Lots of things I thought would work didn't and my first go around was not 100% satisfying, but I got it to work the next time around.
My box size was 9 bottles by 7 bottles (28 bottles total) and measured about 26 inches by 22 inches.
Note that I will not be growing edibles in this box. The combo of pre-treated wood, plastic and food.... not a good idea.
Step 1: Supplies
Plastic Bottles!! Heavyweight is good.
Pen or pencil.
Paper for writing down measurements and for funneling soil into the bottles.
Wood - 1"x 3", two pieces as long as the length and two pieces as long as the width PLUS 1-1/2 inches.
Drill and bits (to drill pilot holes for screws)
Hardware cloth or screen (to fit size and shape of your box)
Landscape cloth or weed barrier (to fit size and shape of your box PLUS add about 2 inches all around).
Wood screws - quantity: # of bottles x # bottles (long enough to go through the width of your wood and penetrate at least 1/2 inch into the plastic bottle), and eight 1-1/4" wood screws to hold the sides of the frame together.
Screwdriver, a cordless power drill makes life a LOT easier.
Measuring tape and/or ruler
Plastic bottles all the same type. 32 (or any other even number, depending on the shape and size you choose).
Soldering iron that you don't mind messing up to make drainage holes (you can use a drill instead or heat up an ice pick)
Wire (my project used less than 50 feet). I used 20 gauge copper because I like the patina, the slugs don't like it and I thought I had some on hand, but I didn't.
Slim piece of sturdy (non corrugated) cardboard or a spatula (to tuck landscape cloth into crevices)
Potting soil appropriate for whatever you are going to plant and little stones for drainage.
Plants, seeds, cuttings...
Step 2: How Many Bottles?
Decide on the size and shape of your box. Measure the area where you plan on putting the box to make sure it will fit.
Gather your bottles.
Line them up in a straight line. It is easier and more accurate if you line them up against the wall or other stable vertiical object.
Count how many bottles you need for the length and how many for the width of your box. Add the numbers together.
Multiply by two.
That is how many bottles you will need.
Step 3: Peel Off Your Labels.
This is easier to do now than after you have all of your bottles attached (as I found out the annoying way).
Step 4: Make Your Drainage Holes in the Bottles.
You can actually do this anytime before Step 15.
Heat up your soldering iron (or you can use a drill).
And melt holes in the bottom of each bottle. I made six holes in the bottom since the bottle manufacturer was also so kind to give me some guides to follow!
Do this for all of the bottles you will be using.
Step 5: Measure the Circumference of Your Bottle.
Why? to jump ahead, you will be wrapping your wire around each bottle. The bottle manufacturer conveniently made some ridges and indentations JUST for this very purpose!
Wrap a piece of wire (or a string) around the indentation that you plan on using to connect all of your bottles together. It should be about an inch above the bottom. See Step 7 for connecting your bottles.
Mark the point where the string meets the end and completes the circle.
Measure the length.
Step 6: How Much Wire to Cut?
Multiply your circumference times the number of bottles on a side and add six or so inches, just in case.
Two sides of my box will be 9 bottles wide so I cut two pieces of wire each about 87 inches long. See calculations in the photo.
The other two sides will be 7 bottles wide so I cut two pieces of wire about 69 inches long. (7 x 9 = 63; 63 + 6 = 69)
You should have four pieces of wire.
Step 7: Make Your First Two Sides. I Call Them Snakes.
I find it easier to work on the ground and use my feet as clamps.
It doesn't matter if you start making your short side first or your long side first. I chose to make the longer side first.
Count your bottles that you will need for this side and the side opposite.
Bend the wire in half, but don't crimp it. Keep it in a nice curve (like where you will wrap it around your bottle).
Loop over the bottom of the first bottle, get it in the groove, and twist the wire snugly around, and spread the wires apart.
Put the second bottle next to the first and wrap the ends around the second bottle ending with a snug twist, continue with the third bottle and so on, until you reach your last bottle.
Make an extra twist and bend the ends of the wires toward the mouth of the bottle so they won't poke you.
Repeat from "Bend the wire..." for the opposite side.
And now you have two Snakes.
Step 8: Attaching the Sides.
Separate the remaining bottles in two batches.
Fold your wires in half, keeping the curve at the end.
Take one of the finished Snakes.
Loop and twist one of your wires over the bottom of the end bottle of the Snake, again using the indentation a guide.
Put one of the loose bottles next to this one and twist the ends around the second bottle, continue with the third bottle and so on, until you reach your last bottle and make your twist.
Get the other Snake and make your last wrap around the end bottle and make a double twist.
Bend the wire ends toward the mouth of the bottle to keep them out of your way.
The connections to the Snakes will allow you to angle your corners.
To complete your rectangle or square:
Take the loose end of one of the Snakes.
Loop and twist your wire over the bottom of the end bottle of the Snake, again using the lowest indentation a guide.
Put one of the loose bottles next to this one and twist the ends around the second bottle, continue with the third bottle and so on, until you reach your last bottle.
