• >= 3/4" stepped drill bit and drill
• reciprocating saw (like a sawzall) with a metal-cutting blade
• 55 gallon steel drum
• spray paint and primer (light color preferable)
• 30 gallon fabric grow bag (24" diameter) (I used this one http://a.co/bXsg4By)
• 4' x 4' sheet of strong impermeable plastic (I used this pond liner https://www.lowes.com/pd/smartpond-500-Gallon-Blac...)
• 2 cubic feet of landscaping lava rock
• One leg from a pair of old torn blue jeans
• about 4' of 1/2" diameter PVC pipe
• 2 PVC pipe elbows for the 1/2" pipe
• PVC primer and PVC cement
• 1/2" diameter PVC threaded (one male and one female) adapters.
• Small piece of plastic sheet about 1/4" thick, to drill a 3/4" hole through to use as a washer.
• 4 cubic feet of good, fertile potting soil
Step 1: Cut Your Drum Down to Size and Clean It Up
Set your drum upright with the bungs accessible on the top. If your drum has any oil residue in it, leave it sitting in this position for at least a few days so that all oil pools in the very bottom.
Using your saw, cut the top about-1/3 from the drum where the reinforcing ring goes around it.
If your 55-gallon drum has any oil residue in it, drain all of the oil that you can out, and then carefully clean it, inside and out, in preparation for painting. You need to remove all traces of the oil residue and any rust and dirt, or your primer and paint won't adhere to the drum well, and it will rust out pretty quickly.
Apply your spray primer and spray paint well, all over both the inside and the outside of the drum. It's important to make sure that you get a good paint job, since that will be a big part of weatherproofing the planter.
Step 2: Install the Plastic Liner.
Fit the liner carefully into your empty drum. Having cut my liner material to exactly 4' x 4', I had each corner come to just above the cut rim of the drum when it was laying flat and centered inside the drum. I applied glue to each corner and used clothes pins to hold them in place while the glue dried.
Step 3: Water Input Pipe Assembly
Cut some lengths of PVC pipe: 24", 18", 6".
Using the elbows, assemble these pieces so that you have the 24" portion standing upright, connected to the 18" portion extending out along the ground, and the 6" portion extending out perpendicular, so that you have a stable "foot" that it rests on when completed.
Use the PVC primer and PVC cement for final assembly. Allow this to dry for 24 hours.
Drill drain holes along the 18" and 6" portions.
Place this into the bottom of the planter with the 24" portion standing upright. It should be a few inches higher than the top of the drum.
Step 4: Install Wicking Material and Gravel
Lay your leg from the old blue jeans in the bottom, across the water-fill pipe.
Put a scoop of the lava rocks in the middle of the blue jeans, and then fold either end of the leg over those rocks in the middle, like a burrito.
Fill in more lava rocks around the outside, then when you've put it all in, unfold the ends of the legs back out to the sides, and make a level surface on the lava rocks.
Step 5: Place the Drain Hole
Clear away just a little of the lava rocks where you'll place the drain port.
The exact height of the drain port should put the lowest point from which water can drain out about 1" below the level surface of the top of the lava rocks.
Drill through the drum at the height required, and make a hole in the liner that's just big enough for the PVC fitting to go through without leaking into the space between the liner and the inside of the drum.
Push the male threaded PVC fitting through the hole from the inside to the outside.
Take a small piece of plastic, about 1/4" thick, and drill a hole in it, to make a washer to fill the gap when you tighten the parts of the drain up.
Put the washer on, and put the female threaded PVC fitting onto the male threaded PVC fitting and tighten it down until the inner fitting is making solid contact with the liner inside the drum and will form a waterproof seal.
Step 6: Drop in the Grow Bag and Fill With Dirt
Pour 4 cubic feet of potting soil into the grow bag.
Add water in the fill pipe until some water starts to come out of the drain.
You should be all set to plant some nice crops in your planter, now!