need help with new raised beds

coengApril 4, 2012

I have almost completed my 16x16 garden enclosed with 4 foot high fence panels. Looks really nice. In the mean time I've been working on the framing for my raised garden beds in my garage at night. I have 7 frames, made out of untreated 2x8s (with 2x4s for corner braces). They vary in size (four 2x4 boxes, one 3x4 box, one 2x6 box, and one 2x8 box). I will be stapling landscape fabric to the bottoms of the frames today and putting them out in the garden tomorrow.

A few questions I have at this point.

1) The area I used for my garden was previously part of my lawn. Should I remove all the grass from inside the garden? Or only the grass underneath where the frames will be laid down. I like the idea of having a grassy area to walk on when entering the garden.

2) As a cost saving measure I was thinking about filling the bottom 3 to 4 inches of the frames with the earth that was extracted when the 3-foot deep holes for the nine 4x4 fence posts were dug. The remainder of the box will be filled with organic topsoil. Does anyone think this is not a good idea?

3) Is there any other way to obtain organic gardening soil other than buying it in bags at home depot? I already bought 8 bags of Vigoro organic garden soil but haven't opened them yet. I know this will definitely not be enough.

Any other suggestions to get me started would be appreciated!

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Speaking from expirience, I would remove the grass immediatly around your raised beds. I have two 18' x 2.5' beds. The first one I did not remove the grass around and years later, 90% of my weeding effort is concentrated on removing grass growing up from underneath that raised bed. Thats even after I've put down 6" of mulch all around the bed. Do yourself a favor and keep the grass away from your garden.

    Bookmark   April 4, 2012 at 10:32AM
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toxcrusadr Clay Soil(Zone 6a - MO)

It also depends on what kind of grass you have. Some, like fescue, are very aggressive and will crawl in under the borders. If you have Bermuda grass, forget it! It's like a cancer, unstoppable.

You should be able to find someone who sells good topsoil who can deliver a truckload and dump it. You do have to be careful though. What some people will sell as topsoil may be poor quality soil, or full of rocks, noxious weeds, who knows. I'd ask at the nurseries and check classifieds for someone who sells soil meant for gardening. Usually that will be mixed with good compost and screened. It will cost you but not as much as getting it by the bag.

You should be able to throw that soil from the post holes. Unless it is really bad clay or some other kind of soil you really don't want to garden in. Even then it will eventually be mixed and incorporated into the raised beds.

    Bookmark   April 4, 2012 at 11:22AM
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Skip the landscape fabric -- it serves no efficient purpose and there's a good many veggies that will produce roots that will exceed the 8" depth of the beds. And I agree that you can a) reuse any soil remaining from the fence post digging; b) purchase whatever remaining soil/compost mix you need in bulk (bagged will be far more expensive) and c) remove the lawn in your garden area. Unless you sink the beds, grass root rhizomes will creep under the borders and infiltrate the beds. Plus it complicates mowing no end. You can use straw, bark or any type of mulch between the rows of the raised beds.

    Bookmark   April 4, 2012 at 1:54PM
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Thanks for the advice. I'll post some pictures tomorrow so you all can see what I'm up against.

    Bookmark   April 4, 2012 at 3:37PM
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I just thought of something...since I'm using raised beds for the first time ever, what should I used to support my tomato plants since the soil is much softer compared to growing them directly at ground level. I'll need something that obviously won't tip over in a gusty thunderstorm. I've used wooden stakes in the past but those are useful when you drive into the ground with a handheld sledgehammer.

    Bookmark   April 4, 2012 at 3:42PM
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Also, should I level the frames when I remove the grass around them? The ground slopes from one corner to the diagnal corner by several inches. Or is it OK to just remove the grass and plop them down on the ground?

    Bookmark   April 4, 2012 at 3:45PM
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darth_weeder(z7 NY)

Coeng , definitely keep the frames level for both looks and to get the most out of the raised beds. An easy way to shim up the low side is by using bricks or similar material. Also you could dig the "high" side down.
As for tomato stakes since the frames are made of wood you could probably screw the stakes to the 2x8's.

