raised beds

Hello,

I am interested in making raised beds in the garden. I have not done this before, so I have a couple of questions:

I am thinking of using wood due to cost, i.e. it is cheap. I see some people use pressure treated decking boards like these:

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Is this the best timber to use?

Is there a danger of the preservative leaching into the soil? I was hoping to grow some vegetables to eat and do not want to poison myself!

Some web sites suggest putting a plastic sheet between the wood and the soil to prevent this contamination but other web sites do not mention it; is it necessary?

What is the best way to screw four pieces of timber together to make a rectangular raised bed? I was thinking that I would need to sue a piece of 2x2 in each corner and screw into these. Half of the 2x2 could be buried in the ground to anchor it.

However, is anchoring necessary: will the weight of the soil no hold it in place?

Do I need to 2x2 at all, as I have seen some beds where the ends have been butted together and just screwed through.

What is the best way of doing things?

Thanks, Stephen.

Reply to
Stephen
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I don't know the answer to your other questions, but I have used decking, and I wouldn't attempt to screw into the end grain. You might get away with it, particularly if you put glue in the holes.

Reply to
GB

Sounds like you already know the answer: opinions vary. The high toxicity preservatives of the past are now banned.

You can screw it either way, into 2x2 is much stronger. Anchoring... if you do something accidentally to lift the wood, it will be lifted. There aren't really any mysteries here.

NT

Reply to
tabbypurr

wood will last about 5-7 years before it rots Whatever wood you use .

Concrete blocks or bricks, and mortar

Reply to
The Natural Philosopher

I used 6x2" tanalised softwood when I did mine about 5 years ago.

Most of them will be Chromiated Copper Arsenate (CCA) these days, and research suggests that leaching into the soil over extended periods is minimal.

Not for that reason. You may find it improves water retention - but that may not be a good thing.

Corner blocks are easy:

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For anything except a very small or tall bed I can't see anchoring being required.

You will get a stronger joint with a corner block.

If you want a really strong joint, then cut a finger joint into the ends!

Not sure there is a "best" way - much depends on how difficult you want to make it, and what tools you have available.

Reply to
John Rumm

Gravel boards are cheaper and just as good:

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I made my raised beds from pressure-treated gravel board, and have grown and eaten several types of veg. As far as I am aware, I am not dead yet.

There is a school of thought that this leads to water being trapped between the polythene and the wood, and actually shortens the life of the wood, but I do not use polythene so can't comment.

I used lengths of cut arris rail at each corner:

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If the ground is level, no. But if it is on a slope, I would anchor it in some way otherwise it might move slowly down the slope.

They won't last. Clay soil drying out and getting soaked will move houses. What do you think it will do to a raised bed held together so inadequately?

A cheap way, if you can find someone who is getting rid of old 2 x 2 paving slabs, is to bury these on edge up to half in the soil, and make beds with multiple slabs next to each other. These will be pretty stable in loam or clay soil, but not in sandy soil. They won't look particularly nice, and will move slightly over time, but if they're free...

Reply to
Jeff Layman

Not likely nowadays, it's more likely to be an organic copper compound.

AJH

Reply to
news

Dead people are always unaware that they're dead.

NT

Reply to
tabbypurr

Not necessarily the best way but if the size suits you then using pallet collars can be a quick way to get started , this sort of thing as shown on this ebay link

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They stack on top of each other, Lick of fence paint on the outside and they can look fairly respectable.

G.Harman

Reply to
damduck-egg

The Undead don't seem to be aware that they are dead. Or is that a contradiction in terms? ;-)

Reply to
Jeff Layman

Fascinated by this chap on Gardeners World last week. Did a quick search and found this:

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Step by step "guide for dummies" :)

Reply to
0345.86.86.888

You could use western red cedar or thermowood to avoid the problems with preservatives. Thermowood is decking that been cooked and is fairly rot resistant. Sometimes B&Q have it.

Red cedar is not cheap but pretty rot resistant untreated (not as much as teak though).

Reply to
Tim Watts

Just put a 2x2" batten down each inside corner and screw into that.

Reply to
Tim Watts

Red Cedar is nice but really expensive at the moment. You would probably find English white oak (also durable without treatment) cheaper.

Another option can be reclaimed railway sleepers. Just lay them up like large lego bricks, drill a hole a knock a spike in at the corners.

Reply to
John Rumm

If you are doing to assist a disabled gardener, then don't make the beds too wide as the use might not be able to reach into the middle!

I got this wrong when I did mine for SWMBO and now I have to do various jobs in the centre of the beds and I hate gardening!

Long and narrow is the best arrangement.

I also laid in 15mm copper pipe and a valve into the corner of each bed and connected seep hose to each valve. This allows timed automatic watering with the option to adjust the flow rate in each bed from 0 to 100% During wettest months the water feed is turned off and an extra valve opened (belt and braces possibly) so that freezing does not force the joints apart.

Reply to
Bob Minchin

I built 3 large raised beds I do not like idea of wood being in contact with ground - especially ground you need to keep moist.

I built mine out of 100mm concrete block ... then battened and clad outer face with wood and fitted wood 'cill' capping.

More work - but will last a lot longer .... unless you use sleeps or similar ...decking won't last that long.

Reply to
rick

I built 3 raised beds, opportunitstically as Wickes were selling decking boards very cheaply. 3 years down the line, they're showing no signs of rot at all.

I used 2x2s in the corners and where the ground wasn't level, I lined parts of the insides with some old quarry tiles that were lying around in the garden from before my time.

Reply to
GMM

Wood preserver is crap these days. It won't last more than five or six years. Plastic might help in this respect.

Reply to
harry

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