How would I make marsh-type grass, like the long grasses of the Everglades? I don't think the hair/grass tip would help me, 'cause I don't think I could get it long enough with that while still remaining vertical. Maybe gumpaste cut into thin strips? I haven't worked with GP very much, so I don't know how stable that would be, or if I could even get it to stand up ~ even if I used an inch of BC to stick it into. Any ideas?
that looks like the tip that you use to make those little white flowers on the lily of the valley with tip #81.
What alanahodgson said looks like it'd work great!!! But if you don't have a cake side to do your grass against...
I think your best bet would be to make thin strips of gumpaste. If you let them dry for a few days before putting them on the cake, they will not droop. I would probably use royal icing to attach them to the cake..if your cake is covered in fondant. If your cake is covered in buttercream, I would just stick the grass down into the cake about 1/4-1/2". This would work just dandy!!!
I did the grass on this cake out of gumpaste. You do need to let them dry for several days so they're rigid. Make extra because they seem to break easily (at least mine did!). I made the crease in the middle with the back side of a knife. Hope that's helpful.