Traditionally we have used one symbol for trees, and another symbol for shrubs, with the only variance being the size of the symbol depending on what plant it's representing. We are interested in diversifying our planting plans by incorporating the simpler LandFX symbols, but is there a way to limit the possible choices when assigning a recently added plant a symbol?
Would it make sense to create another folder within blocks>graphics>planting>trees/shrubs with copies of our approved symbols (.dwg, .sld, .xml)? If this is the suggested method, how can I ensure that only these .sld files are visible when someone in the firm is adding a new plant to their project?

Thanks in advance,
-Cam