Evergreen trees, distinguished by their year-round foliage, offer consistent beauty and structure in any landscape. Understanding their mature height and growth habits is important for effective landscape design and long-term maintenance. Thoughtful planning ensures these long-lived plants thrive without creating future issues.
Factors Influencing Evergreen Tree Height
The ultimate height an evergreen tree achieves is primarily determined by its genetic makeup. Each species carries inherent programming that dictates its potential size and typical growth rate. This genetic blueprint sets the upper limits for how tall a tree can grow under optimal conditions.
Environmental factors significantly influence whether a tree reaches its genetic potential. Ample sunlight, consistent water availability, and nutrient-rich, well-draining soil contribute to robust growth. Climate also plays a role, as temperature zones and humidity levels affect a tree’s overall health and vigor. Trees growing in less than ideal conditions may not achieve the full height their genetics allow.
Proper care practices further support a tree’s development. Adequate watering, especially during dry periods, and appropriate fertilization provide the resources needed for healthy growth. Neglect or improper care can hinder a tree’s ability to reach its mature size, leading to stunted growth or poor form.
Understanding Evergreen Tree Growth Rates and Mature Heights
Evergreen trees exhibit a wide range of growth rates. Slow-growing evergreens typically add less than 1 foot per year, while medium-growing varieties gain 1 to 2 feet annually. Fast-growing evergreens can increase their height by more than 2 feet each year, with some vigorous species growing 3 to 5 feet annually. The time to reach mature height differs considerably among species.
Coniferous evergreens, known for their needles or scale-like leaves, include many popular landscape choices.
Coniferous Evergreens
Dwarf Alberta Spruce (Picea glauca ‘Conica’): A slow-growing conifer, reaching 8 to 13 feet tall, with an annual growth of 2 to 4 inches.
Colorado Blue Spruce (Picea pungens): A slow to moderate grower, gaining 1 to 2 feet per year, reaching 50 to 75 feet tall.
Eastern White Pine (Pinus strobus): A fast-growing species, adding 2 to 3 feet annually, commonly reaching 50 to 80 feet tall.
Leyland Cypress (Cupressus × leylandii): A very fast-growing conifer, often growing 2 to 4 feet per year, achieving 60 to 70 feet tall.
Green Giant Arborvitae (Thuja plicata ‘Green Giant’): A rapid grower at 3 to 5 feet per year, quickly reaching 30 to 60 feet tall.
Broadleaf evergreens, which retain their foliage in warmer climates, also vary in size. American Holly (Ilex opaca) grows at a slow to moderate pace, typically under a foot per year, reaching 40 to 60 feet tall. Southern Magnolia (Magnolia grandiflora) is a large broadleaf evergreen that grows 1 to 2 feet per year and can reach 60 to 80 feet tall.
Managing Evergreen Tree Height in Your Landscape
While genetically determined, the size of some evergreens can be influenced through specific pruning techniques. True height reduction is difficult for many conifers without harming the tree’s natural form or health. Pines and spruces, for instance, do not produce new growth from old wood, so cutting into leafless sections will not result in regrowth.
For pines, “candle pruning” involves pinching or cutting back the new, soft growth (candles) by one-half to two-thirds in late spring. This technique encourages denser growth and helps manage overall size without altering the tree’s inherent shape. Spruces can be pruned by cutting back new growth tips to a lateral bud, promoting a fuller appearance. Arborvitae, junipers, and yews are more forgiving and can be sheared or selectively pruned to maintain size, as they can produce new growth from latent buds on older wood.
Heavy topping, which involves cutting off the main leader or upper branches to drastically reduce height, is generally detrimental for most evergreens. This practice can lead to an unnatural appearance, weak new growth, and increased susceptibility to disease or pests. Choosing an evergreen species that naturally fits the available space at its mature height is a more sustainable approach than attempting to control an overly large tree through continuous pruning. Understanding the tree’s mature dimensions also helps prevent issues with proximity to power lines, structures, and other plants.
Choosing the Right Evergreen for Your Space
Selecting an evergreen tree involves careful consideration of your landscape’s present and future needs. Begin by assessing the available space, both vertically and horizontally, keeping in mind the tree’s mature dimensions rather than its size at planting. This includes considering overhead obstructions like power lines and the proximity to buildings or other plants.
Researching the mature height and spread of a chosen evergreen species is a foundational step. Reputable nurseries and gardening resources provide information on a tree’s typical growth rate and ultimate size, enabling informed decisions. Selecting a dwarf cultivar or a naturally smaller species can be a practical choice for limited spaces, reducing the need for extensive pruning later on.
Consider the tree’s purpose in your landscape, as height plays a significant role in its function. A tall, dense evergreen might serve as an effective privacy screen or windbreak, while a smaller, more ornamental variety could act as a focal point. Long-term planning, anticipating how the tree will integrate into the landscape over decades, helps ensure its continued success and beauty.