Questions about planter's pouches came up recently in a forum I frequent. I thought I'd post how mine are made. This is a design I have seen in the wild, and adapted for my own use.
First, the one-quart Ziploc. I have cut a piece of cardboard and inserted it into the Ziploc to make it easier to work with. I am working on a large plastic cutting board.
The side with writing is the front. If your baggie has no writing, note that one edge above the zip is shorter than the other. The long edge is the front. We'll begin applying tape on the back, just below the blue line.
Apply tape all the way down, overlapping each strip by about 1/3. Let the tape go beyond the sides, and go about 1/2-inch beyond the bottom of the baggie.
Clean up the edges, leaving enough to fold over to the other side. Turn it over.
Cut from the bottom of the baggie to the bottom of the tape on both sides.
Fold up the center, and remove the extra tape.
Fold in the sides.
Tape the front of the baggie. Go right past the top, adding 3-4 inches.
Clean up the edges, leaving enough room to fold, and turn everything over.
Again, cut from the bottom edge of the bag to the bottom of the tape on both sides, and fold the bottom up. Get rid of the extra tape at the bottom, but don't fold the sides yet.
Cut from the blue line at the top to the edge of the tape on both sides. Fold in the sides.
Beginning at the top edge of the baggie, apply tape to the other side of the top flap. Overlap a little at the top.
Lining up so the edge is flush with the rest of the pouch, clean up the edges of the top flap.
Get rid of those tiny sticky bits.
Fold over that top edge.
Remove the cardboard. Fold the top flap, then fold the pouch again. Crease it a bit on this second fold.
Apply velcro tabs to both sets of folds. As you can see, I put down one part of the tab, then dab it with a little chalk ink and fold the pouch to see where the other half of the tab goes.
Ready for letterboxy goodness! When you fill the pouch, the contents must fit in the bottom half, or the pouch will not fold properly.
Ready to plant (indeed, this one was planted an hour later).