Rising global temperatures are contributing to increased Urban heating affecting human well-being and ecosystems. Vegetation can help mitigate heat by providing shade and evaporative cooling. This study evaluates the cooling potential of two ornamental vines, Vitis × californica × vinifera ‘Rogers Red’ and Lonicera x heckrottii ‘Goldflame’ (goldflame honeysuckle), grown under different volumetric water content (VWC) regimes. The vines were grown on trellises in a greenhouse setting, with substrate VWC maintained at 0.15, 0.25, or 0.35 m³·m⁻³ for two months. A total of 12 vines per species were grown using an automated irrigation system. Canopy and background temperatures were measured using a FLIR thermal camera. Results showed that water stress impaired canopy growth in Rogers Red, whereas no significant effect was observed in the honeysuckle. In Rogers Red, lower VWC (0.15 m³·m⁻³) reduced leaf number, specific leaf area, and dry biomass, while honeysuckle exhibited consistent growth across all treatments. SPAD, NDVI, photosynthetic rate, and net assimilation rate did not differ significantly across treatments for either species. The higher cooling potential of Rogers Red compared to honeysuckle was attributed to its larger leaf size. Both vines demonstrated evaporative cooling potential, as indicated by lower canopy temperatures relative to the background temperature. However, Rogers Red exhibited significantly greater cooling potential at 0.35 m³·m⁻³ VWC, whereas honeysuckle maintained a similar cooling effect across all treatments due to its similar canopy area. These findings suggest that ornamental vines can provide cooling benefits however species selection can make a difference. Incorporating vine covers in urban areas can help in mitigating urban heat as cities continue to warm due to climate change.
