A Compact, Mobile Garden Planter

I needed a garden planter that was affordable to make, could be moved on short-notice, and contained enough soil to grow fruiting vegetables and tubers. The initial plan was to make the walls out of strip planks, like many of the other designs out in the world. But while wandering the aisles of the 'Depot, I discovered something that would change my plans completely!

This design is centered around the HDX 55gal storage bin, a black Polypropylene that at 3 1/2 by 1 1/2 feet, is pretty much the ideal shape for a small planter. The rest of the frame is constructed of widely available lumber and pocket screws. I've also included the design of a trellis frame that can be screwed onto the sides of the planter to support climbing vines.

I was not great at taking pictures of all the steps - but have improvised with some sketches and hand drawings where necessary. I will reply if messaged - if you do attempt to build one of these and run into an issue, please reach out!

Tools:

• Miter Saw
• JigSaw or Circular Saw
• Drill and/or Torque Driver, drill bit set
• Kreg R3 jig and clamp(s)
• Scissors
• Tape measure, carpenter's triangle (suggested), pencil
• (optional) sanding disks, paintbrushes

Bill of Materials can be found here, along with the links and prices as of the writing of this post.

As we were limited by our equipment, almost all of the lumber can be cut on a miter saw. The lengths needed can be found on the 1st page of the drawing attached to this project. We found it helpful to number the planks to keep track of them during assembly - I produced a handy sketch to keep track of their locations (as well as a cut guide which places the board lengths on standard lumber lengths).

keep your cuts clean and precise - it will benefit you down the road when you have to put them together! I found the best process to be the following:

1. precisely measure the piece to be cut and mark across the width with a carpenter triangle.
2. run it through the miter saw
3. mark this piece as the master, and use it to mark the cut line on all proceeding pieces. Don't use the other cut pieces as the master! Otherwise you'll be playing a game of Telephone with your dimensions.

The Upper Wide plank (Part "E" in my notes above) needs a cutout in it to accommodate the handles on the plastic bin. this can be cut out with a jigsaw, or a circular saw and some patience (a combination of the two will make the cleanest cut). See page 1 of the drawing for specific dimensions.

See the 2nd page of the drawing for how to assemble the five panels that comprise the planter.

The base is made of the 2x4s, pocket screwed together. follow the indicators for where to put the screws. I also produced build notes that I've shared here - they may be helpful to future builders.

you will need to build two short and two long panels. I suggest starting by attaching the tall plank to the upper plank first, as that sets the length of the panel (which should make things fit together more easily later on). For added strength, apply wood glue on the joints before screwing them together.

The long panels each have six extra pocket holes. Drill these according to the drawing pg 2, but leave them empty for now - they will be fastened later.

Put the panels together! I've drawn a (pretty terrible) sketch that shows the process I followed.

1. Lay one of the Long Panels on a flat surface.
2. Apply wood glue along one of the sides of the Long Panel, for a stronger bond. Place one of the Short Panels in position, and clamp it to the side of the long panel. It should be flush with the work surface, and flush with the top/bottom edges of the Long Panel.
3. Install the pocket screws into the Long Panel/Short Panel, tighten them to desired torque* and remove the clamps.
4. install the base panel into the right position - it should be mounted vertically, flush with the bottom edges of the two panels and flush with the un-fastened side of the Long Panel. clamp it to the Short Panel to prevent it from falling over.
5. repeat steps 2 and 3 for the other short panel. If there's a gap/not enough space for the base panel, you'll need to add some shims, or remove material to make it fit (that one's on you, buddy).
6. Tip the whole assembly upright, so the Base Panel is on the work surface. Put glue along the top edges of the Short Panels, and clamp the remaining Long Panel to the short panels, making sure it fits into place. All edges should be close to flush.
7. install the final pocket screws and remove the clamps. Marvel at how close you are to completion!
8. Take the drill and a 3/16" drill bit, and drill pilot holes along the bottom of the assembled frames (see drawing for specifics). screw 2.5" wood screws into the base panel to lock it in position.

Great work! Put the bin in to make sure it fits .at this stage, if you are happy with the fit, you can "finish" by sanding and staining/painting the frame. Typically, you wouldn't want to put paint onto a vegetable planter due to compounds leaching into the soil. But because the soil and the flora is contained in the Polypropylene bin, it is "probably safe" to use PolyUrethane or any other waterproofing on it. I like the weathered look of our unfinished planters (visible 1 year later in pics on page 1), but you may find the lifetime of the planter is lessened with no finish.

*note: the torque you tighten them to is dependent on the lumber and the specific grade of wood screw you use. The best method to determine this is to drill a test pocket hole on some scrap lumber, and trial/error it with your drill until the ideal torque is found. the wood should be pulled flush such that there is no gap, but the fastener shouldn't "start to give".

This is where things start to diverge, depending on what you want to do.

Swivel Wheel Configuration:

1. place the wheels in the right locations (I've suggested a location in my notes as well as in the drawing), and mark the holes.
2. Drill more 3/16" pilot holes into the base.
3. Install the hardware of your choice to hold the wheels in position.

Fixed Feet Configuration (untested):

This configuration uses 4x4 Douglass Fir lumber to make feet.

1. Place the feet on the work surface (or the floor) right-way up, and then place the planter frame on top of them.
2. measure from the outside of the planter (see drawing) to set their positions, and slide them around until they line up.
3. Keep pressure on the frame to keep things from sliding around. Drill some 3/16" pilot holes through the Base Panel members; it doesn't matter much where they go, as long as they avoid the fasteners we installed earlier.
4. Screw in 3" wood screws through the Base Panel and into the feet.

Center Wheel Configuration (untested):

This configuration uses 4x4 Douglass Fir lumber, as well as a caster, Tee nut, and threaded foot from Mcmaster-Carr. The part numbers for these parts are given in the drawing, page 3.

1. With the planter frame upside down, locate the wheels in the correct locations (see drawing). Pre-drill holes with the 3/16" bit, and install using the hardware of your choice.
2. Hammer the T-nuts into the Foot block, they should sit flush with the surface.
3. Flip the frame over, and place the foot block in roughly the right location. Measure from the far end (see drawing) and adjust its position
4. Keep pressure on the frame to keep things from sliding around. Drill some 3/16" pilot holes through the Base Panel members; it doesn't matter much where they go, as long as they avoid the fasteners we installed earlier.
5. Screw in 3" wood screws through the Base Panel and into the feet.
6. tilt up the planter frame, and install the leveling feet.

I did design a trellis for these planters - I don't have as much documentation for the build process, however it's quite similar to the rest of the planter. Cut items as shown in the cutlist drawing , and assemble with normal wood screws - I believe 1 1/2" works for everything. I've attached my work notes, but do NOT use the dimensions! they are incorrect.

The trellis screws in place on the Short panels of the planter - use <=1 1/2" woodscrews or risk puncturing the bin! I added two extension panels, hinged on Everbuilt 259792 hinges - but feel free to use any hinges that fit! I then stretched a grid of hemp twine across the frames , and added some trailing strings into the bin, to be buried when soil is added.

• Drill some drainage holes into the bottom of the bin - I used a 1/2" bit
• Add soil - I found that 9-10 cu ft fills it up decently well. To reduce the weight (as a full planter can weigh several hundred pounds with moist soil!!), add perlite generously to reduce the soil needed. You can also add lightweight compost, such as shredded paper bags, leaves, etc. Make sure you know & trust the source of these materials, to ensure you aren't adding any herbicides/chemicals to your soil.

And that's just about it! You're ready to plant. I hope these instructions were helpful and have provided you with a sturdy planter to last you quite a few seasons 🙂