As it turned out, a large portion of the stuff was for Vietnam jungles that I have largely kept putting off for the last five years. Since I had the stuff out, I figured that I might as well finally make some of that jungle foliage, and maybe even reduce the supply heap a little further.
I scribed the plastic with an hobby knife into rough shapes, snapping off the unwanted bits, followed by filing/sanding the pointy spots into softer curves, and then beveled the edges with a rotary tool similar to a Dremel. The resulting bases looked more or less like the ones pictured below.
After pulling out a couple of 20mm Britannia Vietnam figs for scale, I further narrowed my selection of materials to that which would best work in 20mm. Some of the Palm trees and bushes that I had collected, had nubs on the bottom, so I drilled holes in some of the bases, and clipped the nubs to fit into the bases. I then used low temp hot-melt glue applied with a tiny glue gun to glue the trees, bushes, palms, ferns, and cycads in place. A few of the plants had hollow cores, so I glued styrene rod posts on the bases to receive those.
Once all of the plants were glued in place, the bases were ready for painting and flocking.
The plastic bases were painted with a mustardy yellow enamel, allowed to dry, and then flocked with my yellow/green "jungle" terrain mix, using artist's acrylic matte medium as the glue.
A variety of fern like plants were made using individual leaflets from full sized artificial ferns, to make the miniature fronds. Typical ferns would get 5-9 fronds glued into place to create the spray of the miniature fern. Other plants were made from clusters of leaves from various artificial plants. Some examples of palm trees and stands of jungle plants are shown below with a couple of figs added for scale.
Here are a few photos showing how the jungle looks in a game.
The new jungle bits will cover about five square feet on the table, and gives me about ten square feet of these types of plants total. I can mix them with other deciduous trees and lichen to cover a decent sized battlefield. In addition to being able to make Vietnam a little more lush, I managed to reduce my basement clutter by about two boxes of stuff, and found a few other things that had accidentally been hidden away in the boxes.