Red-leaved trees capture attention, whether their fiery color signals the close of the growing season or provides year-round contrast in the landscape. Some trees transform from green to scarlet only in autumn, while others maintain a deep, reddish hue throughout the spring and summer months. Understanding the science behind this coloration and the specific species involved allows for a better appreciation of this natural phenomenon.
The Biological Mechanism of Red Color
The vibrant green color of leaves during the growing season comes from chlorophyll, the pigment that captures sunlight for photosynthesis. As day length shortens and temperatures drop in autumn, deciduous trees shut down food production and stop synthesizing new chlorophyll. When chlorophyll breaks down, it reveals other pigments that were present all along, primarily the yellow and orange carotenoids.
The red and purple colors are actively produced by the tree through pigments called anthocyanins. These water-soluble molecules are synthesized from sugars trapped in the leaf’s cells when the tree begins to seal off the leaf. The intensity of red coloration is enhanced by bright, sunny days that promote sugar production, followed by cool nights. This red pigment is thought to act as a sunscreen, protecting the leaf’s nutrient-resorption process as the tree withdraws resources before the leaf falls.
Deciduous Trees Displaying Brilliant Autumn Red
Many common deciduous trees are celebrated for their seasonal red display, which occurs after the first cool nights of autumn. The Red Maple (Acer rubrum) is widely recognized for its consistent and striking scarlet to crimson foliage. Sugar Maples (Acer saccharum), famous for syrup production, also feature intense autumn color, though their display typically includes a vivid mix of red, orange, and yellow.
Oaks also contribute to the red spectrum of fall. The Scarlet Oak (Quercus coccinea) turns a deep, rich scarlet, which can sometimes persist on the tree into winter. The Black Tupelo (Nyssa sylvatica), also called Black Gum, offers a striking, glossy red or purplish-red that stands out in the landscape.
The Sumac (Rhus species), often seen along roadsides, produces dense masses of crimson foliage and can grow in poor soil conditions. Flowering Dogwood (Cornus florida) adds to the seasonal red palette, with its leaves turning a deep reddish-purple, often accompanied by bright red berries. The Sweetgum tree (Liquidambar styraciflua) is valued for its distinctive star-shaped leaves that transition into shades of red, purple, and orange.
Trees with Permanent Red or Burgundy Foliage
Unlike seasonal performers, some trees possess a genetic trait causing them to produce anthocyanins throughout the growing season, resulting in permanent red or burgundy foliage. This coloration is present from spring emergence until the leaves drop in the fall. These trees are often cultivated as ornamental specimens to provide consistent color contrast against green landscapes.
Specific cultivars of Japanese Maples (Acer palmatum) are perhaps the most popular examples of this year-round red foliage. Varieties like ‘Bloodgood’ maintain a deep, reddish-purple or “blood-red” color throughout the spring and summer. This deep, dark pigmentation makes them highly sought after as focal points in gardens.
Another common example is the Purple Leaf Plum (Prunus cerasifera), which holds a dark, purplish-red leaf color during the warmer months. Certain cultivars of European Beech (Fagus sylvatica), such as ‘Purpurea Pendula,’ also feature leaves that emerge a purple-red and retain that color year-round, often forming a dense, weeping canopy. The persistent red color in these trees is not an indication of seasonal change but a stable, inherited characteristic of the cultivar.