Make one more twist.
Get the other loose end Snake and make your last wrap around the end bottle and make a double twist.
Using your pliers, curl or bend the ends of the wire in a decorative way or you can just snip them off and bend them so they won't poke you.
Step 9: Making the Frame (Cutting the Wood)
Measure and mark your wood for cutting.
Cut two pieces the length of the Snake side.
For the other connecting sides, add 1-1/2 inches to your measured length and cut two pieces of this length.
I was very lucky. I had two 4 foot lengths and my measurements were 26 inches and 20-1/2 inches. Add 1-1/2 inches and it equaled 4 feet. I disregarded the waste area from the saw cut.
Yes, I am using pre-treated wood and am aware of the hazards. I will not be growing edibles in this box.
Step 10: Making the Frame (Prepping the Wood)
Center one piece of wood along the length of the matching side.
Use your pen or pencil to mark the approximate center of each bottle.
Do this for all four sides.
Drill pilot holes about 1 in from the edge on all four pieces of wood. If you want more stability, drill two holes for each mark. (you will need additional screws)
Pre-screw the screws into each pilot hole.
On the board that will overlap, drill two pilot holes at each end for the connecting screws.
Step 11: Making the Frame (attaching the Bottles - Snake Sides)
First, work on the Snake Sides (the sides that don't have the overlap).
Start in the center.
Match up the center screw against the side of your center bottle and hold it together with one hand. Make sure the bottom of the bottle does not extend below the wood edge.
Drill the screw all the way through the bottle.
Next do the ends. Screw the end screw into the end bottle. Make sure the bottle edge does not stick out past the end of the board. Do the same for the other end.
Now screw the rest of the bottles to the board, making sure the bottom of each bottle does not extend below the wood edge.
Repeat for the opposite side (the other Snake).
Step 12: Making the Frame (attaching the Bottles - Connecting Sides)
Beginning of Step 12:
Have the project flat on the ground, mouth of the bottle facing up.
Straighten out the connecting bottles that may have been flopping over.
Hold a connecting board against the floppy bottles on one side.
Screw the center screw into the center bottle like you did with the Snake Side.
Match up the wood against one side of your bottle length and hold it together with one hand. Make sure the bottom of the bottle does not extend below the wood edge.
Drill the screw all the way through the bottle. Do not attach the rest of the bottles to the board yet.
Turn the project so the Snake Sides are vertical to the ground. Match up the edges of the overlapping wood, keeping the joint flush and square. The bottles may not fit perfectly, but they are plastic and flexible, so force the corners flush. Hold the boards firmly together with one hand and, with the other hand, screw in the connecting screws.
Make the same flush connection on the other end.
Screw the end screw into the end bottle on one side. If you look into the bottle, there will be two screws in this bottle and they may cross. Do the same on the other side.
Then, screw the rest of the bottles to the board. It may be a tight fit, but force the bottles to touch the board.
Do the same thing on the on the other connecting side. Start from top: The Beginning of Step 12.
Your frame and bottles should be very sturdy.
Step 13: Finishing the Frame - the Final Check
Turn the box upside down to take a look at the squareness of the corners, make sure the contact is flush and to check out the bottle conditions.
One of the bottles skipped the drainage hole step so I had to heat up my soldering iron again.
Otherwise, it looked good.
Step 14: Make Your Interior Drainage Holes.
Heat up your soldering iron and start making interior drainage holes. These holes will allow the soil in the bottles to get water without having to water each bottle separately.
On the interior of the box, make about 6 to 8 holes below the shoulder of the bottle. Fit what you can on the corner bottles. They are kind of crammed in there and not as accessible.
Step 15: Adding the Bottom
Flip your work upside down.
Measure the area that you will need to cover. Or, place your work on your screen or hardware cloth and mark off the shape.
Cut your hardward cloth or screen to fit. If you are using screen, be a little generous on the sides. It gets warped so you may find yourself short.
Do the same for your landscape cloth but add about 2 inches all around.
Lay your landscape cloth over the bottom of your project.
Using your spatula or cardboard, tuck the edges in between the bottles and the frame.
Lay the hardware cloth over the landscape cloth and staple it to the wood frame (go by feel to make sure it fits).
I tucked the excess landscape cloth back over the hardware cloth so I would be less likely to be scratched by the sharp edges.
If you want, you can add strips of word or metal to cover the edges to make it more aesthetically pleasing, or add corner pieces to give it a little lift off the ground...
Make the loose ends of the copper wire into curly tendrils or if that is too cutesy for you, bend them around and down so the ends won't poke you.
Step 16: Adding the Soil & Planting.
Carry your box to where it belongs.
Put your potting soil in the box.
Fold a piece of paper into a cone, leaving a hole at the bottom big enough for the stones and soil to fall through but small enough to fit in the mouth of the bottle.
Put drainage stones in the bottles.
and start filling the bottles with the soil.
Plant and enjoy!