How to Build a Corrugated Steel Raised Garden Bed

Corrugated Steel Raised Garden Beds

Corrugated Steel Raised Garden Beds

Last week I shared how we replaced an old hedge with a raised bed garden.  Today I’ll share how we built that corrugated steel raised garden bed and lessons we learned.

I’d seen some cool pictures of corrugated steel used to create raised beds in front yards and elsewhere.  They looked cool to me.  The thoughts of pulling these ancient huge hedge plants out by the root (if our pickup truck could do it) did not sound too feasible.  The gas line came into the house right under the hedge. Our neighbor had rented a backhoe to dig up the roots of the Bradford Pear he’d cut down.  We considered sharing it with him, digging up the hedge, but there was still that gas line.  Finally, my husband cut the hedge down with a chain saw and we built raised beds  over the top.  Chain saw did wonders.

Next my husband bought some corrugated steel scraps and some old decking plants cheap from a surplus place.  It came in various colors, which I told him was fine, I could paint them once built to whatever color I wanted.

Questions to Ask Yourself

Look at your landscaping, where are you going to place your beds?  How tall do you want your beds?  What size? Is the area mostly level or on a slope?  Will you be able to reach all sides of your raised planting beds? Are your beds centered with your windows if next to your home?  How much sun will they get?  What will you be planting in your beds? Do you want tiered raised metal beds? What will you fill the beds with?  What materials will you need? Budget? Where will you find the stuff you need?  Set aside time to build.

Building a Wood Frame for Raised Beds

The first challenge was to build a frame which we could cover with the corrugated metal.  We tried adding the metal inside the frame, and outside the frame.  We preferred the metal outside the wood frame with a bench like ledge in the front.  Something to set things on, sit on, etc.

raised bed wood frame

Alternating Corners on 4′ by 4′ Frame

8' x 3' raised bed corners

Corners of the 8′ x3′ planter

Stacked raised bed frames

Stacking Frames

We built boxes about 4′ x 4′ and 3′ x 8′, and a custom sized tier  box for the front.  You can use whatever size you wish, one which works well with your landscaping.  The old deck planks we had were about 8′ long.  We cut some planks in half for the 4′ x4′  beds and the sides of the 4′ beds.  On the 4′ x 4′ bed we alternated the corners as you can see above to keep the beds square.  For the 8′ x 3′ bed we placed the shorter 3′ lengths between the 8′ lengths so the planter was no longer than the 8′ lengths. We found it easier to build one frame on top on another.  Saw horses would work too.  You can also use another size for your wood.  Use what you have or can find a great deal on.

Opps! Legs on Outside of Frame

Opps! Legs on Outside of Frame


Better, Legs on Inside of Wood Frame

Next we added legs.  As you can see we used wood screws and a drill to hold it all together.  First we added legs to the outside, but that didn’t work as well when we added the corrugated metal to the outside of the frame.  Thankfully you can use the drill to back out the screws and move the legs. Put the legs on the inside of the frame.  Decide what height you want your raised beds to be, make your legs a littler longer and you can pound them into the dirt.  We varied the height of our beds for visual effect, so some would have deeper beds for deeper roots, or simply easier to reach.

Raised bed frameOn the longer sides (more than 3′) we added a 1″ x 2″ board at the bottom.  Keeps the metal sides from bulging on the sides and attach the sheet metal.

Add Corrugated Steel

First, a disclaimer.  Each of you are responsible for your own safety.  Cutting the corrugated metal for your raised bed garden, requires precaution.  Sparks fly, the metal is sharp.  I used heavy work gloves when handling the stuff.  While cutting we used eye protection, ear protection, gloves and quickly switched to long sleeves.

We found a blade for my husband’s circular saw which cut the metal from Home Depot.  You don’t use the same blade for cutting metal as you do wood.  Or you can have the metal cut for you at places like Lowes or Home Depot.  Simply buy it in your desired color.  Know ahead of time how tall you are making your planters so you know what size pieces to cut.  Save you both the cutting and painting.  Keep in mind the metal sheets overlap.

corrugated steel on saw horses

Corrugated Metal on Saw Horses


Overlapping Sheet Metal

Top Edge of Planting Box

Top Edge of Planter Box

Adding Sheet metal

Adding Corrugated Steel to Raised Bed Frame

To cut the metal we laid it across 2 saw horses, marked the lines.  I held the metal while my husband cut it.  Handling with gloves always.

