DIY Microcement Planters – my new favourite creation!
This post is all about how I built my DIY microcement planters using basic tools and materials and with the help of a DIY microcement kit. I’m so excited to share this DIY microcement project with you because it was not only my first time trying an outdoor microcement project, but also my first as a brand ambassador for Concrete Lab! (Ad info: marking this content as an ad because I work with Concrete Lab, but this tutorial is my own work and not a sponsored post. The links marked * are affiliate links which doesn’t change the price for you but can drive a small commission on successful sales. I’ve always loved transforming an old planter or building something from scratch, so if you’ve been wanting to try DIY cement planters, this is a great project to start with.
Keep reading for my full step-by-step process, plus a little thank you: you can get 10% off your own Concrete Lab order with my discount code CDS10!
Build a strong frame
First things first, start by building a strong, secure frame. I recommend using treated timber so the planter will last outdoors, but if you’re planning to grow anything edible in the planter then check its a suitably treated timber (ie avoid some of the chemical ones). Use wood screws to fix everything together securely. Large planters especially need a sturdy base, it’s a good idea to build on a level work surface to avoid wonky edges later on.
I wanted large rectangular planters to create a focal point and frame the entrance to my almost finished outdoor kitchen area, this therefore dictated the dimensions of the planters, but the great thing about making your own is you can choose the size, rather than being limited to off the shelf sizes. I went for 120cm x 60cm x 30cm. I tweaked the length slightly to create the least amount of wastage possible as buy gaint sheets of board and cut them down (this is much cheaper) & I made use of the in-store free cutting service at B&Q this time to save on effort.
Note:
I wanted the planters to look like they were solid, but not as solid as the timber I used for the main frame, so I made the frame shorter than the cladding and then added a batten to the top edge of the planter which, once microcemented over gave the exact look I wanted without sacrificing any of the strength or stability from the solid wood frame.
I left the bottom open for drainage, but you could make a base (if you plan to move the planters about or say wanted to put them on wheels) as long as you make some drainage holes.
Clad the DIY planter
Next, clad the frame with OSB board. (Note: You could also use cement board or tile backer board and both these options would be preferable if you have the budget as will require less effort to get waterproof, essential for an outdoor project, but OSB was a budget-friendly choice for me.) One important tip: remember to cut your outer sheets wider to allow for the thickness of the boards where they meet at the corners. My OSB board was 9mm thick, so I allowed an extra 18mm in length to get that nice snug corner.
Fix the boards to the frame using countersunk screws for a neater finish.
Prime the outside of your DIY planter
Mix up your Concrete Lab primer and apply it to the outside. This helps your microcement stick properly and avoids unwanted air bubbles in your final coat. As the OSB was quite porous, I used the less dilute version of the primer as advised in the Concrete Lab instructions. For a change I applied the primer with a paintbrush – I’ve always used a foam roller so wanted to test this as an alternative. I found it harder with with a brush and recommend using the roller.
Seal the inside
Before adding the cement mixture, I gave the inside of the planter two coats of durable outdoor garden paint to protect it from the elements. I used my paint sprayer and used up leftover paint that I had from the outdoor kitchen. It’s a good idea to do this step with a dust sheet underneath, as it can get messy! It’s important to seal the board if you are using something that’s not designed to be used outdoors like I was.
Mix and apply the microcement
Now for the fun part: the microcement! Following Concrete Lab’s instructions, mix up the cement mixture. (You now don’t need to add water to the mix so it’s super easy, you want the consistency to be just right so it bonds well.)
Mix well in a bucket and be sure to scrape all the powder off the edges.
I use a mixing attachment for my drill and find this is a great way to get it mixed thoroughly.
Apply the first coat with a smoothing spreader, keeping it super thin (about 1–2mm). Thin layers help avoid cracking and give you a beautiful, smooth finish.
Prime again and add a second coat of microcement
Once your first coat is completely dry, prime again and repeat with a second coat of microcement. This helps fill in any rough edges or tiny gaps. You can sand after the first coat, and you should if you want a super smooth finish, but I love a bit more of a textured look so only sand after the second coat.
TIP: You can always use a utility knife or palette knife to knock off any imperfections when the microcement has nearly dried but not quite. This is a technique I used on my DIY microcement breakfast bar.
Sand the surface
Once dry, lightly sand with an orbital sander (this is mine) to get it to your desired smoothness. If you need a lot of sanding, start with a lower grit (more coarse) and move down to a higher grit afterwards.
Seal the microcement
To protect your planter from the elements and daily wear, seal the microcement thoroughly, again, following the Concrete Lab instructions.
I love that Concrete lab sell a tiny mixing attachment to get the perfect mix on the two parts of the sealant as this was the hardest part for me previously! This is one of my favourite ways to get a professional finish on DIY concrete planters.
Staple in the waterproof membrane
To give your new planter the longest life possible, staple a waterproof membrane to the inside. This prevents soil and water from sitting directly against the wood. You don’t want all that moisture to compromise your hard work!
Plant Up!
Once your DIY microcement planter is completely dry and sealed, you can get planting. I filled mine with Hydrangea paniculata, but any favourite blooms will do.
DIY microcement planters for the win
This project took just a couple of days spread over two of the hottest days of the year so i was tucked away in the shade of the side of our house, and turned out better than I’d hoped. Whether you’re making smaller containers or large planters, these DIY cement planters are such a rewarding project. As you can see from the picture above, there is still much work to do in the surrounding area, but at least I have finished something now!
If you’ve been itching to try your hand at microcement this is a great way to dip your toe in. Just be patient with the layers, keep them thin, and don’t rush the drying time. you’ll be amazed by your final result!
You can read about my other microcement DIYs over in the microcement section of my blog. Where I share my DIY kitchen worktops, fridge housing unit, DIY breakfast bar and even concrete cloth decor!
✨ Don’t forget: Concrete Lab have set-up a discount code, so you can get 10% off your own microcement projects with code CDS10. Tag me on Instagram if you share any of your home DIYs.
