Parking lot designs depict large trees planted with the expectation that they will provide the ecological services of stormwater capture, cooling the air and shading. Yet, the harsh growing conditions in parking lots, including soil compaction, limited water access and high heat, limit the growth of the trees. How do these harsh conditions effect tree ecological function? Do shrubs, which are less costly and easier to replace, provide ecological function and are they limited by parking lot conditions as well? This study assessed tree and shrub transpiration over the course of growing season to understand plant water relations. Of the three tree species, transpiration at the leaf scale was not correlated to location in parking lot versus park setting, but trees were significantly smaller and less healthy in parking lot settings, which reduced canopy scale transpiration. Conversely, three out of four shrubs were affected by the location in parking lot versus the park setting, but size and health were similar. A parking lot design was made that showcases planting typologies iii appropriate to the amount of water infiltrating to the soil. Incorporating stormwater management, this design demonstrates the necessary infrastructure changes needed for full growth of trees which maximizes ecological services in a relatively small footprint.