I think this might be of interest to anyone who is following this thread. This was initially posted to the thread
Show Me Your Pallet Projects, but it works equally well here...
Easiest Raised Garden Bed Using Only One Pallet!?
Just came across this YouTube video on how to make a raised garden bed using one free pallet. She cuts a pallet into 4 pieces and screws them together to get a basic 4X4 foot raised bed which I am guessing is probably 10-12 inches high. I think this is a project just about anybody could do with minimum skills, minimum tools and minimum cost.
So, check out the video first...
A few of my thoughts...
Instead of buying weed block material to line the sides of the pallet to keep the dirt in, you could probably make good use of those chicken feed bags you have laying around. Especially if the bags were made out of some kind of plastic material. I would not put down a waterproof material on the ground because you still want good drainage in this design. But those chicken bags would be great for the sides to hold in the dirt.
You could call the project done at that point and be totally happy with the build. Minimal effort with maximum payback. Her goal was to make an inexpensive garden bed that would last at least a few years. I think she met that goal.

If you are like me, you might be thinking what else could I do to this build?
As to the outside of the pallet raised beds, if you wanted to add a little extra to the project, you could put a board underneath that top open gap and put small planters around the outside of the pallet raised bed. Something like this...
Or maybe just put the board underneath that top gap and just fill it with dirt to grow some shallow root plants.
Another option would be to add some trim boards to the top, making it comfortable to sit on the wall/edge. I don't do that on my raised beds, but I know some people like the looks of the trim boards and/or need a place to sit down and relax while they tend their garden bed. The trim boards on top of the raised bed would look something like this...
If you don't like the looks of the open boards in the pallet raised bed walls, you could use a simple board on board method to cover the open gaps. Like this...
I built that for a storage rack top just to keep most of the rain and snow off the wood stored inside the rack. But that same board on board method could be used to fill the open gaps on the side walls of a pallet raised bed if you don't like the open look of the pallet.
None of my modifications would have any effect on the plants growing inside the pallet raised bed, but I know aesthetics can be a big issue for some people. So, I thought I would offer some thoughts that you might want to consider.