building raised beds

[epiphanista]

Such great info here! Thanks dice, for your thoughts on the cement block issue.

I have only tried amending the 'soil' here once, and without a jackhammer and simply taking the clay away, it is impossible to garden in it. This is the stuff the Spanish made presidio walls out of, for goodness sake! Since I am in a different home this year, I am starting over with new beds, new soil, etc. This thread has been very helpful with ideas!

~Thalia

[Patapsco Mike]

Cement blocks do not need to be mortared together. They are heavy enough to hold any shape even if you leave the holes empty and you pile the soil very high. Because of their shape and the way they are designed, no soil will escape from the bed at all so long as they are fairly level.

Not adding mortar gives you the option to change bed size and shape each year.

I learned the hard way how important it is to line the bottom of the bed with landscaping fabric (or another impervious layer). I have never seen such healthy weeds...

[Worth1]

I think we may have had the worlds largest raised bed when I was a young sprout.
It was a big commercial chicken house we tore down and left the concrete foundation for a border.

I ran a subsoiler and plow in the place to break up the soil and then tilled in cow flop and decomposed sawdust.
The first year it was a little high on the N side but after that it turned out great.

We grew semi dwarf peach and apple trees in it and they did well also.

Worth

[epiphanista]

Thanks, Mike - I'd certainly rather not mortar if I don't have to. And I'll look into a fabric at the bottom of the bed. Much appreciated!

~Thalia

[tomatoguy]

I didn't use any mortar on my blocks, either. I did fill in the holes in the blocks with dirt which probably adds stability and the holes can be used to plant flowers as well. I did not cover the bottom with landscape fabric. My raised bed is 20 inches deep, though, and that may be why I haven't seen any weeds coming up from the bottom.

mater

[dice]

I used multiple layers of newspaper across the bottom
of one that I built last year, weighed down with compost
and horse manure until I got the bed filled up. (I used thin,
wide sheets of scrap wood from a milled fir tree for the sides,
staked in place; it will rot pretty fast, but by the time it does
I will have something else recycled to replace it with.) It had
fairly tough turf under it, some kind of wild bent grass
that sprouts up around here at random and grows in anything,
the kind of grass that you find in cracks in the sidewalk
and so on. The grass grew out around the edges at the bottom
of the sides, but none of it came up through the newspaper
in the bottom of the raised bed.

If you eventually find a wall of loose concrete blocks
annoying (after running into them with a tiller or similar)
but do not want to mortar the whole thing together,
for whatever reason, you can always just mortar the corners
of the blocks, basically tacking them in place with small dabs
of mortar. They can then be taken apart for disassembly
at a later time with a few taps of a sledge hammer and one
of those short, wide mason's chisels.

[robin303]

Originally Posted by epiphanista

Thanks, Mike - I'd certainly rather not mortar if I don't have to. And I'll look into a fabric at the bottom of the bed. Much appreciated!

~Thalia

Use about 20 layers of newspaper. Samething. Free. Simple.

[dice]

One other thing about lining the bottom of the raised bed:
that grass that failed to come up through the newspaper
in the bottom of mine has always managed to grow right
through landscape fabric, including commercial landscape
grade landscape fabrics that I had spread around rhodendrons
and azaleas and then covered with bark.

(The newspaper is probably all chewed up by worms and
decayed to humus by now, though, so we will see what
happens this year.)

[epiphanista]

Use about 20 layers of newspaper. Samething. Free. Simple.

I like free! Newspaper, it is. Great ideas, guys.

~Thalia

[bully]

Here are my raised beds

tulips in the Spring and tomatoes all Summer

[ferger1]

Boy! They really look great!

[dice]

A document on earthworm culture that I read mentioned
that another way to waterproof wood is to coat it with
paraffin. This was for the inside of a wood wormbin,
and paraffin was recommended because it was considered
safer for the worms than other water-proofing compounds
available at the time.

It would probably work on the inside of wood sides of raised
beds, too, at least slowing down rot. You probably want to
leave the outside uncoated (or just painted with regular
latex) so that the wood can dry out when it is not raining.

For anyone that has not worked with paraffin before, you
melt it in a double boiler and then paint it on with a brush.

Painting it on the inside with swimming pool paint
("elastomeric" paint) might work, too.

[robin303]

Very nice Bully. I like.

[dice]

[re: wood sides]
At some point you have to ask yourself when it is cheaper
to just replace the wood when it rots than to try to keep
it from rotting at all, too (remembering what I paid once
for 5 gallons of elastomeric paint; it goes on thick, so you
use it up faster than regular latex or alkyd paints).

[tumbleweed]

Hey Bully - like those beds. What kind of cages are you using?