    Bookmark   April 4, 2012 at 4:27PM
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toxcrusadr Clay Soil(Zone 6a - MO)

Or use stakes long enough to drive through the new soil into the original ground. Or use more than one stake for extra stability.

    Bookmark   April 4, 2012 at 5:20PM
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nancyjane_gardener(Zone 8ish North of San Francisco in the "real" wine country)

I think either in the potager garden or the vege garden board there's a thread about what you use to stake your tomatoes (potager, I think)
I have raised beds and sink some T poles on the outside of the raised beds, then use pig wire to zig zag through the bed for tomatoes and heavy things that need to be supported.

    Bookmark   April 4, 2012 at 9:50PM
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Below are some photos of my work in progress. I still need to finish the bottoms of the fence panels to prevent critters from entering. So far I only did this to one panel (the one with the bag of crushed gravel leaning on it).

Should I raised the low ends of the bed frames or bury the high ends (and how)? What is the trade off? How you would do it considering I didn't use cedar or redwood for the frames. How long should I expected these to last?

    Bookmark   April 4, 2012 at 11:46PM
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It all looks fantastic, but a couple things that I would do if I were you .
1 As gardengal said remove the landscape fabric, it has no value and is detrimental to your purpose.
2. I would leave that grass, just soak the area completely, really really wet, and put in two layers of saturated cardboard, (extend the cardboard 3" beyond the outside edge of your beds.
Don't dig the beds into the ground, just raise the other 3 sides to level them out with metal concrete stakes, your beds should last at least 5 years (with the landscape fabric removed)
Fill them with bulk (raised bed soil) engineered by a local landscape supply company (look in your local yellow pages)

Use 6' rebar pounded into the natural soil at least 2' deep
(use 8' remesh formed into a circle (20" diameter)).

Google = steel concrete stakes and remesh wire, it you give your tomato plants half a chance, they will always meet your highest expectations, all of my cages are 8' tall and all of my plants exceed that height and have to be topped , for ease of harvesting.

    Bookmark   April 5, 2012 at 12:30AM
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coeng, your new garden is beautiful and I wish you much success. I just started my raised bed for the season and did something different this year. First I put down a thick layer of cardboard boxes that were cut to flatten of course, (forgot to extend out 3" though) then a thick layer of wet newspaper, then the kitchen scraps I had at the time, then the garden soil I had delivered that is full of composted horse manure and other good things. For weed control instead of using cypress mulch that only serves to tempt my cats, I am using flattened cardboard boxes.

jon, your harvest is so gorgeous. Congratulations. I can't get over the height of your tomato's. So it's rebar that is the trick to keep those babies tall and standing straight. Now I know.

    Bookmark   April 5, 2012 at 1:06AM
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Jon I noticed you have flowers in your garden plot, you never post picture of them, are they for aesthetics or for practical reasons?

    Bookmark   April 5, 2012 at 7:47AM
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A couple of follow-up questions:

1. I may ditch the landscape fabric because there seems to be a concensus for not doing it (although I've seen so many instructionals that say to use it). How thick should this cardboard layer be? Are we talking like a single layer of corrugated moving box cardboard? And what your saying is that I shouldn't remove ANY grass from the garden at all, even under the cardboard, right? Just soak the grass and cardboard, then put down the bed frame and fill with top soil?

2. Can you elaborate a little more on leveling the three sides with concrete metal stakes? What do these stakes look like, how do I attach them, and where can I get them? What do I fill in the gap with between the frame and cardboard base so the loose topsoil doesn't escape through the bottom?

3) How would I approximate how much bulk soil I need? I have (4) 2x4 beds, (1) 3x4 bed, (1) 2x6 bed, and (1) 2x8 bed. Each is 8 inches high. By my calculation that's a total of 48 cubic feet, which is just under 2 cubic feet. Any ballpark idea of how much something like this should cost me delivered?

    Bookmark   April 5, 2012 at 8:44AM
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mustard_seeds(4 -Onalaska Wisconsin)

How incredibly lovely - it is clear you have put a lot of thought and energy into this beautiful garden plan!

