Building Raised Beds- How To Questions
March 26, 2010 at 2:42 pm #28978
Not sure if this is the right forum for this or not, but here goes. I am building raised beds in our backyard for vegetable gardening. Have a few questions:
1. How deep should they be?
2. What type of wood should I use? I’ve always heard to use treated wood outside but are all those chemicals going to leach into my soil?
3. How long should they be? I’m going to make the width where you can reach to the middle from one side so I never have to walk inside them to harvest.
4. Should I put anything along the bottom of them to line them? It’s a pretty barren backyard, few grassy patches but mostly just old dirt and japanese wisteria roots. I’ve got a good bit of old cardboard that I could put down.
Thanks for the help! I’m new to the whole raised beds thing, first time I’ve had a yard big enough to have them. I’ve always had to garden in pots before now.March 27, 2010 at 1:56 am #29264
Don’t use pressure treated as this can be toxic to both humans and plants. The best alternative in your area, would be either Osage orange or Black locust which can be found at a local saw mill and will last an extremely long time in contact with soil (50years+). Dimensional framing lumber (spruce, pine or fir) from the big box stores will only last a few years, but is readily available and inexpensive.
Cornell has a fact sheet on raised beds here: http://www.hort.cornell.edu/gardening/factsheets/vegetables/raisedbeds.pdf
And Clemson has one here:March 27, 2010 at 2:06 am #29265
Another idea: Wattle!
Next year I am planning to make some raised beds in my vegetable garden with wattle fencing instead of lumber. This year I am planting a willow hedge that will be coppiced and harvested for willow rods (my husband the boat builder wants to build willow boats). I was searching for things I could do with the rods, when I came across this site.
Scroll to the bottom for a description of wattle used for raised beds.March 28, 2010 at 2:28 am #29272
That wattle is really pretty. I would like that look for some of my ornamental beds that I have plans for after the raised veggie beds are done. So I’m guessing it grows pretty quickly?
Those fact sheets are really helpful. So basically it sounds like an 8″ bed will work okay. I think I’m probably going to make them about 10 feet long. Could I use treated wood if it was lined with something on the inside? I don’t want to use framing lumber type stuff b/c I’m afraid it will just get a lot of termites and I don’t want to rebuild these in a few years. I’m not sure what the availability of local woods is but I’ll check. Thanks for your help! I really appreciate it.March 28, 2010 at 2:56 am #29274
I actually was just at my local county cooperative extension today and the subject of raised beds came up- someone was asking the same question about lining treated wood. The cooperative extension agent said that people have done soil tests and lining the beds doesn’t keep the treated wood from contaminating the soil, so the extension is really recommending not to do that either. The agent mentioned that his raised beds were made from Hemlock and were 8 years old. He said that the beds would probably need to be replaced sometime in the next few years as they were wearing out where he had screwed them together.
As far as the willow is concerned, this website has all the information!March 28, 2010 at 3:13 am #29275
Leslie- Thanks so much! You are a wealth of information. After reading this and doing some other research– the treated wood idea is out, even with a liner. So what to do now? Not sure. I did some research on the two local woods, couldn’t find any suppliers. I could try pine or some other framing lumber I guess, wish I knew how long we would be in the house, it might last , it might not. I guess time will tell.
My dad had the suggestion of painting the pine or other such lumber with an outdoor grade paint but I’m thinking that unless I get something environmentally friendly that there is still some possible chemical leaching problems there. Wish I had time to grow some willow but I don’t think it will be ready before my seedlings are!March 31, 2010 at 7:22 pm #29292
I have three new ones that I am just finishing and filling with soil/compost, and I used black locust, which is in good supply here and can be bought rough hewn at a local mill. My old beds were from 2×12’s but this time I went with 2X10s.
To conserve on $$$ and materials I try to make waste nothing and make them in multiples or half-lengths of available sizes, so the length will be a multiple of 8 or 10 feet and the width a half of 8 or 10 (4 or 5, of course).
When a bed is more than 10 feet we install a cross-piece at that point to prevent bowing of the sides. And we use thick stakes at the corners and every so often down the sides for stability (like 2×2’s).
There are some pix of them (unfinished) in this recent slideshow on the blog:April 1, 2010 at 1:41 pm #29294
Has anyone considered using Concrete blocks? They are cheap, easy to set up, don’t leach into the soil, and as a bonus you can fill the holes with soil too and plant herbs or flowers around the perimeter. Of course, they won’t look very nice unless you painted them. I would recommend using a few stakes or rebar to hold them together. Also, they are 8″ deep so you would get the depth you are looking for with the blocks.April 2, 2010 at 2:01 am #29295
I really like the recycled metal boxes made in this article: http://www.sunset.com/garden/how-to-build-raised-beds-metal-00400000040098/
They look great and will last forever. Seem pretty cheap too! I would like to do some of these this year. The ones I have now are made out of cedar beams salvaged from a construction job.April 2, 2010 at 10:30 pm #29296
I built raised beds last year. I wasn’t able to find any of the recommended untreated wood at a reasonable price and ended up going with fir 2x10s. I think they’re going to last a while, and by the time they rot I’ll be ready for a change, or the beds will be so full of yummy organic matter they’ll no longer need the frames.
The beds are 4 feet wide, and I couldn’t resist making a design out of them – http://www.flickr.com/search/?q=raised%20bed&w=97529007%40N00April 3, 2010 at 1:18 pm #29303
Thanks for all the wonderful suggestions! I was hoping to build my beds next week, however it looks like it will be May before we can do them b/c the arborist can’t remove our trees until the end of April, so plenty of time now to figure out a plan. We are getting several pines removed to let in some sunlight into our backyard so we can garden. I’m beginning to think I may go the route of getting regular pine boards and seeing if I can find some kind of environmentally safe coating or paint to coat them with since I’ve got a little more time on my hands now.
Boodely- thanks for linking pictures to yours! Those are fantastic, really got me thinking about the shape of my beds and maybe trying to add a little design element with them instead of just my straight rows! Did you have any problems with your grass growing through once you got your cardboard and soil down? I want to do a similar process in my front yard and smother part of our grass to start a flower cutting garden.
Those metal boxes are fantastic, but probably would be very expensive for 6 raised beds!April 5, 2010 at 1:17 pm #29304
ok heres my question: i want to start a garden in an area that is now grass. it is a circle in the middle of a driveway. i’ve read you can cover the grass with newspape or cardboard. my question is after i ut down the paper can i just cover it with compost and soil and start planting right away. this space is a few inches deeper than the driveway so can i fill it with new soil?April 12, 2010 at 1:21 pm #29347
When there are gaps between the ground and the raised bed frame (due to unlevel ground), what is the best way to contain the soil? Landscape fabric?April 18, 2010 at 5:57 pm #29381
I posted a little slideshow to explain this better. It’s here:
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