Conifers, often recognized simply as “evergreens,” are a diverse group of cone-bearing plants that form the division Pinophyta. They are considered gymnosperms, meaning they produce “naked” seeds, usually housed within a cone. This category includes well-known species like pines, firs, spruces, and cedars, found across the globe. Although most conifer species are typically evergreen, retaining their needle or scale-like foliage year-round, the collective color palette is much more varied than just a uniform green.
The Standard Color Palette of Conifers
The typical color of a healthy conifer is indeed green, but this shade varies significantly between species. Many species, such as Douglas firs and certain hemlocks, display a deep, dark green that provides a consistent color in the landscape. This deep coloration is often associated with species that thrive in cooler climates.
Other conifers present distinct variations on the green theme, moving into the blue or silver range. The blue spruce (Picea pungens), for instance, develops a powdery, silvery-blue color due to a thick, waxy coating on its needles. Similarly, many junipers and some species of cedar exhibit a gray-green or blue-green color.
Brighter shades are also common, particularly in new growth or in certain cultivars. In the spring, the new growth, often called “candles” on pines, emerges as a lighter, yellow-green that contrasts sharply with the older, darker foliage. Some pines and false cypresses have been selectively bred to maintain a bright chartreuse or golden-yellow color throughout the year, especially when grown in full sun.
The foliage is generally classified as either needle-like (pines and spruces) or scale-like (arborvitae and cypresses). This structure affects how light is reflected, contributing to the perceived shade of green, blue, or yellow.
Why Conifer Colors Change Throughout the Year
Conifers are not immune to color changes, which occur for a variety of biological and environmental reasons. The most dramatic change is seen in deciduous conifers, a small group that includes larches and bald cypress. These species shed all their foliage annually, with their needles turning a brilliant gold or rusty orange in the autumn before dropping completely.
Many evergreen conifers also undergo a less dramatic, but noticeable, seasonal shift known as “bronzing” or “winter hardening.” Species like arborvitae (Thuja) and certain junipers develop a dull brown or purplish cast in response to cold temperatures and reduced sunlight. This color change is a protective mechanism, reducing water loss and shielding the photosynthetic pigments from intense winter sun.
Stress factors, such as drought, disease, or nutrient deficiencies, can also cause the foliage to change color outside of the normal cycle. A sudden yellowing or browning of the needles can signal an underlying problem. Furthermore, all evergreen conifers naturally shed their oldest needles, typically those closest to the trunk, after several years; these needles turn yellow or brown in the fall before dropping, which is a normal process.
The Biology Behind the Green
The primary reason conifers are green is the presence of chlorophyll, the pigment responsible for capturing light energy for photosynthesis. Chlorophyll molecules absorb light predominantly in the red and blue parts of the visible spectrum. Since the green light is absorbed poorly, it is instead reflected, which is what our eyes perceive as the color green.
This dominant green is often accompanied by other pigments, most notably carotenoids, which are always present in the needles. Carotenoids reflect colors in the yellow and orange range. During the growing season, the high concentration of chlorophyll masks the presence of these yellow pigments.
When a conifer experiences seasonal stress, such as cold temperatures or reduced light, the plant may break down some of its chlorophyll, revealing the underlying carotenoids. This biological process explains the shift to golden or yellow-green tones seen in winter bronzing or in the annual color display of deciduous conifers.