I have pine squares also and I painted them with linseed oil at the start. This is the start of their 5th year in zone 4 and they are grey but still strong.

I used wet cardboard over my scalped lawn, put down the square frames over the cardboard, filled with my mix of compost and soil, and used wood chips over the cardboard for the paths between. Some extra chips each year. It drains very well. Year four I raked back the chips and added more cardboard and chips on the paths since weeds were popping up in the path sections. (Maybe carpet underneath the paths would have been longer lasting for the paths?)

One suggestion I see for your area. Have you considered using the longer central rectangle in a non-fenced area? If you use it elsewhere, you would give some breathing room in the garden and you could bring the other boxes a bit farther from the fence. That way you can get at your boxes from all four sides to weed and harvest. If you did this, you could plant something non-fenced that the critters do not go for as much - for me that would be tomato - nobody seems to bother my tomato plants.

How does your trellis box work - can you get into it from the short sides? Looks cool!

Cant wait to see the pictures of your garden growing!!

:) Rachel

    Bookmark   April 5, 2012 at 9:03AM
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Thanks for the suggestions.

Right now I'm just hoping that something will grow in this garden. It better, given all the money and effort that went into it. My biggest concern are the large elm trees behind the swingset. We moved into our house in August and I remember the backyard being quite sunny for most of the day, but I may need to trim off some arteries so I get morning sun as well. I'll know by then end of May.

Regarding the elbow room in the garden, if it seems too tight as time goes on, I might move the middle box out.

The trellis works just great. I got the concept from this site a few years back (when I lived at my old house) and improvised a little. I even posted some photos a few years back after I completed it. When I moved this past summer, I dismantled the PVC and it all fit into a large rubbermaid container. When I reassembled it this winter in my garage, instead of using twine to make the grid, I used plastic coated clothesline. I think it will do less damage to the plants from the weight of heavy cucumbers. I plant cukes on both sides and they climb straight up and over the top. Having the cavity in the middle allows me to find cukes that I would normally have missed if grown on the ground. In my old garden, I didn't have raised beds. Therefore when I made the raised bed frame for the new garden, I had to make sure it fit inside the framework base (as seen in the photos). People always marvel at my trellis, wondering at first what it is. All of my nosy neighbors thought the trellis box was some sort of animal cage and that my fenced in garden was for them to have a pen to run around in. LOL.

    Bookmark   April 5, 2012 at 9:37AM
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Two garden centers local to me don't offer bulk soil, the other two in the vicinity both referred me to Allen G. Cruse (Golf Course and Landscape Materials) in Fairfield, NJ.

They carry a premium rich gardening soil and the miminum delivery is 2 cubic yards, which is perfect for my needs. At $32 per cubic yard plus $69 delivery fee (for 2 to 8 cubic yards), is this reasonable?

    Bookmark   April 5, 2012 at 9:44AM
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It is a great price, but I think you should borrow a truck and go get it yourself, to save the delivery fee.

Google = steel concrete stakes and remesh wire,that will show you what they look like.

I will post another picture of a similar bed to yours and it will show one side on the ground and the others raised up to "level", the soil doesn't fall out.

Leave the grass, all of the critters (worms and such will eat it once it dies from lack of sunshine.)

I'll post a pic of a similar situation to yours,
I needed more parking for my office , but I didn't want to give away all of the space so I make an impromptu bed over the grass, before I rocked the ground for parking.
Notice the Rebar and the Remesh cages for the Tomatoes

Totally Saturated..

    Bookmark   April 5, 2012 at 11:05AM
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That is one thick layer of cardboard. Is it necessary to make it that thick?

Why choose cardboard over landscape fabric? Why do you consider the latter detrimental?

I posted a link below of the stakes I believe you are talking about. Is this what I should use? Did you just drill holes through the frame and secure it to each corresponding hole in the stake so that the frame is level? Any idea if these could be found locally to save on shipping?

Here is a link that might be useful: steel stakes

    Bookmark   April 5, 2012 at 11:31AM
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darth_weeder(z7 NY)

The cardboard will rot away while the landscape fabric will not.
The landscape fabric will prevent the vegetable roots from entering the ground, so essentially you will have a shallow 8" container garden which defeats the purpose of a raised bed garden.

