Making a 4 X 4 Concrete Raised Bed - First Try

Many years ago, our dear neighbour, Ken, gave us the forms he'd made up for pouring concrete raised beds.  By the time we'd made 6 beds, the forms had seen their best days, but there was still some life in them so we passed them on to friends.  Ken's ingenious plan used long, thin boards, joined by metal corner pieces and kept in true with metal snap ties which had been cut down for the purpose and joined the inside to the outside.  U-shaped pieces over the tops kept the sides from bowing out when the concrete was poured.  These forms produced beds with an inside measurement of  3.5' wide by 14' long and with 4" thick walls.  Since there are cedar trees nearby, drainage pipes were installed under the sides and then concrete bottoms were poured to keep out the invasive roots.  This is what we've been gardening successfully in ever since.

Ken's concrete raised bed forms

We now have a little more room on the plateau since my husband pulled out the black currant bushes.  We never got enough currants to do much with - the birds were well fed!  The space provided isn't big enough for Ken's forms, but my husband thought there'd be room for a few 4'x4' beds (again, inside measurement).  Since we had quite a bit of fir milled from trees on our own property that now had powder post beetle in it, he used this wood to make the forms.  It's not good for anything else but firewood now!

Forms ready for filling

The pour went well - we used 5 wheelbarrow loads to fill the sides.  Since the lumber used was 2x6 and the sides 4' long, we didn't need all the strengthening material in the sides.  The bottom would be poured later.

Almost filled

The problem arose when my husband went to take off the forms.  We'd had lots of rain on the forms after the pour and the wood swelled.  The outside boards came off easily - the inside ones not so much! A few chips resulted from the effort of prying loose the inside boards.

Forms off - just the bottom to pour

My husband plans to make different forms for his next attempt and will use 3/4" plywood for the sides this time joined by metal L-brackets.  When we pour the next bed, we'll finish the bottom of the first one.  We're hoping to be able to fit in 4 of these new beds.  We also plan on making a portable cold frame top that we can move from bed to bed.  This will help extend our growing season.