yes.

You shoud avoid driving on your fake grass as well as natural grass. In the long run, it destroys them.

http://www.azluxurylawns.com/fake-grass-lawns

So long as there is soil under the fake grass, you could cut holes in the medium that supports the fake grass and plant your flowers.

Watering and fertilizing the flowers, may be problematic, however, since the fake grass may not be designed to be wet.

You could be most successful planting flowers in pots and then positioning the pots on the fake grass, arranging them anew after collecting them to water and fertilize.

inside, fake grass.

outside, real grass.

Many craft stores sell fake grass material. For fake grass to use in flower arrangements or decor, a local craft store would be the best place to go. If looking for AstroTurf like products, then try a home improvement store.