Concrete Low Poly Mountain Planter

I have been getting into making things out of concrete as a result of a lot of inspiration from Pinterest and youtube. This my DIY Low Poly Planter made of concrete Instructable. It is an extremely simple project which requires very little skill and tools, yet is fun and looks great. Although you may be put off by concrete because it may seem difficult to work with, it is in fact very simple to make anything you want using DIY moulds made out of cardboard or foam board.

The only tools you need are:

  • Ready-mix concrete
  • 5mm foam board available in most hobby stores like Hobby Craft
  • utility/ craft knife
  • sandpaper
  • spray oil
  • an orbital sander if available
  • spray lacquer
  • Glue (UHU)

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Making the Mould

  1. First, you will need to print out the templates I made onto A4 paper. The CAD design is also attached to view.
  2. Then you will need to cut it out along the black lines using your craft knife for the first three layers of each side.
  3. After, cut out the foam board into 10*12 cm rectangles so you have 13 for each of the levels
  4. Once you have the 3 layers for each side, start with the largest, draw it onto one of your foam rectangles and cut it out.
  5. Place the next layer on top of the next rectangle and line it with the previous one you cut out so that you the layers are all in line. See pictures.
  6. Now you will need to make the centre 5 layers which include the inlay for the plant to go. You can go off the designs or make it up as you go along. The inlay will need to be 5 layers at 3*5 cm or larger depending on the plant you intend to use. See the pictures above for reference.
  7. Now apply a generous amount of glue to the layers. It is especially important to get the glue close to the edges to avoid the concrete seeping out the mould. I just used some UHU glue which I had available but anything should work.
  8. Use duct tape so that the glue can dry and to avoid the mould coming apart.

Now the mould is complete, well done!

Step 2: Concrete

  • The next step is to make the concrete. I used some ready mixed concrete which was £5 a bag from Bunnings which is really great for how much you get. It can be used for loads of other projects as well which I intend to make. It does contain a lot of large stones which need to be removed by shaking the tub so they rise and can be removed. Alternatively, you could use a cheap sieve so that it is easier.
  • Spray your mould with spray oil or any other kind of oil so that the concrete can be easily removed later.
  • Mix up plenty of concrete with water until it is fairly thick, and pour it into the mould.
  • Use an orbital sander or vibrate the mould to remove the air bubbles.
  • Finally, let it set for at least 24 hours.

Step 3: Finishing

After at least 24 hours you can remove the concrete out of the mould. To do this you will need to tear away the foam board until it is all gone. The centre foam is a little harder to remove so be very careful not to break away the concrete. If you have a blow torch it is super effective and fun to remove the foam.

Next, you need to sand all of the edges and faces till they are flat because it will make the low poly look great, especially if you spend a lot longer finishing. I used a small flat file and some fairly fine sandpaper.

Finally, I have found that applying a clear spray lacquer finish adds a protective layer and stops the fine particles of concrete falling off. As shown by my other tests above that it looks good.

Step 4: Final Assembly

The final step is to get a small plant of your choice. Because the hole is only small I chose a small cactus which looks really cute on top of the mountain.

I hope you enjoyed this instructable which is really simple to do. I would like to say that you could 3D print your own mould and make it with silicon, that way you can make multiple plant pots. Also, you could enlarge the design to allow a larger plant to be inserted as I only used a small cactus.

Don't forget to subscribe and SMASH the like button.

Planter Challenge

Participated in the
Planter Challenge

Be the First to Share


    • CNC Contest

      CNC Contest
    • Make it Move

      Make it Move
    • Teacher Contest

      Teacher Contest

    6 Discussions