Hey Bruce:
There are several items you could use. Like slodder said, Woodland Scenics makes some nice static grass which comes in a variety of colors like several shades of green, burnt grass (kind of yellow/brown), autumn grass (yellowish in color), etc. A nice effect is to mix several shades so you don't have that too even look to it.
Heki also makes some nice static grass products, and one that I've used for longer grass comes from Noch and comes in a sheet. It looks like bristles that I think are clustered together using fine netting or something similar. It can be cut with a scissors to fit a desired area, or pulled with your fingers to thin it out.
All of these products are available from a Model Railroad Shop. I know we carry all of them at Walthers where I work.
http://www.walthers.comNo matter what you use, again like Slodder suggested, it's always a good idea to slightly tone down the colors either with pastels, or with some light drybrushing.
Good luck Bruce. Hope this helps.
John