My wife found a picture of a planter box made from pallet wood online and said "I want one!" So, with inspiration from that web site, I made a very inexpensive version my own way.
(2) 2"x4"x8' studs (about $1.50 each)
(9) 5.5" wide, 6' fence boards (about $1.50 each)
Hammer & nails or nail gun
drill & 2" hole cutting bit
Step 1: Cutting the Legs and Sides
For a box my size:
From the two 2x4s cut four 40" lengths to serve as the legs and frame for the box.
Cut three of the 6' fence boards in half to make six 3' lengths.
Nail those 3' fence boards to the 2x4s, three boards each per two legs. This completes the side panels.
Cut two 16.5" lengths of fence board, and use those to space the side panels apart by nailing them to the inside edges of the legs of each side panel, 1/4" above the bottom edge of the side panel boards (see video for clarification if needed) which will connect the two sides. Now stand the box upright.
Now measure the distance between the 2x4s length wise, and cut three sections of that length (for me it was 33 inches) and use scrap wood to hold them together side by side. place those boards inside the box to make the box bottom. Nail them in place, at the ends and along the sides. Use scraps to cover the two gaps at the ends of the box bottom, between the 2x4s.
measure the ends and cut six more pieces of fence board to match, and nail them to the 2x4s
Now with the remaining fence boards make a small box to place inside the bigger planter box. This small box will create a void so soil wont be wasted as filler. It also decreases the weight and overall stress on the box.
My "viod" box leaves the width of a pallet board all the way around and on top, for dirt....so 5.5 inches around.
Now, measure and mark where you want your holes. I spaced mine about 6 inches apart side to side, and staggered them.
Use a drill and a 2" hole cutting bit (or a method of your choice) to make the holes.
I ended up with 44 holes total, 17, 17, 5, & 5.
Step 3: Plant the Flowers
We planted Wave Petunias.
First, place your planter box where you want it to stay upon completion.
Add dirt around the void box up to the level of the fist holes, then gently shove the roots of each plant through the holes from the outside.
Fill in more dirt, pressing it down around the roots, and sprinkle water. Continue filling to the bottom of the next level of holes, and repeat.
Repeat for the third level, then fill the box the rest of the way.
Finish it by planting flowers in the top surface.
Step 4: Watch This Video to See It Being Built As Described.
This a quick and easy project that anyone can build, and is pretty as soon as it's done. When the petunias fill in and flow, it will be spectacular!