Green Wall Construction 101
October 2013
Post by Mariah Gleason and Amanda Beck
Mariah is a graduate student, pursuing her Masters in Urban and Environmental Planning at the University of Virginia.
Amanda is a graduate student in Urban and Environmental Planning at the University of Virginia.
While the Biophilic Cities Team was preparing for the LAUNCH, we wanted to make sure that the exhibit also included a taste of the innovative green ideas that exist throughout our partner cities. We decided to include an array of options for our green demonstrations, from do-it-yourself to store-bought and assembled kits.
In the end, the Biophilic Cities Team decided on five different green displays for the LAUNCH. We had a living terrarium (bought), two planted hanging frames (kit), a succulent frame (kit), a moss frame (DIY), and our big DIY project – a rolling, double-sided, vertical, indoor pallet.
As this is our first time attempting a pallet project, we thought we might share with the BC family the process we took to develop our one-of-a-kind garden, as well as some of the lessons we learned along the way. Follow along to see how you can create your own vertical pallet garden.
Materials
2 wooden shipping pallets with similar dimensions [Note: Treated wood pallets will have an “HT” or “CT” marking on two opposing sides. We suggest using “HT” or heat-treated pallets rather than “CT” or chemically-treated pallets because they can be harmful for plants.]
¾“ Plywood, any type : 1 piece that measures 10” longer AND wider than the footprint of your two pallets (for the base) and 4 pieces that measure at least 3” x the width of your combined pallets (for attaching the pallets together)
2×4 : 2 pieces cut at length of the plywood base, and 6 cut at the width of the base MINUS 3” take into account the width of the 2 length boards
4 swivel casters, or attachable wheels, to make the pallet roll
4 large L-brackets
1” and 3 ½” Screws and Washers
100ft roll of landscaping fabric [Note: We used a fabric that was water-retaining, but water penetrable landscape fabrics should also work.]
Approximately 4-32 quart bags of potting soil [Note: We choose potting soil because it tends to retain water longer, thus keeping our plants hydrated between waterings. We also choose it because regular soil can get very muddy when watered so we wanted to make sure that whatever soil we bought wouldn’t wash out of the pallet and onto the building floor since our pallet was going to be kept indoors.]
Plants – we planted 4 per row on each side
Flexible, aluminum air duct or similar water-catching structure to fit in the pallet base
Tools
Hammer
Chisel and mallet
Palm sander with sandpaper – we chose 100 grit
Measuring tape
Scissors
Staple gun & heavy duty staples
Cross-cutting saw and table saw
Clamps
Power Drill with appropriate bits and heads [Note: This is the most powerful tool in your arsenal. Our team learned that a good, fully-charged power drill can solve any problem this construction project may surprise you with.]
Hacksaw
Friend
Construction
Phase 1: Preparing the Pallets
Some pallets are available commercially and already safe for handling; however, our pallets had been used and therefore needed smoothing for safe use. No splinters are good splinters in our opinion. Also, remember to wear your personal protective equipment!
To prepare the pallets, use a hammer to completely nail in any nails still sticking out slightly. Aim to have them flush with, or beneath, the wood face.
Use the chisel and mallet to rid the pallets of any large splinters of wood that have pulled away from the larger wooded frame. A file will also work. This step will save your sander later on.
Sand all of the surfaces of the pallet that will be handled during the life of the pallet.
If your pallet is going to be attached to the base structure, chose which end of each pallet will serve as top and bottom. Remove the back, bottom board from each panel. This will be the area that your water catcher (the flexible air duct) will be placed. Story: During our construction, we thought we needed to remove all of the base boards from our pallet, excluding the one that would serve as the front of the display, so our water catchers could be easily removed and replaced from the pallet. As we discovered, you only need to remove the back, bottom boards for the drainage system to be accessible. Thus, as pallets are built to never come apart, we recommend not having to pull off any more boards than you need to.
Take the landscape fabric and cut it into 10″-12″strips. These will serve as the pockets for the plants to fit in within the pallet.
Fit the long edge of the fabric strips right below the backside of each front-facing horizontal board, leaving about two inches of extra material on each end. Cut excess fabric off. Staple the fabric in place. [Note: You will need to use two strips per row because the vertical board along the spine of the pallet essentially cuts each row in half.]
Take the free long edge and flip that edge up, allowing the fabric to form a pouch or pocket. Place the fabric along the inside of the horizontal back board at approximately the same level that the front edge is stapled. We recommend having extra fabric on either end of the fabric strip in order to help the fabric easily stretch to the back of the vertical boards if there are no horizontal back boards to attach the fabric to. Staple into place.
Tuck the extra fabric on the end of each pouch towards the inside of the pouch. This will help keep the soil in place when the pallet is planted.
Phase 2: Building the Base
This phase is optional, but recommended if your pallet garden will be kept indoors, and/or you want it to be mobile.
Set your frame. Place the two long 2×4 boards parallel to one another. Use two of the short 2×4 boards at each of the ends while placing two additional short 2×4 boards at equal intervals within the frame. Use the clamps, or a friend’s help, to drill two 3½“screws into each joint. This will secure the boards in place. [Note 1: You may want to create pilot holes before screwing each screw into place. This step makes the whole process easier and prevents the wood from splitting.]
Flip the base over and use the 1” screws to attach the plywood to the base. For maximum structural integrity, use two screws at each end of the board and at every 6”-10” along the board’s length.
Take the remaining two 2×4 short boards and place them wide face down within the frame, towards the ends of the base. Place two casters towards the end of each board, making sure that when placed within the base, they will retain their full range of motion. You may want to put a washer beneath each screw to insure that the wheels are as secure as possible.
Screw the boards into the base structure. [Note: We chose to use some additional pieces of 2×4 within the frame to make sure the base was extra secure, however, this is not necessary. Drilling a pilot hole is optional for a screw this length.
Phase 3: Putting it Together
Standing the pallets vertically and back-to-back in the desired way, use the four small plywood pieces to secure the pallets together. Use two pieces for each side, one towards the top and another towards the bottom.
Place the pallets in the center of the finished base. Secure the L-brackets on the inside of the standing pallet structure.
If using the air duct as a water catcher, use a hacksaw to cut the duct in half. There are other options for water catching devices, we simply chose the air duct because it fit the dimensions of our pallet base and would not rot over time. Place the air duct in the base of the vertical pallet structure, fanning the sides up along each end.
Plant your new vertical garden pallet!