Lindenmayer System is a well-used algorithm which uses an iterative grammar set to simulate the growing status of plants. Although L-System is good at modeling the plant structure, it is inconvenient for describing and representing the changing shapes of plants during growing progress. For example, when a branch (or leaf) intersects with other organs or obstacle in the surrounding environment, there is no efficient mechanism to detect and avoid the collision. In order to solve the above-mentioned problem, we preprocess and build a hierarchical bounding volume structure for plants based on L-system. Our structure is then used to perform collision detections in each growing iteration of the L-grammar. By adopting this hierarchical structure, our system enables users to manipulate large-scale vegetation status in an efficient manner. Furthermore, our hierarchy data structures can be easily transformed into the format of Level of Detail, which is very useful for providing a multi-resolution landscape view for the users.