What you’ll need: shipping pallet, 4 mounting brackets* (one for each corner of the pallet – we used L brackets), weather resistant screws, roofing nails or staple gun, drill, level, weed cloth (aka landscape fabric), thin plywood cut to size to cover back of pallet, potting soil, plants (*when it comes to how and where you choose to mount your pallet, make sure to consider the weight of a fully-planted pallet after watering and choose the appropriate hardware and location that can support it.)

Pallets are everywhere, so take the time to find one in good condition and that is not made from pressure-treated wood (due to the leaching from potentially harmful chemicals). They come in different shapes and sizes so don’t assume all pallets are the same. Make sure it’s cleaned off and you’ve inspected it for any stray nails or splintered wood. It’s a good idea at this point to wear a sturdy pair of gloves while inspecting and cleaning the pallet.

Once the pallet is cleaned up and before you add any additional weight to it, go ahead and position it against the wall where you’ll want it mounted. Use the level to ensure proper alignment. Make your marks and install the L brackets to the wall. (Once the pallet is planted out, you’ll then simply slide it into place between the mounted brackets.)

Return the pallet to a flat surface. Although you could plant out your pallet with it resting on the ground, placing it on a tabletop or sawhorses makes it easier to work with from a standing position. Place the pallet so that the side with the widest openings is facing up. This will be the backside, which you’ll mount against the wall. Lay out the landscape fabric or cloth to cover the back and bottom and cut to size. Pull tautly and secure with nails or staples. Some pallets have wood covering the bottom of the pallet, which will help prevent soil from falling out the bottom. If not, you may choose to add another piece of wood, like a 2×4. But in either case, make sure the fabric covers the bottom as well as the back to catch any soil that may otherwise fall out. This would also be the time to add a thick layer of plastic or other waterproof barrier. This step wasn’t included in the DIY segment on the episode but this is an important part of protecting the exterior of the house from the moisture and grime of the pallet garden.

Next add the thin plywood over the cloth and/or plastic and secure.

Now turn the pallet over and fill with good quality potting soil or container mix. Don’t use ordinary garden soil or soil that is designed for planting beds, as it’s too heavy and won’t drain as well. Be sure to add most of your soil before adding the plants. Now, go ahead and tilt the pallet up nearly vertical to allow soil to settle without it spilling out between the cracks. Then continue to add soil until the pallet is full.

Next add the plants. Don’t be afraid to pack them in. Position the plants so their root balls are securely placed between the slats and tuck them in firmly. Once you have all your plants in position, add additional soil if needed but be sure to reserve some to add once the pallet is mounted. Don’t water yet due to the added weight.

Now it’s time to mount the pallet. Get two helpers and position the pallet between the brackets already secured to the house. It’s helpful to have something to rest the pallet on while it is being secured to the wall. With helpers holding the pallet in place, the third person can attach the brackets to the pallet.

Finally, make sure all the plants are positioned firmly in place and that the roots are in good contact with the surrounding soil. This is also the time to add the reserve soil to fill those voids. Thoroughly water the plants and soil. Again, you’ll have more settling and some soil loss here so have some extra soil on hand and add as necessary.

Over the next few days, continue to monitor the garden and add soil and water as needed as the plants establish and soil continues to settle. Once the roots fill out in a couple weeks, then just make sure to keep it watered. Because this garden is above ground, it will dry out more quickly. Like other containers, daily watering is likely.

Enjoy the harvest!

Watch the full episode this project came from, Episode 221: Living Walls.

Special thanks to our friend Fern Richardson at Life on the Balcony, for her Pallet Garden plans.

Update: 4/3/12: Last week while touring the floriculture Pack Trials in California, I saw a modification of our pallet garden: Burpee Home Gardens added simple feet using triangular pieces of plywood.

I love it because it offers so many more options, especially for those that want a vertical garden against a wall without having to attach it to the wall, and it alleviates the concerns some folks have brought up about (potential) damage to the wall from the pallet’s (potentially) moist backing. Plus you can put it anywhere! Simply brilliant! – Joe