[Ray and Fiona]

I'm just about to purchase timber to make my raised beds and I'm not sure of what timber to get. This is my first time to try raised beds so I've no experience in what to use.

We will primarily be growing vegatables. If I get untreated timber how long will they last? Is there a way that I can get more life out of them without having to get treated timber? Is there an organic treatment that I can give to untreated timber to extend life?

All help would be appreciated.

Regards,

Ray.

[Lius]

I used 16ft lengths of 6" x 2" timber planks €12 in B&Q, cheapest in Dublin. When you cut the planks exactly into halves and then quarters you get 4ft x 8ft beds. 4ft is the maximum width recommended as you can only reach in 2ft. I left 2ft between the beds for walking and laid weed control fabric with gravel on top.

I built my beds all 12" high (two planks high) so I can put root crops in any bed to allow full crop rotation between all beds. If you are not going to plant Spuds or Carrots etc. then 6" high will do fine.

Initially I left the planks bare as I did not want to contaminate the vegetables with wood preservatives, however they looked a bit rough after three years and I had to let "her indoors" paint the outside of the beds with wood stain which will not be in contact with the vegetables.

[Ray and Fiona]

[Lius]

Not treated, just bare 6"x2" timber planks, nice and straight, not many knots.

[pollen jim]

6" timber is not ideal, the soil will not be deep enough and u will have spillage of soil, when mixing in manure and other stuff, no treated timber, even lined with plastic, you should get at least 10 years using use scaffolding planks and pick them up dirt cheap now, i have too many raise beds to care for, but they serve their purpose well so 9"x21/2" planks 8x4ft beds, hope im not too late for ye look up ur paper adds

[Lius]

Jim,

Any of the cheap scaffold planks that I looked at were well used and splattered with paint, concrete, plaster and God knows what else which could be even worse contamination than treated timber. They were also very damaged and would look horrible in my nice back garden, that's why I ended up with new untreated planks from b&q.

I would also disagree with you about 6" high although I use 12" high to allow for root veg.

[pollen jim]

i worked on building sites, nothing really bad covers them. most sellers have them cleaned off, you were just unlucky with your dealers, it takes 5 mins to clean them with proper scraper, stuff is dry, just crumble off. even if you knew a plaster or builder they lend it to you , no problem, it only cost around 20 euro, cement and plaster wont kill you, but that said, they should be clean when selling them, we have to agree to disagree with 6" or 9" like rocken rollers, but 9" is best in most situations

[Blowin]

A far better means of constructing raised beds is to use 6ft x 1ft concrete 'boards'. They'll last for ever, more or less, and in our local yard there was an option of plain or stone patterned face with a €1 surcharge for the latter.

Mine cost me €14 apiece from a local yard (2007) and, to form a herb bed against a steepish bank, I used them two high. They're easliy supported by driving 'T' or 'H' section steel of the appropriate length into the ground with ordinary angle iron at the corners.

Having a jeep, I was able to bring mine home myself but they are rather heavy and, without that sort of vehicle, there may be a delivery charge. However, for permanent use, I think they're a great method.

[Lius]

Blowin,

The concrete boards sounds good, I also considered recycled plastic decking boards but they were too expensive.

[Blowin]

Lius - If you're interested, this is how I put an otherwise useless bit of bank to good use with concrete boards.

I find it really useful for bits and pieces. The Bay Tree is well established and I've got two varieties of mint, sage, oregano, chives and lavender. I also use it for grwing half a dozen lettuces at a time and, after I've planted out leeks, cabbages etc, any left over plants are kept in this bed to replace any failures.

[Lius]

I will be definately considering concrete planks next time.

[My Potatoes]

Is there any issue with the concrete increasing the pH of the soil?

[Blowin]

I genuinely haven't a clue on that. In fact, although I've heard folk talking about 'Ph', I don't really know what they're talking about.

The site for our bungalow was excavated out of a sloping field in 1982 and you might be able to see the rest of the field behind in the photo. Previous occupiers had used the steep bank as a dumping ground for their fire ashes from time to time. At the top it's maybe only a couple of inches over 2ft in width and tapers to nothing at the original kerbstones at the bottom.

When I 'built' the bed in 2007, I filled the space with spent growbags from a nearby strawberry farm and assume, therefore, that the main ingredient will have been peat. Since then, being convenient to the back door, we've quite often chucked spud peelings, outer cabbage leaves etc on to it and, for a specific crop, I've sometimes stuck in a forkful of farmyard manure to provide a start.

Beyond this it's matured on its own and, whether or not the concrete has had an effect on it, I've had reasonable crops of those I've listed previously, plus a few carrots, spuds and parsley over time. On this basis I don't think the 'boards' have done things much harm.

[My Potatoes]

pH refers to the acidity/alkalinity of the soil, it's the scale used. 7 is neutral, above 7 is alkaline and below 7 is acid.

Different pH levels suit different plants and crops. Lime is commonly used to raise the pH level, and concrete contains a lot of lime.

May or may not be an issue, just pondering.