cheap way of creating raised beds?

 
hello all, had such an epic day yesterday up at the soul patch but was
going to see if anyone had any canny and most importantly cheap ideas of
how to create large raised beds. i am thinking 2 20ftx10ft beds so quite
a lot of material needed. any thoughts well appreciated!




--
The Soul Patch

 On Sun, 16 Oct 2011 12:44:52 +0000, The Soul Patch


That configuration negates the most important aspect of typical raised
beds, being able to reach every part without climbing in... if you
have to climb up into your structure it isn't really a raised bed now
is it... you then may as well make one 20' X 20' bed and use less
materials.

I'd make them sized so that you can reach in to the entire area
without climbing in and so that they use common dimensional building
materials.  Don't think too much about low cost at the expense of
quality... the cheap always comes out expensive... there is no point
to building something if it will collapse even before the first
season.  Something important to consider is to build your raised beds
so that it bars small tunneling critters, otherwise it's all for
nothing... they will come.  Large critters are easy to deter, the
small critters require special efforts.  

I used real RR ties (used) but I lined the entire interior with
aluminum flashing that extends a good ten inches below the baseline
surface, it keeps tunneling critters out plus prevents leaching from
treated lumber... also helps tie all the RR ties together especially
the corners.  It was easy to add the flashing later when I discovered
the small critters coming to my salad bar.  I built my bed one RR tie
high, (~12"), works for me.  Mine isn't a typical raised bed, it's a
raised vegetable garden that I go into... the border serves to prevent
my good amended soil from washing away from heavy rains plus makes it
much easier to keep critters, both large and small, out... also deters
weeds from creeping in, and it was easy to attach a deer fence to the
ties, you may not need such.  Mine is 50' X 50', you probably don't
want something so large but the same construction would work for any
size.

 On 10/16/11 5:44 AM, The Soul Patch wrote:

Till the ground to the same depth that the raised bed will be above the
natural level.  That is, if the raised bed will be 1 foot high, till to
a depth of 1 ft.  While tilling, add bone meal or superphosphate;
phosphorus does not readily dissolve and so must be placed where roots
will find it.  Also add some organic matter (e.g.: peat moss, compost)
but not much; until you frame the bed, you do not want to raise the soil
level significantly.

Choose framing materials (e.g.: old railroad crossties, concrete
(cinder) blocks, 2x12 boards).  Your choice should balance cost versus
how long you plan to maintain the bed.  Also, your choice might depend
on whether or not you are planning "organic" gardening since some
framing materials are chemically treated to resist rot.

Frame the bed.  For a bed 20x10, you will want to anchor the framing
material even if you frame with something heavy such as a single course
of concrete blocks.  I would not use wooden stakes.  Instead, consider
scrap water pipes or steel rebar.  You should use lengths at least twice
as long as the frame will be high.  Pound the anchors into the ground so
that the top of each is about 1 inch below the top of the frame; this is
to reduce the risk of tripping on the anchor.

When the bed is framed, pile enough soild amendment inside the frame to
about 2-3 inches higher than the frame.  Till this into the top half of
what you already tilled.  Mixed with your native soil, this will quickly
settle down to the level of the frame.

Plant.

No, I have not recommended specific framing materials or soil
amendments.  I do not know what is available in your area or -- for what
is available -- what the costs are.

--
David E. Ross
Climate:  California Mediterranean, see
<http://www.rossde.com/garden/climate.html>
Gardening diary at <http://www.rossde.com/garden/diary>

 The Soul Patch wrote:

Why on earth would you make them 10ft wide?  They should be no wider than
you can reach into the centre without standing on the bed, usually 3 to 4
ft.  This will have a longer perimeter for the same area and so cost more
than 10ft wide but you don't want to walk or have to push a barrow over your
bed.

New materials like concrete blocks or timber that is durable in contact with
the soil tends to be expensive.  If you can get such second-hand you may
save much.

Corrugated iron (eg colorbond) is cheaper and works well but has the
disadvantage that you cannot sit on it.  You will still need to put an
edging strip along the top all the same for safety.

How high do they have to be?  If only short maybe no sides are required.
Where will you get the soil to fill them?

David

 
I would like to try this, as I'm tired of the Mickey Mouse job I did
of raised beds.

But I don't understand how sloped sides can maintain their shape.
Doesn't rain, or even watering, break down those sloped sides?

TIA

HB