Previous work in the animation of plant development and expansion has centered on the bottom-up approach, whereby models are specified in terms of developmental rules. These models are inherently difficult to use for goal oriented modeling as the final structure and development of these models are emergent properties. Top-down modeling has previously been introduced to remedy this problem by allowing interactive control of local characterists based on global positional information. We explore methods of extending top-down modeling to the field of animation. The ideas of keyframe animation are used in conjunction with L-systems to create goal oriented models of plant growth in preformed branching structures.