than my redwood sided raised beds.

Here is a link that might be useful: HarvestToTable.com

Our community garden is building more beds and I've priced a few things just so we could compare. We have 12" high beds that are 4' x 18-20'.

The eagle scout said a cedar bed would cost about $250.00 and a pressure treated bed is about $155.00. Since cinder blocks go for about $1.69 each here a bed made with them would be the cheapest.

Prices vary with location so I'd take your calculator and head to the home store.

The biggest problem with cinder blocks is keeping them together but a thick layer of mulch around them would probably help.

I made cinderblock beds and I love them. Not very pretty, but very functional. I got a pallet of cinderblocks delivered. Can't remember if it was 200 blocks or $200, lol, but I'll try to look it up tomorrow. In the meantime:

{{gwi:12838}}

You can see the reason for the raised beds (solid rock ledge) and that should tell you that they are NOT level. But I filled the holes with soil, which adds stability - and extra growing room!

:)
Dee

I built my raised beds from lumber that was free (posted on Craigslist). My garden beds had a previous life as a deck, well actually a couple different decks...

Just another option to consider...

Dee,

That's exactly what I was envisioning! Thanks! Are those mortared together or did the overlapping pattern of stacking them hold them together?

Shebear,

That's great info, too! I would have thought the cinder blocks would have been more but, as I said, I haven't yet put pencil to paper.

Thanks to all for the great feedback!

Brad

There are a lot of materials that can work and the best cost / benefit ratio will vary depending on where you live, the height needed, and how long you need the beds to last.

For cost, free materials almost always trump everything else. If you have to pay market price then the factors listed above should be considered.

Wood works better in climates that are cold because they last much longer. Warm areas promote rot year round and if termites are a problem, untreated wood can fail after a single season.

Standard concrete blocks work better in warm areas, don't rot and can be moved if necessary. Used one block high, they have good stability and are cost competitive with other materials.

Height of walls is a major cost factor. Where the native soil is good, a height of 6 to 8 inches may be all that is needed for good gardening. Where this is not the case and higher walls are needed, then the cost / benefit of both wood and blocks can be surpassed by poured concrete, especially in warm climates.

Where multiple beds are built to 12-16 inches, poured concrete is only a little more than cheap wood and less than expensive wood. It's permanent, stable in a way that blocks two high can never be, and can be finished to look good with almost any house.

if you only want 1 block high then you could get away without any edge at all. we have used many materials some was old roof metal from the demolition yard, that was as easy as to set up for beds and light to manhandle as well.

our latest started as hay/straw bale beds filled with mushroom compost, they are 3 years old now the bales have long since rotted, they are still there in their shape and form, and we have just added our weed barrier path around them.

our next step is to add corrugated roofing as the edges, to a depth of about 20"s, this for as we get older, but that all costs money and lots of extra mushy compost to fill them even with the material we already have in place.

len

Here is a link that might be useful: lens garden page

Gee Brad, I'm sorry, I can't seem to find my receipts. I'll keep looking. I ended up getting the pallet delivered because it was just taking too long to make all those trips to Home Depot for a few cinderblocks at a time.

No, my beds are not mortared. I alternated the blocks, and filled the holes with soil. You can see I have one one-level bed (way off to the left). This, IMO, looks better, and it works in that spot because the existing soil is a bit deeper. The two-level beds, I felt more comfortable having higher/deeper, because underneath is solid rock, and therefore I could make the soil level deeper. Again, not very nice-looking, but very functional.

I'm really happy with these beds and feel the cost was well worth it. Now, if I can only find what the cost was, I'll let you know. I have another folder I can dig through...

:)
Dee

Dee,

Please don't go to a lot of trouble... as has been said, it might be very different where I'm at. Thanks for your time!

Brad

I really love my unboarded and unblocked raised beds....cheap and extra versitle. They paralell each...no wasted space.

I have raised beds just like Dee's and I love them. Mine are stacked just like hers and I also filled the holes with soil. The top 6 inches in the holes are 50/50 compost and manure. I have herbs and ornamentals growing in the holes and cascading down the sides. I've grown some chard and onions in the holes too, and amazingly they do very well. I would have thought they would suffer (which is why I used 50/50) and dry out too quickly. I also live on very rocky/caliche soil and mine have been very stable so far. The oldest one is 3 years, I believe. I'm on a slope and they haven't gone anywhere. We did "dig" (more like use a pick ax) on the higher ends and build up the lower ends so that the beds would be level. Mine are not mortared but I consider them permanent. God knows I don't want to move them anywhere!

Like Dee said, it is a hassle with all the trips to Home Depot for the cinder blocks... which is why it is taking us so long to finish. But, I plan for mine to be pretty eventually, with the plants hanging down around them. We also made an arbor out of cedar branches and stuck in to the holes, then filled with pea gravel. It's amazingly stable and I use it to support climbing things, like cukes and malabar. When the arbor rots, we can just pull it out.

And, you will be able to keep the dogs out that way. Well, more than likely. I have Houdini the digger dog (70 pounds). Mine are two blocks high and for some reason she just stays out of them. My original intention was to fence it off, as well, but I haven't needed to yet.

I'm all for free or cheap, so if you aren't in a hurry you might check out Habitat for Humanity stores (I think also called Restores ) or try your local Freecycle. You can find some of the strangest stuff there! It's kinda like craigslist, but more localized IMHO.
All of my raised bed gardens have been constructed with free materials (except for the gopher wire) I have wood, cement blocks, brick and railroad ties. All look and work great! HTH Nancy