I found these cute 'build it yourself Mechanical Garden' projects. 

Blooming Tropical Flower:
The basic sidewinder gear train controls a long arm that pushes a flexible wire through a plastic cup.  The flower blooms when the wire is pushed up and closes when the wire is pulled down.  The slip gear on the sidewinder gear controls keeps the gear train from breaking up when the lever arm reaches its stop points.

The flower is made from 5 Popsicle sticks hot glued to a small round piece of foam rubber.  The Popsicle sticks were decorated with foam rubber and toilet paper.  The stamen are pipe cleaners with a bead on the end.  The pistil is the round piece of foam rubber on which the Popsicle sticks are glued.

Swaying Grass:

A power top gear train pushes a beam with grass blades attached.  When the beam hits a touch sensor, the motor reverses and a rubber band pulls the beam back.  The control program repeats the sequence when the wind is blowing.

Dancing Flowers:
A Fwd-Rev-Rt-Lt Chassis, modified for the micro motors and MIT programmable Cricket, makes the rose turn and the daisy sway.  The program loops around a right turn and then a left turn.

Found at www.build-it-yourself.com/project-mechanical-garden/garden plants