Cement Planters: A Gray Area

I’ve been plotting to make cement planters ever since I saw them detailed in the late ReadyMade magazine earlier this year.

Graphic designer for Exhurb Magazine, and author of simplysofie.com, Sofie Sausser sung their au-natural material praises as she outlined the how-to that was featured. And I was impressed.

Her designs asked for small recycled plastic containers (think: leftover from your every day yogurt, sour cream, cottage cheese, or worn out tupperware) to act as forms for the cement to cure within, but I was hoping to kick it up a notch and create some larger planters. Specifically, one for that large, leafy tropical plant I lugged home last month. And some larger ones for other plants to be transplanted into. Because I always seem to be outgrowing my collection of planters.

I’ll tell you upfront that this wasn’t as easy on a larger scale. In fact, it was damn close to a fail at times. Read on to understand why, but first, take this sneak peek of the final project. And oohh, aahh, nice.

Want to know how I did it (and why I self-categorize it into a gray area on the success scale)?

I save almost every random plastic planter and bucket that falls into my hands, so I had a good selection to choose from. For my flagship run, I went big, using a large black plastic container to serve as the outer edge of the planter mold, and carrier of the cement. Because I needed a smaller bucket for the inner part of the mold to create the form that the plant would eventually be planted in, I used a 5-gallon pail (that white one in the background of this photo. Before I could do anything though, I had to seal the black container base, as it was constructed with built-in drainage. I imagined at first that this wouldn’t work, but it did.

Duct tape was the problem solving material, and stayed really well put throughout the whole process, even considering that I mixed the cement directly in that bucket with a small pointy-ended, hand-held, gardening rake that you’d immediately imagine puncturing the tape in a swift motion. It was Extreme Home Cement Mixing – DIY Edition.

I did bring home a 94-lb. bag of portland cement for the project, which was the variety that Sofie had used and recommended (although I have noticed other people doing these projects and using whatever cement they wanted). I had never worked with that variety of cement before, but can attest to it’s texture being more like soft flour rather than rocky or gravely cement that I’ve used in other projects (like installing deck posts).

The bag was just shy of $10, and I imagine that it’d make about 3 large planters, or 5,000 small planters like Sofie has perfected. OK, 5,000’s an exaggeration, but it would go hella far. (I should also note that I would have bought a smaller bag if I could, but this is all they had at our Home Depot).

Pete gets full credit for carrying to and from the car and stashing it off the ground in the shed, which is exactly where it stayed for a week as I mustered up the energy to get started. Concensus? Concrete seems like it would be a pain in the ass, but it’s really not bad at all. Plus, it’s always a race against the clock since it begins to cure so quickly, so the project is practically over before it begins. Did I just sell you on it?

To begin to mix the concrete, since I couldn’t lift the bag myself (which I suppose is the huge deterrent for getting started). Because the bag was off the ground (balanced on two chairs), I tore open a corner and began scooping it into the black container slowly.

I mixed water and alternated adding more cement, adding more water, adding more cement until the mix (as Sofie put it) was the texture of peanut butter.

I do not have an exacting formula for you, just know that if you use more water, it will take a little longer to dry.

I mixed it right in place rather than in a different container for simplicity, and used a small gardening trowel and rake to make the consistency smooth and lump-free; the rake acted like a whisk and broke up all chunks, just like if I had been beating cake batter. I was also continuously checking how the height of the planter walls would be by squishing the 5-gallon bucket into the mixed cement until it was the height I had envisioned (anywhere between 9-12″ tall).

Once it was ready to be set for drying, I loaded the 5-gallon bucket with bricks to hold it deep into place, and used some duct tape as reinforcement to keep the bucket balanced upright while the cement began to set. Without the tape, the bucket and bricks were bobbing in the cement a little, tilting to the site.

You can see in this next photo how I forced the white bucket all the way to the bottom of the black outer bucket to help figure out how thick the bottom base of the planter should be. Because the wet edge of bucket sticks about 1.5″ above the level line of cement, I knew that the base would be 1.5″ thick.

