Raised Beds

Make sure they're no more than 4' (1.25m) wide so that you can reach the middle. I made mine 4.8m (16') long, and a metre (3') apart. Easy to get to, and the plants which spread sideways don't block passage through between beds. I used 200mm x 50mm (8" x 2") boards all round, two high, made of pressure treated wood. They've been in place for over five years, and still going strong.

Goldie, i'll get the links tomorrow for you.
We actually like the galvanized pre-made containers for introducing/preparing them to retirement homes as incentives to get folks back into the soil without bending their backs.
But if you're doing yourself , cedar is best choice, concrete patio slabs is fine too. Check out Lee Valley Tools selection , or copy with your own components. I usually line the cavity with landscape fabric to help retain the soil from gradually seeping thru the joints. Also, i install a length of 4" "big O with a sock" at the bottom , for positive drainage with gravel over it , followed by landscape fabric and sand to keep the soil from eventually clogging the gravel.
I did this 25 yrs ago, and worked well, but i didnt have the time to secure the slabs positioning from frost heaving adequately.

A totally different approach is a "Hugelbed" ....creating a semi-terraced mound of at least 6' length, using deadwood, trunks, stumps, branches as a base, and adding soil which is basically held in place by these . Fot he first season, it is helpful to sow grasses and clovers whose rootsytems will knit the surface intact, and when it has all settled you can plant it full of a mixture of crops at different levels, as the carbon decays , providing warmth and collaborative microlife.

If you grow carrots in pure, raised beds you will have to monitor the moisture closely, but yes, you can get a good volume without bending.

We've used pretty much everything. Boards tend to go faster than timbers of the same treatment. Stone/block is heavier and sometimes more costly initially but lasts longer and is easier to build upwards later if wanted. You can also use wooden pallets (heat treated) chopped down to 1/3 or 1/2 height and filled with gravel or straw or sand, lined or unlined, and leave yourself room for either some earth or reused cans snugged into the center that can be planted with small lettuces, small cabbages, herbs, or strawberries.

We've started re-lining some of my mother's raised beds with cinder blocks to contain crumbling wood and making her new beds out of the same because they leave holes for things like chives or strawberries spaced around or along the sides.

There are also free-form lasagna beds and Eden Garden/mulch-top beds, or either type can be contained for a neater, more manicured look.

You can also do your potatoes in bags or large trash cans, which enables you to dump them over a tarp for harvest, no skewering spuds. Then you can just add in some compost and refill the tall containers.

Part of the thing for you will just be non-compacted earth, so what you use to fill or make the beds will be more important than what you use to make them.

We built raised beds out of Australian hardwood...obviously only available in Australia 😉
The timber is 100mm x 200mm stacked two high so the beds are 400mm high.
The beds vary in size 2mx2m, 2mx4m, 2mx6m with 1m pathways so a wheelbarrow moves easily down the rows and you can reach the center of the beds from either side.
We sat the timbers on top of the pavers and joined the corners with sheet metal bent and screwed into place. This makes it easy to replace any timbers easily in years to come. These photos were from when it was being constructed.

We have been using these garden beds for eight years now and the timber has greyed over the years but is still in really good condition and I expect to get a lot more years out of it before I will need to replace any of the timbers.

I am thinking of building some smaller 1mx1m beds that can be stacked to 1m high to grow potatoes in next year and also some 1mx1mx400mm beds to grow sweet potato. The sweet potato didn't do so well this year because I grew them in a large bed and never cut back the leaves so I ended up with really small tubers and lots of leaf growth, so next year I will give them a hair cut every time the leaves trail over the side of their allocated 1mx1m beds 😉

Treated timbers should be avoided as the chemicals leach into the soil.

That's enough out of me...I chew peoples ears off about gardening 😆

I understand that pressure treated wood is not good for vegetable gardens. So that is why I need to know
what type of wood to use . I also heard cedar was not good . Both leaching into the soil

I guess my raised bed idea is more a border for gardens where the gardens are on soil so that the soil can be mounded
easier for potatoes and extra slats can be added as potatoes grow, and removed at end of season back to the
stationary border. I've had good results by using huge pots for potatoes as the ability to keep adding soil is there
but the potatoes in the garden bed were bigger in size, and had better flavor.

As for the carrots it was a border also to keep grass out and prevent having to keep digging the edge border all the time
So it is tidying up the area, with the benefit of adding compost and digging in well with the soil .

As for the raspberries, it could mean it would be easier to attach netting to the area to keep the birds out.
etc and similar uses with other edibles

I tend to use cut tree trunks for bed edging when I do something like that, but to be honest, I am more of a free form of raised bed, or hugelbeds, as for the wood, I used what is local to me, pines, maple and popular are the big ones

I see that it is good to read such as this thread before doing! I was going to use a pile of 12"x12" timbers that were soaked in creosote. They came from a hydro dam here and were used as gate stops. That means they held the water back for 50 years or so. They are still in decent shape but now you mentioned soil contamination, I don't know if this is such a good idea....You think that being underwater much of this time would already have bled away anything harmful. Suggestions?

they have lots of good uses but not in the garden where you are going to grow food imo, its not recommended at all, but if you really wanted to do so I would plan on testing your soils to keep an eye on them

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Re: Raised Beds
Postby Cares » Wed May 07, 2014 11:21 am

We built raised beds out of Australian hardwood...obviously only available in Australia 😉
The timber is 100mm x 200mm stacked two high so the beds are 400mm high.
The beds vary in size 2mx2m, 2mx4m, 2mx6m with 1m pathways so a wheelbarrow moves easily down the rows and you can reach the center of the beds from either side.
We sat the timbers on top of the pavers and joined the corners with sheet metal bent and screwed into place. This makes it easy to replace any timbers easily in years to come. These photos were from when it was being constructed. "

Your setup looks great ,and easy to manage. I can't see from the photos whether you have left large holes in the paver bottoms, exposing original soil,...... but if not,i think you would have better results if there were access from below for worms/microlife to do their jobs balancing population/nutrients.

I also wondered if each raised bed was on cement slabs or was open earth for
worms, drainage, and access to deep watering for roots

Your setup looks great ,and easy to manage. I can't see from the photos whether you have left large holes in the paver bottoms, exposing original soil,...... but if not,i think you would have better results if there were access from below for worms/microlife to do their jobs balancing population/nutrients.

The area was dozed down to gravel so I don't think there were any worms left in the area anyway 😉 but the paving is only on the pathways and directly under the timber, all the area in the beds is straight over the gravel, not over the pavers 🙂

Ha!, well at least you've got excellent drainage 🙂
Maybe the over time the worms will find your oases as your soil subsides through the gravel ? ..or add some from the top. I guess in OZ they don't need winter depth so much, but more from the heat??