Create your Legs: Use your Table Saw with a Dado Blade to create a 3/4” x 3/4” Dado on two adjacent sides of each leg as shown below. You can also create these grooves using the table saw without a dado blade, by simply setting your depth to 3/4” and running your post across it a number of times until you have a 3/4” groove. You can also use either a circular saw, or jig saw by setting your depth to 3/4” and running it along your post a series of times in a row until you have carved out a 3/4” gap. A router with a straight bit or one part of a mortise and tenon bit will also work! The first image shown below is for corner legs, if you want to make this planter longer, you will need to add a center leg which should be constructed as in the bottom image for this step. **See the instructions section above for a note on adjusting the size. I recommend burying each leg 6” to add stability to your bed. Each leg is sized in order to allow you to place your legs 6” below ground level and with 4 panels, but if you prefer to have the bed sit on top of the ground instead simply subtract the 6” from the length of your leg, and if you prefer to shorten the height of the bed overall, you can subtract that from the size of the legs as well. The portion of the leg sitting above the ground should be exactly the same dimension as all of your panels combined regardless of whether you choose to use 2 or 4 or 6. The number of panels you choose to use for your height can be determined by aesthetic or if you live in a very cold climate you may need to go a bit higher to account for the frost layer.

Leg Layout: The diagram below shows the layout of the legs once you have created your grooves, the blue legs show how the center legs will sit if you need to increase the length by adding center legs. You can pull out the spacing between your legs as many times as you need, and add a center leg any time the length exceeds the length of a fence board.

Attach the Side Panels: Your boards should be pretty snug in a rug in your grooves and you may need to pound them down into place using a mallet. We are not going to secure these using nails or screws so that at the end of the growing season you can pop the panels out and store your bed away or so that you can adjust the size of the bed easily when needed. Since this will have an open bottom, you have no need to secure this any further than the legs already will by holding the panels in place with your groove. To adjust the depth of your bed, simply increase the legth of these panels. If you plan to go longer than the length of one fence board, you will need to add center legs as seen in Step 1 and then double up the number of boards per side. If you want this to be 100” for example, you will add a center leg and then you will have 2 columns of 50” panels.

Attach the Front and Back: Do this in the same manner you did for the sides, use a mallet or something to hammer them down into place and add center legs if you need to increase the length of your bed beyond the length of one fence board.

Add the Top Trim: Miter the corners for the most professional appearance and secure to the front, back, sides, and legs using nails or screws. If you adjust the dimensions of your adjustable raised bed, just adjust the dimensions of the top trim by ensuring the the inside opening as shown below at 31 1/2” x 56” is equal to the inside opening of the bed as measured from the corner or one leg to the corner of the adjacent legs in either direction. If you increase the overall dimensions of your bed by 10” in both directions, the interior opening will also increase by 10” in both directions and so your measurements would adjust to 41 1/2” x 66” for the opening and 52 1/2” for the side top trim and 77” for the front and back top trim.