Sure do. But it depends on what desert you are modeling. All deserts are not the same, in the US there are 5 major desert regions that are distinctly different from each other in geography and flora. Deserts are seldom without any plants, in fact, most abound in plant life. Depending on the region you model use the following:
Sagebrush and tumbleweed: dried lychen dyed or painted to green/brown for live plants and dull beige for dead.
Cactus: carved balsa for large cactii, painted watermellon seeds for smaller
Josua trees and other large bush/shrubs: use twisted wire, soldered and painted. wrap ends in tape to make a knob and dip the knob in fine ground foam appropriate to the season: eg: red for spring blossoms, green for early summer, brown for late summer/ winter
Other life forms: use individual strand wires in a bunch, paint brown, dip in glue and sprinkle with ground foam. makes a plant I think called an "occadillo" or something similar- grows around 15ft high.
Many other ideas, but it all depends as I said on the region of desert. Ground cover can be simple paint with sand sprinkle, or maybe you will need lots of rock molds. It all depends, but you get the idea.