The good thing about portland cement, I found, was that it wasn’t as bloated with air bubbles as other cements I’ve worked with. I did tap on the outer edge of the black bucket before it set, but I didn’t shove a narrow stick down into the walls of the planter, and still didn’t end up with obvious air bubbles.

Turn the clock 24-hours forward. The cement was set, and I was ready to separate it from the mold. This is where it got tricky.

Because the plastic containers weren’t lubricated with anything like vaseline or Crisco, that cement was sealed in there pretty well. Zoink.

This is where I wish I had more photos of myself, because while I started by gently and cautiously tapping the outer bucket with my palm, I quickly transitioned to blasting it with a hammer and launching the whole piece medicine ball-style with my big ol’ work gloves on for grip. While it seemed to be loosening along the visible edges of plastic, there was no budge. But I was getting a damn good workout. It was 30+ pounds of cement plus buckets, after all. Muscles, baby.

For about a half-an-hour (yes, that long, and I wonder if my neighbors were watching), I forced my hands against the plastics, dropped it upside down, jumped on it, rolled it, launched it, and pulled on it. There just came a point where I figured it would never come out, and was trying to salvage the buckets by holding the whole thing above my head WWE-style and shot-putting it a few feet in front of me into the yard, where it landed hard, digging into the grass. I was never great at shot.

Suddenly, the white bucket popped loose like it should have been extracted simply all along. Kind of like when you try and open a jar of banana peppers for 3 minutes and then ask someone else to try and they break the seal in .0025 seconds. What can I say? I was surprised. And felt accomplished. Notice how cracked the white bucket became after several hard encounters with earth.

Removing the outer bucket was a little easier once the inner bucket was out of the way. I bashed it against the ground upside down a few times and hammered against the bottom until I felt it slide loose.

Of course, considering the brutal knock-down it had been enduring, it slid loose in pieces.

And not that it’s overly significant, since the rest of the planter was in shambles, but nice chunks of cement did adhere to the drainage holes that I had taped up. I wish that hadn’t happened.

About half of it had loosened, but the other half was still in tact, including most of the base, so I brought it all inside to try and cure the situation with some glue.

I do know enough about cement that patching it usually involves using more cement, but Pete’s a big collector of glues, epoxy, and generally mega-strong adhesion formulas, so I tapped into a half-empty (or half-full, since it was enough to complete what I was going for), tube of the crafty and strong E-6000 (the same stuff that’s saved my IKEA drawers and Pete’s Aluma-wallet).

 The salvaged pieces did fit together pretty easily and, more importantly, evenly, so I gave it a fair shot at living by reinforcing the pieces while the glue dried with blue painter’s tape (since unlike duct or masking, it wouldn’t leave behind a residue on the smooth planter). It was (and is) super smooth to the touch, by the way. I love me that portland cement.

I also smushed the E-6000 into each crack along the inside of the planter in hopes that it would help out. It seems to have acted like a water barrier of sorts, and I’m interested to see how it holds up.

After another day letting the glue dry, I was daring enough to fill it up with potting soil and transplant the big, leafy, happy plant into it’s new home. And freshly watered it. Curious if the glue will hold up; I really have no way of knowing.

Notice the chips in the base? That’s from the holes in the original black container. Even though I taped over them, the cement latched on to remaining ridges and didn’t come off smoothly.

It’ll stay on the deck for a few days for two reasons:

1. The cement is sure to absorb moisture from watering the plant, and I don’t want that moisture seeping into the hardwoods (I need to find a large tray or something for it to sit on);
2. Hello, it’s glued together with E-6000. I half expect it to crumble overnight. Bets on how long it lasts?

P.S. Started working on a smaller one just this morning. Sneak peek? If you can tell, this time I’m using more malleable black plastic 3-gallon containers that Home Depot plants come in. I’ll share a photo update Sunday on the facebook page. I’m cautiously optimistic. Have a cool weekend.