When summer’s flashy circus of wildflowers has passed and the last browned autumn leaf has fallen, an eye looking for signs of plant life is left with the conifers, those stalwart trees that stay green all year long.

Conifers do drop their needles and replace them with new ones—just not all at once. Their ability to photosynthesize all year long gives them a built-in advantage in living in places with a relatively short warm season. So does their natural chemical antifreeze, which prevents needles from freezing even in frigid conditions.