The appeal of trees with purple foliage lies in the striking contrast they introduce to a landscape dominated by green. This deep, rich coloration provides visual interest throughout the growing season, transforming an ordinary garden into something more dramatic. The vibrant hues are the result of specific natural compounds produced by the tree. Understanding the source of this color and the species that display it allows for intentional and effective landscape design.
The Pigments That Create Purple Foliage
The purple and deep red colors in foliage are primarily due to a group of water-soluble compounds called anthocyanins. These pigments are stored within the cell vacuoles of the leaves, where they absorb light in the blue-green spectrum. Trees with purple leaves produce high concentrations of anthocyanins, which effectively conceal the dominant green pigment, chlorophyll.
The production of this pigment is often a response to environmental stressors, such as intense sunlight or UV exposure. Anthocyanins function like an internal sunscreen, protecting the leaf’s photosynthetic machinery from damage by absorbing excess light energy.
Prominent Trees with Consistent Purple Leaves
Some trees are selectively bred or naturally inclined to maintain their purple coloration from spring through fall.
The ‘Crimson King’ Norway Maple (Acer platanoides ‘Crimson King’) is a large example, growing to approximately 40 feet. Its broad, deeply lobed leaves maintain a deep reddish-purple hue throughout the summer. It is valued for its tolerance to urban pollution and various soil conditions.
The Purpleleaf Plum (Prunus cerasifera ‘Thundercloud’) is a popular, smaller ornamental tree, typically reaching 15 to 25 feet tall and wide. It is often one of the first trees to bloom in spring, displaying fragrant pink or white blossoms before its rich, dark purple leaves fully emerge. This species is hardy across USDA Zones 4 through 9.
A classic choice for its massive size and dramatic color is the Copper Beech (Fagus sylvatica purpurea), a large shade tree that can reach heights over 60 feet. Its deep burgundy-purple foliage provides a dense, dark canopy throughout the warmer months. For smaller gardens, cultivars of the Japanese Maple (Acer palmatum), such as ‘Bloodgood,’ offer all-season purple foliage on a smaller scale, typically maturing between 15 and 25 feet.
Trees Where Purple Foliage is Seasonal or Partial
Not all trees that display purple leaves maintain the color consistently throughout the year or across their entire canopy.
The Smoke Tree (Cotinus coggygria ‘Royal Purple’) is a striking example, growing as a large shrub or small tree up to 15 feet. While often a deep purple, the color can sometimes appear as a smoky reddish-green, depending on the specific growing conditions.
The ‘Forest Pansy’ Redbud (Cercis canadensis ‘Forest Pansy’) features heart-shaped leaves where the purple is transient. New growth emerges brilliant purple in the spring but gradually matures to a darker, sometimes green-tinged hue as summer progresses.
Similarly, the Purple-leaf Sand Cherry (Prunus x cistena) produces a vibrant reddish-purple color that is most intense on new growth. This species requires full sunlight to avoid fading to green.
Some cultivars of Crape Myrtle (Lagerstroemia), such as ‘Purple Magic,’ feature dark purple leaves and grow into a small ornamental tree. The deepest purple is observed on the newest foliage as it emerges in the spring. Older leaves may lose some color intensity as temperatures rise, which is common in dark-leaved plants sensitive to heat and sun exposure.
Planting and Maintaining Purple-Leaved Trees
The successful cultivation of purple-leaved trees relies on providing conditions that encourage the maximum production of anthocyanins. The most significant factor influencing color intensity is sunlight exposure, since the pigment acts as a protective compound. To achieve the most vibrant purple, a tree should receive at least six hours of direct sun daily. Insufficient light will cause the leaves to revert to a greener color as chlorophyll production dominates.
These trees generally prefer well-drained soil. Many species, like the Purpleleaf Plum, appreciate deep watering, particularly as they establish their root systems. When planting, it is important to consider the mature size of the chosen species to ensure adequate space for its growth habit. Fertilizing annually in the spring with a balanced, slow-release product supports vigorous growth without diminishing the intensity of the leaf color.