    Bookmark   April 5, 2012 at 11:54AM
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darth_weeder(z7 NY)

coeng as I said above, I would just shim under the low side with brick or wood(whatever you can find) to level it off. The soil you put inside the beds will keep them in place.
Also I used untreated 2x10's(hemlock or fir can't remember) on my raised beds and they're still very functional after 8 years although they are starting to show their age. The corners are the first to go so about 2 years ago I screwed some metal strapping on them to keep them together although you might not have that problem because you put in the 2x4 bracing in the corners where I did not.
Anyway congrats on the project and good luck growing your bounty.

    Bookmark   April 5, 2012 at 12:10PM
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Regarding the landscape fabric again...if the cardboard rots away and the roots penetrate the ground beneath my raised beds, won't that defeat the purpose of having raised beds in the first place? My concern was the chemicals in the pressure treated wood (though deemed safer nowadays) would leach into my garden over time. The raised beds were to create a barrier.

My plan is to only plant tomatoes, cukes, and herbs. Do these really grow roots longer than 8 inches? Besides, does the cardboard rot away in the first year anyway?

    Bookmark   April 5, 2012 at 1:34PM
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As the cardboard decomposes, you will find that worms will congregate and improve the soil above and below. Each year you will find better and better soil. Last year I used straw bales as my raised beds. At the end of the year as I gathered all the remains for my compost pile, I was amazed at the improvement of the soil and the amount of worms in the soil. Over time as you keep adding organic matter or compost, you will be able to dig deeper in your beds allowing for deeper stronger roots. Who knows? You may want to add other vegetables in the future.

    Bookmark   April 5, 2012 at 2:58PM
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Yeah, what they said ;-)

Also, Here is a step by step process for installing the concrete stakes and then securing the beds to them.
1. For your size beds you just need ( 4 ).take a hammer and pound them in right along side the boards on the long side of the bed about 6" in from the edge.
2. Using a level raise up one side at a time and put a screw through the stake and into the bed , do that to all the stakes and Viola, you are done.

Making the cardboard two layers thick (totally saturated over saturated ground), stop the grass from surviving the process, all the pics you saw of my impromptu bed were from the minute I made the bed, there was no lag time. The grass I see in your pics is in too good condition to assume anything bad in your soil, if you KNOW there are poisons there , don't plant there regardless, but if you are only afraid of what might be, plant away and enjoy your life.

    Bookmark   April 5, 2012 at 5:01PM
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Coeng, the trick with putting down carboard, etc. etc. really works and saves a ton of work that would be required to remove the sod. It's almost magic :-)

We did that with two new raised beds that we put in last summer and a back yard garden a couple of years earlier.

As I understand it, the cardboard, etc. essentially smothers the grass underneath and composts it. If you search on 'lasagna garden', there is a lot of information on this site and other.

    Bookmark   April 5, 2012 at 9:33PM
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scotty66(8 Hutto TX)

the purpose of a raised garden is not to seperate the garden from the earth. Raised garden beds allow you to do all your gardening from the garden path and avoid compacting the soil. Raised beds tend to drain away excess water and have better aeriation.

But yes, your plant roots will need more than 8" of soil... the cardboard will decompose very quickly with the weight of the soil, watering, worms and even the roots. Personally I think 1 layer of cardboard is sufficient to kill the grass.

my gardens are still a work in process... there are 2 raised beds in back that are 3' x 12' and the two new beds I just put in that are 2' x 8' each. The 1x2 post in the ground will suport a 3' high plastic mesh to keep my dogs out (they love tomatoes). The fence will sag and not look nearly as nice as yours.... I may have to step up my game :)

    Bookmark   April 6, 2012 at 12:24AM
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I decided to use the cardboard and paper after I read this is the worm's favorite food. My gardens are new so I want to get some worm action in a hurry. My soil is packed and mushy and a mess for anything but grass and weeds to grow in. My layering and raised bed should work out great for my veggie's. We'd been burying kitchen waste in all the front garden beds for months so they already have worms steadily at work.

