steel planter box

What’s a good activity for a crisp fall weekend? Welding, naturally.

In our deck reveal post last month, we showed you the raw steel panels that we bought off Craigslist and had cut by a local sheet metal shop. Since then, they’ve been hanging out in the backyard, working on their patina. We had no real timeline for getting them built, but last Sunday (in a passing moment of boredom), Kyle got the itch to weld. 

The boxes were designed to maximize the 4×8 sheets of material and limit waste. Since the north box needed to be about 10′ long, Kyle built one 8′ box and one 2′ box, the smaller of the two going in first. 

The root barrier and pea gravel run underneath the planter locations. Since it would have been impractical to build the larger box in the shop, Kyle just welded the four pieces in place. But first, he used the laser level to place small concrete pavers at the four corners, each at the appropriate elevation to ensure a flat base to build upon.

The great thing about these DIY planter boxes is that the welds are on the inside and since they’ll be covered with dirt, they don’t have to be pretty.

To keep the larger piece of steel from bowing, Kyle welded pieces of rebar (leftover from another project) at staggered locations to provide more rigidity without compromising future plant placement. 

Finally, he attached the boxes to the deck framing with stainless steel lag screws. The boxes are heavy and would take a considerable effort to move, but we thought this step would help prevent them from settling into the dirt over time.

The smaller box was built in the shop, hence the steel plates at the base for extra rigidity. We’re thinking maybe a small ornamental tree here? 

It’s always exciting when a project finally comes together. Ipe, meet steel. You are one sexy couple. Heck, even the pea gravel looks good. (Although, damn you needles. You’re not even from our tree!) 

…and on the opposite end. Hello lovely. 

In less than six hours, the whole thing was done.  The steel has already rusted a nice amount since we brought it home and should continue to weather and change colors. (FYI – the steel is thick enough that it will take many, many, many years to rust through.) The slightly mottled look is due to uneven drying from some rain earlier in the day.

Oh. Excuse me – Bailey would like to interject and show you his new Halloween bandana.

Ok, moving on. The remaining steel is for the boxes on the other side of the deck, though we’re thinking we might need to build the awning first to make sure a certain rain chain detail is properly composed…

We also probably won’t fill them with dirt or plant anything until Spring, which should give us plenty of time to contemplate our options. Tall grasses? Edibles? Something that is resistant to death-by-zerbey?

At any rate, planter box #1 is done. Including the cost of the steel and cutting, the two north boxes set us back about $250. It’s not pocket change, but if you’ve ever priced custom steel boxes or even the small ones that some companies sell, $250 is a bargain. A bargain that should require zero maintenance. We like.


40 Responses to “steel planter box”

  1. So cool! Love this. The steel looks really sharp with the ipe.

  2. Helena says:

    Looks fantastic. Before you fill I would recommend thinking about integrating cables for lighting and a potential automatic watering. It can try out pretty fast in pots and grasse lit from underneath is so nice in late summer and in the autumn.

  3. ModFruGal says:

    What a good looking planter box you’ve got now! Jealous…welding skills are on our to do list, so we can be fancy too…one day. Great job.

  4. scotdog98 says:

    Love Bailey’s expression 🙂 That planter is gorgeous!

  5. KeLLy Ann says:

    I’m not sure if it would work because I’m not really sure of the size, but if a Lemon Tree would be possible, that’s what I would plant in the smaller box. The bigger one would be great for an Herb garden.
    Those do look wonderful!

  6. Heather says:

    Gorgeous, as always! I agree with Kelly Ann about growing herbs (and if you can figure out a way to grow citrus in the PNW let me know 🙂 )

  7. Gavin says:

    Is there something you put on them to stop the patina/rust? I assume the rust will run onto concrete if placed on it? Also what is the thickness of the sheet steel? I’ve always wanted to do this, but thought it was out of my reach (i don’t know how to weld, but know people who do).

    • Kyle Z says:


      1/4″ thick plate. Yes if you put it onto concrete it would rust onto it. We’re just going to backfill with topsoil. We like the rust so we’re just going to let it do it’s thing. I used a pretty basic wire feed mig welder.

      • Gavin says:

        I dig the rust too.. just not on the concrete. hehe. I’ll figure out a way to work these into the landscaping some how. Thanks.

