Raised veg beds

Were looking to bulid some raised veg beds towards the bottom of the garden

Questions we have are

What thickness of timber should we use - ive got 1.5 inch thick in my head but is this too thin ?

How high to have the bed ? the garden soil is very sandy but the veg area is a low point and can get a bit soggy in the winter (one of the reasons to raise them up to keep the veg out the wet)

What to treat the timber with - waste oil ? cupronol ? creasote ? i dont want to use anything that will effect the veg or leave traces in it

any general tips on the construction - were looking at 4 beds about 6 foot across (so we can reach the middle from both sides ) by about 10 foot long

Opinions people

 

Doesn't need to be very thick. An inch will do - but the thinner it is the more "vertical post supports" along its length to stop it bowing outwards. Decking boards are commonly used - pre-treated and relatively cheap/widely available.

Some people use railway-sleepers, which are obviously very wide, but I think they waste cropping width - in the space that the railway sleepers along both sides of three rows raised beds take up you could have got a fourth bed in!

If you have "Normal soil" underneath it doesn't have to be very tall, mine are about 6" - 9". I'm on heavy clay and that provides enough natural drainage.

Raised beds on sandy soil can make them very dry in Winter. I wonder if land drains might be better on your plot? particularly if you have a bit of a slope so that you can route the drains to a lower spot for the water to then find its way away naturally.

Don't treat the wood with anything that you don't want to eat! This is going to be right next to your food crops (i.e. you might take a different view with raised beds for ornamentals). You can get the timber pre-treated with chemicals that are deemed safe - albeit that that is probably for indoor use, and has not been tested in wet soil next to food crops ...

I've put damp-proof-membrane between my boards the soil - in part to stop the wood rotting, and in part to keep any chemicals in the wood outside of the soil in the bed. Who knows if the plasticisers in the damp proof membrane are any safer than the wood preservative chemicals in the wood? its possible to over-think the thing of course! but I would avoid anything obviously "noxious" near the food crops.

Don't make the beds more than 4' across, absolute max. You can't reach the middle of a 6' bed without walking on it, and with raised beds one of the benefits is to NEVER walk on them - then you don't need to dig them.

I just have boards around mind, with "pegs" at the corners, and at intervals along the length, to hold the boards in place.

I have quite substantial raised wood at the ends - this means that when I'm dragging a hose about it has to go round the corners of the beds, and can't escape and swipe across the surface of the beds decapitating all the plants as it goes!

You might also want to think about the paths. I've got grass, because gravel picks up on boots in winter and mixes with the soil that falls out of the beds (which also happens with bark chippings). But its difficult to mow the grass which is right up against the boards edging the beds so I strim that or weed-killer just the couple of inches along the edge of the boards. Paving / Paviers would probably be the best solution, more work to lay though.

 

Thanks for he answer Kristen

paths I have sorted - I have a massive wall built this theose horrible 70`s concrete flower style blocks - im going to lay them and fill them with gravel as a path

Land drains are a no go as the garden runs downhill to the bottom (veg bed one side fruit tree`s other) and the feild behind runs slightly up hill so were the low point

I might go the plastic route insdie the beds - i has 18inches in ny head for a height but might drop that now - i`ll see what Kirst thinks

 

Apart from any other issue 18" is a lot to import :(

For a 4' wide raised bed, 18" deep, you will deep a cubic metre of soil (one of those big builders bags) every 1.8 M (bit less than 6') of "run" length :(

You might get 6" from just excavating the paths a "spit" depth, and putting that soil on the beds. Together with some muck and compost, over the years, that is all that mine have had. So in effect mine have almost no height above the surrounding area, they get their extra drainage by the paths being excavated a bit.

 

Does the "dip" slope away to one side? Bit of a swine otherwise :(

 

we have alot of soil to put somewhere Kristen, I dont really know how high to have them, I was thinking raised veg patches would make it easier for me to look after, as I have a bad back, get rid of the excess soil we have, look tidier and hopefully not get to water logged as the bottom of the garden can get abit wet

 

I think the waterlogged bit is taken care of by a small amount of raise (based on my own experience on heavy clay, and being able to dig up parsnips at Christmas two years ago [we had -10C for about a week] when everyone else around here said theirs were frozen in the ground and unable to be extracted!)

I think "smartness" is OK on that front too (personal decision that one, though!) [Not an ideal photo of mine, this is the "wrong" end, the other end has a nice "wave shaped" end piece, which is what the hose is guided by, but I haven't got a photo to hand)




But bad back, excess soil, etc. need more height I think if you are going for more height you need to think about the strength of the retaining "walls".

I have an (ornamentals) raised bed that is knee high. I've used sleepers for that, with concrete reinforcing rods vertically linking the timbers together [holes drilled right through both layers of sleepers], and then knocked a good couple of feet into the ground below them.



Can't find the photo of it part filled. I put a perforated drainage pipe [comes on a roll] in the bottom - that's intended for irrigation, rather than drainage! so that I can fill it up with water - the raised beds is lined with pond-liner - but if you are worried about drainage you could put one in the bottom [i.e. bottom of raised bed, but above surrounding soil level], and the soil above that would never get waterlogged. In Summer you could "block up" the outlet to keep the water in and even fill it with water like I intend to (install it with one end bent up to the surface as a "filling spout").

Friend of mine has done that with his veg patch - perforated drainage pipes along each bed - and has hooked that up to both the downpipe from his gutter, and the one from his bath! to irrigate the beds, from underground, in Summer.

 

the veg beds look good - weve got a ornimental raised bed made of old sleepers weve dug up out the garden

I think we`ll go for about a foot high (will help Kirsts back ) and 4 foot wide - we`ll get a decent number of bed in the area

ill post an areil picture of the garden later so you can see what weve got to work with

Carl

 

My earlier point: Sleepers are 6" wide, so both sides add 12" to the bed. If the bed if 4' wide then when you have made 4 beds just the width of the sleepers has taken up the space of a 5th bed :(

But you can sit on them to do your weeding, have a cuppa with a chum, or contemplate your inner self

 

Hi Carl, sounds to me like you can already solve your situation with what you have. Dig over your beds wherever that may be, but then its time to shift some soil around. Move some of the sandy soil to the boggy area and vice versa. This will aid drainage in the boggy area as will digging over the beds area before raising them.

Kristen has pretty much covered the rest.

Steve...

 

heres our plot - best ariel I can find



Its the bottom right that will be the veg plot (were the green house and round green bush is in the photo )

Im going to give the wood yard a ring on monday and get some prices I think 2 planks if inch by 6 should do us with 3x3 posts

 

2nd hand scaffold boards, cheap as chips, the right depth and last for ages!

 

I thought of this but Ive had trouble finding any at a sensible proce - all the folks selling on ebay want you to buy by the wagon full

 

I used decking boards Carl

 

Hi Carl,

I want to make 2 new beds for next year and have found the same with scaffold boards, either have to it loads or travel half the country to pick up. I've decided on wooden kick boards for fencing for mine

Rusty