raised beds - what is a good size?

[Oleander]

Hello all you helpful people

I have persuaded the OH that I need some more veg beds, and we have found a place to fit three raised beds, against a sunny south-facing wall. The plan is for three raised beds, about 1 metre wide and 2.25 metres long. The longer side will be parallel to the wall.

The sides will be raised by a double layer of railway sleepers, so about .5 metres high/deep.

Will this size/shape work, or should we make some adjustments before we take the plunge? We could make them slightly wider i.e. more than a metre, but not too much or we won't be able to reach the back of them!

Looking forward to reading your comments!

thanks

Oleander

[jammie*dodger]

I just built mine. made it as large as I could - 3.6m x 2.4m - we've got quite a small garden and 2 kids who take up most of it.
It was also 300mm deep. I can tell you one problem i've seen, that took a lot of soil to fill. I now have loads of space for manure/fertilizer. I've already composted a 1/3 of it and got it up to a good level so that I can plant some wintering veg. The last 2/3 will get a good amount of manure in it and covered over with topsoil. I'll then dig it over next spring before planting the rest of the veg.

[jammie*dodger]

just did a quick bit of maths and by my reckoning 3 beds at 50cm deep is over 10cubic meters of soil to fill it. Is that right?

[Oleander]

10 cubic metres! I never considered that - so how deep is deep enough?

[Two_Sheds]

The point (well, one of them) of raised beds is that you don't ever walk on them.

Therefore, you need to be able to reach all parts of the bed - so that would mean they should be no wider than twice the length of your arm (so that you can reach the middle)

Length isn't quite so crucial

[jammie*dodger]

Yep, i've run a small board down the middle of mine so that I can walk on it if I need to though. The main reason I built the raised bed was to use up all the excess soil that the builders left after building my house/new patio. Just surprised me that I have only about 2/3 filled it and most of the excess soil has now gone. Does mean I can get plenty of organic matter in there to rot down over the winter though.

[jammie*dodger]

Therefore, you need to be able to reach all parts of the bed - so that would mean they should be no wider than twice the length of your arm (so that you can reach the middle)l

In that case 1m wide sounds perfect. I suspect you don't need it to be 50cm deep though. Depends what you're growing I suppose. Would lots of root veg mean a deeper bed would be preferable?

[Two_Sheds]

Well, my carrots rarely get longer than 6 inches. Parsnips ... about 12 ?


sorry, I think in Old English for gardening - metric for dressmaking, for some reason

[Alison]

The ones I'm planning for the new lottie will be 4' wide (ie about 1.2m) and can be accessed from both sides. They'll be of various lengths depending on location. Did consider wider ones but don't want to be walking on them, even on a board, as my weight will still be transmitted into the ground leading to some compaction near the board.

Re the depth, it depends on what you have below the bed, ie what the soil is like. If it's pretty poor draining then it's worth either improving that before you build the bed or making a deeper bed.

[taff]

I've been making them for the garden this year.I made five of them, they're all 10ft by 4 ft, and only about 6-8 inches high.
I de-turfed first, then made the beds, then dug over the earth, removed as many weeds as possible, then put compost and cow poo on the top, and they are all running at about 2 or 3 inches shy of the top.
I'm intending to no-dig, and just add manure/compost, and then keep building up the sides as I go.
It isn't really necessary to have them that deep, unless you're unable to bend down, and if you are using railway sleepers, you could also just keep building them up as you add more material to them.
If you are stripping turf to make room for them, stack it upside down, cover it with dark colour plastic, and leve it to rot down for free topsoil next year.

[ava]

just did a quick bit of maths and by my reckoning 3 beds at 50cm deep is over 10cubic meters of soil to fill it. Is that right?

I think 10m3 might be overestimating it a bit. My calculations are:

W x H x L = 1m x 0.5m x 2.25m = 1.125m3 per bed, makes 3.375m3 in total for 3 beds.

However, I tend to agree with some of the other comments and think that 1m is a bit wide as you won't be able to reach the part of the bed which is next to the wall. I would say 0.6m width maximum and that should include the width of the sleepers.

Happy building!