Temperate evergreen species may gain a physiological advantage through the ability of evergreen leaves to carry out photosynthesis for more than 1 growing season and during the winter season. I tested this hypothesis experimentally using Pinus strobus (Eastern White Pine) saplings, which produce needle-shaped leaves in late spring that typically last 3 growing seasons. Plants with leaves removed each winter (experimentally deciduous saplings) grew much slower after 1–2 years, and 100% died after 3 years, in contrast to only 5% of control plants dying. Plants with leaves lasting 2 years (shortened leaf lifespan) survived similarly to control plants and had intermediate growth rates. This experiment demonstrates that retention of evergreen leaves during the later years of their lifespan is critical to the survival and growth of evergreen Eastern White Pine saplings.