Climate warming is affecting the composition and distribution of Andean tropical montane forests (TMFs), leading to varied growth responses among tree species. However, the underlying mechanisms driving growth responses to climate warming remain largely unexplored. To investigate this, we established a common garden experiment along a 2000m natural thermosequence in the Andes. We planted individuals of 15 dominant Andean species from both montane and lowland origins under common soil and water conditions at different temperatures. We measured 19 leaf traits, including photosynthetic, thermotolerance, structural, and water use to explore their influence on tree growth responses to warming and cooling. Relationships between individual traits and growth showed the significant influence of thermal tolerance and the temperature response of photosynthesis in all but one treatment. When combining all traits, leaf nitrogen content emerged as the primary trait linked to growth in the trees home environments while leaf mass per area was the key trait influencing growth responses to temperature change. Overall, these traits explained over 50% of growth in three of four treatments and 25% in the remaining case. Climate change can alter trait growth relationships, however our understanding of trait influences on growth responses to warming remains incomplete.