Dried herbs do make for surprisingly good foliage (smell nice, to boot
). As Hivefleet Oblivion says, smaller, thinner leaves (oregano, basil) work best, as they shrink down and break apart nicely while drying. Larger leaves (bay), twig-like leaves (rosemary), and traditionally ground herbs (sage) won't do you much good.
More traditional flock (not talking dyed sawdust, here, but the finely ground colored foam, as opposed to static grass) makes for nice, fluffy moss. Texture paste (
GW texture paint works, although generic ones from Liquitex, Vallejo, etc. can easily be colored for a cheaper bulk basing option) soil (dark, rich colors are most appropriate), patches of flock moss, and a scattering of herbs for fallen leaves would give a nice approximation of a healthy forest floor. Sculpting some roots or adding the odd shallowly protruding rock on larger bases would add a bit more character, when you have the space.
[edit:] Evertras: If you're asking about the resilience of the herbs when used as leaf scatter, it's pretty low. They're quite thin and crunchy, after all. That said, how frequently do you poke the tops of your bases? The glue used to attach them and the varnish that usually goes over the top helps, certainly, but their acceptable longevity is due more to their placement in a relatively protected area. Loading up on adhesive, as one might when making oregano vines (just a bead of PVA on a surface with the herb sprinkled on and smushed in) makes them more or less bulletproof, as the process becomes something like a cross between a mosaic and decoupage - the herb is completely locked into a matrix of glue or becomes a skin over, unable to chip off and break free, in either case.