Next we screwed the metal to the frame making sure the top of the metal was slightly below the top of the wood.  Don’t want to cut myself when working in my beds.  Much shorter screws for metal instead of the longer wood ones we used before.  As we wrapped the metal around the frames, bending at the corners, we overlapped the metal sheets.

Painting, Oiling the Raised Garden Beds

I found this easier to do before moving the planting beds to their location.  For the wood, I simply rubbed it with linseed oil, plant friendly.  Watch out for splinters!

Painting the corrugated metal not as easy.  If you get the metal in whatever color you want, skip this step and you are ahead.  Saves you the time and money of painting. I wanted more of a copper/bronze color so I used a Rust-oleum metallic spray paint.  What was I thinking?  It took several cans, fingers get crapped.  I should have gotten a can of the same paint.  Another issue I was reading about in the middle of painting was painting galvanized metal, some of the corrugated metal I used was galvanized.  I did wipe it down with vinegar wash, rinsed, dried before painting.  Time will tell how well it holds up. But it is a good way to use metal scraps.  If you are buying corrugated metal, get the color you want.  If using scraps, keep it that color or paint.

Placing Corrugated Steel Raised Garden Beds

Walking Space Between Planters

Walking Space Between Planters

The completed planters aren’t that heavy.  We will fill them up after they are placed.  Easier if 2 people carry them.  We placed ours about 18″ from the house.  I wanted to be able to walk behind them.  More space would be less squishy, but this works for me.  My longer bed was 3′ wide instead of 4′ for both visual and practical reasons.  I planned on trellising plants in this raised bed and from experience a 4′ bed is hard for me to work from the back side of the trellis.

It would look weird if your planters were slanted this way and that.  I wanted mine more or less level.   We used a level, digging into the dirt in the high spots, or adding dirt to the low spots, the legs being a bit longer than the bed, were pounded into the dirt with a mallet, or placed into a dug out hole.  We had to cut a few roots out of the  way from the previous hedge.

Keep in mind, if on a slope, you should have made one end of your planter  longer than the other, keeping the top level.

Step back and view your work, see if you need to make any adjustments before filling the raised planting beds.

 Finishing Touches


Bench hanging over planter


planter bench

Planter bench

Benches. Can’t forget the benches.  I wanted a bench I could either sit on or/and set tools on while working.  It isn’t the widest bench but works for my purposes.  The first mini bench we did, hung over the planter box.  We decided it was better to have the bench overhang the outside some.  Thus we centered the “bench” plank over the top of the frame’s edge.  My grandkids and the cats believe I built these as a place to climb.



Trellis. Lots of viney plants, gives vertical interest, more growing space.  After pricing trellises we decided to make our own.  We painted them to match the trim of the house.  I like the way it looks on my corrugated steel raised garden beds.  But for the plants, it may have been better if I’d treated the wood with Linseed oil instead.

Corner Planter Bed

Corner Planter Bed

Tying It All Together.  The front corner needed more help.  We still had some unused planks.  I created this corner space, planting strawberries, garlic and spiderlilys. Adding wooden stepping stones for easy access.

Fill ‘Er Up. Now for the fun part, although designing is always fun.  First I put down a few layers of cardboard. The deeper planters we added rotting wood and shrub trimmings, then filled all planters 3/4 full of compost.  Our city has an inexpensive source. Then I added garden dirt, rabbit poo, organic fertilizer, watering as I went along.  Yeah!  Plants were added next.   Then mulch.

Walkway.  Future project is adding a tinted cement walkway in front of the front and corner planter.  High traffic area and not much grows there.  I will also continue to build more planters around my yard.

You know you are doing something right (or horrible) when the neighbors slow down on their way home from work to stare at what we were doing.

Questions or comments please reply below.  I’d especially like links to any raised beds you have.

See also:

Replaced old hedge with corrugated steel planting beds
Raised Veggie Beds Loved these beds, my inspiration
Meet the Material – Corrugated Sheet Metal



How to Build a Corrugated Steel Raised Garden Bed — 6 Comments

  1. Hi there, Great tips by the way and thank you.
    I did have a question though. I’m hoping you can answer it for me
    since you seem to be pretty knowledgeable about gardening.
    Are there any herbicides that will kill grass and/or weeds,
    but will not kill flowering or succulent plants or herbs?
    If you had some insight I would greatly appreciate it.
    Elitehort recently posted..ElitehortMy Profile

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