  8. Kyle Z says:


    Another option for you might be to look into Corten Steel. After it’s initial formation of rust, it stops rusting to protect the steel and give it longer life. It’s about twice the cost of regular steel which is the downside.

  9. lena says:

    Herbs & edibles!

  10. As with everything you guys do, it looks great!! 🙂

  11. Brian says:

    Love the planter boxes…really beautiful. I’ve actually designed a home that is currently under construction and we are using corten on a portion of the exterior and are just beginning to discuss landscaping strategies. I have been thinking it would be great to continue the material palette from the house into the landscape and this really is a great way to do. I really love the contrast between the wood and the metal…great work!

  12. Ron says:

    they do look lovely.

    You might want to consider slipping some stainless washers between the steel and the deck. It would create a drainage path and some air circulation. It appears that they are tight against the end grain of the ipe and might cause water to collect there and not allow the decks boards to dry.

    • Kyle Z says:

      I like your attention to detail Ron, we went back on forth on if we should do that. In the end I wound up treating the ends of the ipe with a wax sealer. I’m more concerned about the 2x joist underneath getting wet on that side and not drying out. I’m thinking I’ll add the washers;)

  13. Dorothy says:

    Beautiful containers. Suggestions for the tree/shrub in the smaller unit: Azara microphylla (several forms) or Leptospermums (Tea Trees) (several forms). Full descriptions at which has fantastically unusual plants for the NW. Some are available from City People’s Garden Store on Madison, though their stock is low for the winter. Some are growing in the Washington Park Arboretum. Another good source of plant information for the NW is

  14. I absolutely love the way that steel looks with the wood. Fabulous combo and I swear every time I stop by your site I’m one step closer to finally teaching myself to weld.

  15. hjc says:

    I think tall grasses would look amazing planted there. They would give you a nice screen from the neighbors as well. Great work as always!

  16. laurenwastal says:

    I think you guys should plant a Christmas tree in one of the boxes :). You could decorate it throughout the years as it gets bigger (with PNW weather resistant ornaments of course!).

  17. Dave says:

    Architects ROCK!

  18. Nick Klaus says:

    That is wicked cool. It’s times like these I’m glad I have a brother who knows how to weld. If only I also didn’t have a black thumb, I’d want a mini one of these for my space.

  19. Maisie says:

    Planter looks amazing. Got a real inspiration buzz for next summer.
    And Bailey is so sweet with his bandana <3

  20. Robin says:

    The planters look great! A dwarf conifer would be perfect in either of the planters. In a container you need perennials that can handle one or two zones colder than your zone so conifers would be perfect as they are so hardy. Dwarf just means they won’t outgrow the box for many years. Your area is perfect for conifers…some of the best conifer nurseries in the country are in the northwest. You can read up about the many options available here:

    • chezerbey says:

      Awesome, thanks for the tips Robin! I didn’t realize the part about the zoning for planters, but it makes total sense!

  21. Katia says:

    You guys are like Apple. You make simple things look so good.

  22. Brian says:

    Hey guys, I love these planter boxes. Thinking about doing some myself. What gauge of steel did you end up using? Looking into corten…and as you mentioned…it can get pretty expensive.

  23. Stan Banfield says:

    Nice work, just watch out you don’t get cut by the rusted metal….can you say tetanus shot?
    I’m looking at doing something like that but for collecting rainwater from one corner of my roof.
    I’d be using a large plastic container of sorts to place under the downspout and then have a rain-chain fall to the screened top of the tank.
    Tank will be covered in metal of some kind(not sure what kind yet).
    The tank will have a pump inside for watering garden and plants nearby.

  24. Sam says:

    Your planters look great. I’m inspired. Thanks.

  25. espiritiv says:

    What is the width and height of the planters?

  26. Juan says:

    Do you have any problems with steel planter box transferring heat to plants on hot days. If so how did you prevent excess heat from killing plants?
    Can you recommend a supplier of weathered steel?

  27. Seth says:

    Wondering what gauge/thickness of steel you used?

  28. Paul says:


    Awesome planter boxes! I’m looking to do something similar but am finding it hard to source affordable raw steel. Just out of interest what did you pay per 4 x 8 sheet?


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  1. […] the end of the month Kyle squeezed in one more project – a steel planter box for the north side of the deck. We still need to fabricate two additional boxes that will go on the […]

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