I live in an apartment with fairly big balconies, nevertheless, I'm always trying to get big planters suitable for my space and I came up with this easy solution. (Which also happens to be cheap)
It's a planter. Made out of a box. Easy as.
Step 1: What you'll need...
-A wooden fruit box. (You can go to the market, ask nicely and they'll just give them to you)
-Any type of plastic. (I used a black thick plastic sheet I had at home, but plastic bags would work as well)
-Staple gun (+ staples, d'uh)
-Plants, seeds, cactus or any type of plant or veggie you want to grow.
Optional--> Give some color to your box!
Just paint your box any color you want. It doesn't have to be perfect, just have fun with it.
(Remember to use some newspaper under it to prevent paint stains)
Step 2: Box + Plastic = Love
Then cut another piece of plastic to cover the bottom.
This will prevent the soil from escaping and will also protect the wood from rotting by getting in contact with water and humidity.
Step 3: Make some holes!
So go ahead and with the tip of your scissors, or a pen, or anything you find lying around, poke some holes to the bottom of your box. The bubblewrap-like sound of the plastic satisfies the soul.
Make sure to perforate between the planks to help drainage...
Step 4: Now, for the fun part...
If you're going to work with cactus, please be VERY careful, wear gloves and use some folded newspaper to help you handle the plant.
Soooo, start filling your planter/box with soil and plant away!