I purchased 50# of alfalfa nuggets today as I understand worms love that stuff too. I'm trying to make my worms the happiest in the neighborhood.

    Bookmark   April 6, 2012 at 1:17AM
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toxcrusadr Clay Soil(Zone 6a - MO)

The newer pressure treated wood has a copper soap in it, similar to what you can buy as a spray fungicide. It no longer has arsenic and chromium in it. Copper is much less toxic than the other two (it's used for water pipes after all). I would not worry about the safety of your vegetables too much.

That said, the soil in a raised bed is in contact with the boards all the way up the side, not just in the native soil at the bottom, so if there really was a problem it would affect the fill soil all around the sides of the box anyway.

    Bookmark   April 6, 2012 at 10:15AM
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I hear you. That seems to be the consensus everywhere I looked. My boxes are made of untreated wood so the only source of contact would be at the bottom of the beds.

Interesting you should mention copper soap. When I was making the fence panels, I attached 1x4 PT boards together with the black vinyl wire mesh material in between them. During the process of screwing the boards together with deck screws, I noticed a bubbling liquid effect near the each screw head. Is this the copper soap being forced (or seemingly wrung) out?

    Bookmark   April 6, 2012 at 10:26AM
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coeng, I am using card broad for the first time to hold down weeds in my orchard. It is my understanding that earthworms love the stuff. I think it will keep most weeds at bay.
If you have 6-8 inches of soil all the better.
I think you have a good set up.
Good luck!

    Bookmark   April 7, 2012 at 12:15AM
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scotty66(8 Hutto TX)

A lot wood you buy nowadays is very fresh and thus has a lot of moisture in it, I would think that is what you saw.

    Bookmark   April 7, 2012 at 12:33AM
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emmers_m(9a/Sunset 7 N Cal)

I don't think you have to worry AT ALL about (possible) contaminants from the treated wood in your fence posts traveling laterally several feet through your native soil and underneath your raised beds where you'd need to use landscape fabric to prevent it from further traveling up into your beds or prevent your veggies roots from growing down into it.

I expect the zone of (possible) contamination around your fence posts would extend only a few inches out from the post, but maybe toxcrusadr can speak from experience there.


    Bookmark   April 7, 2012 at 11:07AM
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art_1(10 CA)

coeng your garden layout looks excellent, very well thought out and executed. Spend some time learning about gardening and once you see success you will find that you want to quintuple the size of the garden :)

    Bookmark   April 7, 2012 at 1:22PM
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thanks for all the advice, very much appreciated

    Bookmark   April 9, 2012 at 8:24AM
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now onto the next sub-project on my clip board....I have a sprinkler head located at the back corner of my property which is now going to be rendered useless by my garden. See yellow arrow in the photo below for its location.

Any suggestions for relocating it? What about making use of that zone to water the garden as well?

    Bookmark   April 9, 2012 at 8:40AM
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scotty66(8 Hutto TX)

you sure could use it for you watering you garden. setup some drip irrigation from it.

heres some cool videos about that, from "growingyourgreens" on youtube.

    Bookmark   April 9, 2012 at 7:55PM
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Just wanted to follow up on the garden I made last year. This season I decided to reconfigure the location of two of the raised beds and in the process had to move the soil contained withing them. I was completely AMAZED at how many worms I had in each scoop of the shovel. Seems like laying down cardboard under the beds really attracted the worms big time. The reason I am reconfiguring is because it was too tight to move around in my garden.

    Bookmark   March 20, 2013 at 11:06AM
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Worms dig cardboard.

Pun intended.

    Bookmark   March 20, 2013 at 11:46AM
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harveyhorses(7 Midlothian Va)

I love the idea of cardboard attracting worms. I was planning on putting in 2 more raised brds, but i have messed up my rotator cuff, I can do the frames, but not sure about the dirt moving. Also I put hardware cloth down because of underground thieves. Just thinking out loud here, but really like this idea.
As one who had horrible experience with landscape fabric glad you listened, wish I had come here first!

    Bookmark   March 21, 2013 at 3:19PM
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