The Crape Myrtle (Lagerstroemia indica) is a popular ornamental choice in warmer climates, prized for its showy summer flowers and attractive peeling bark. While this species provides vibrant color, underestimating its mature size often leads to improper placement near homes and foundations. Planting a Crape Myrtle too close to a building results in maintenance difficulties and can compromise the plant’s long-term health. Successfully integrating this plant requires understanding its growth habit and ensuring adequate clearance for its eventual size.
Making an informed decision at the time of planting prevents future problems that require excessive pruning or costly removal.
Identifying Crape Myrtle Size Categories
The required planting distance depends entirely on the specific cultivar chosen, as Crape Myrtles vary widely in mature size. These plants are generally categorized into three main groups based on their potential mature height and corresponding canopy spread. The label on the plant tag is the most reliable guide for determining the appropriate planting location.
Dwarf Varieties
The smallest category includes Dwarf varieties, which typically mature to a height of six feet or less. These compact plants are often used in containers or as low foundation plantings, with many staying in the two to five-foot range. Examples include ‘Pocomoke’ and the ‘Dazzle’ series.
Semi-Dwarf Varieties
The Semi-Dwarf or Intermediate category reaches heights between six and fifteen feet. These are often grown as multi-stemmed shrubs or small trees and are suitable for smaller yards or near patios. Cultivars like ‘Tonto’ and ‘Acoma’ fall into this mid-sized range.
Standard Varieties
The largest category consists of Standard or Tree varieties, which can grow to twenty feet or more in height. Large cultivars such as ‘Natchez,’ ‘Muskogee,’ and ‘Sioux’ can easily reach thirty feet tall and twenty feet wide if left unpruned. Planting a standard variety in a small space often leads to excessive pruning or removal.
Calculating the Minimum Planting Distance
The fundamental rule for determining the planting distance is to account for the plant’s mature width or canopy spread, not just its height. Distance is measured horizontally from the center of the trunk to the nearest permanent structure, like a foundation wall or porch. The minimum distance required is generally half of the plant’s expected mature canopy width to prevent the tree from touching the structure.
The optimal distance is equivalent to the plant’s full mature spread, allowing the canopy to develop its natural shape without obstruction. Planting at this full distance ensures proper air circulation around the entire plant, which is beneficial for plant health.
Distance Guidelines by Size
Dwarf Varieties: With a mature spread of approximately three to six feet, the minimum planting distance is typically three feet from the house. The recommended optimal distance for these smaller shrubs is four to six feet to allow for full, natural development.
Semi-Dwarf Varieties: Spreads often range from eight to twelve feet. These should be planted at a minimum of six feet away from the foundation. Choosing a location that provides eight to ten feet of clearance offers a better long-term solution.
Standard Varieties: These varieties can spread up to twenty feet wide and require the greatest amount of space. They should be planted at least ten to twelve feet away from the house. A distance of fifteen feet or more is considered ideal for the largest varieties.
Structural and Maintenance Issues of Close Proximity
Planting a Crape Myrtle too close to a house creates a series of problems that extend beyond simple visual obstruction, affecting both the home and the plant itself. A common concern is root encroachment, though Crape Myrtle roots are characteristically fibrous and shallow. While they are unlikely to crack a solid foundation, planting them directly next to a sidewalk or driveway can lead to minor lifting or damage over many years due to the roots expanding just below the surface.
Canopy rubbing is a more immediate concern when the plant is sited too close to a structure. As the branches grow and sway in the wind, they repeatedly scrape against the siding, paint, and roofing materials. This constant friction can wear away protective coatings, leading to deterioration of the home’s exterior and potentially creating entry points for pests or moisture.
Maintenance and plant health are also negatively impacted by insufficient distance from a wall. When a canopy is pressed against a structure, it severely restricts airflow through the branches, which is necessary for the plant to dry out after rain or dew. This poor air circulation increases the plant’s susceptibility to fungal diseases, particularly powdery mildew and sooty mold, which thrive in humid, stagnant conditions.
Furthermore, necessary annual maintenance, such as shaping the plant or removing spent blooms to encourage reblooming, becomes nearly impossible in a cramped location. Finally, the plant’s characteristic summer blooms, while beautiful, eventually drop thousands of petals and seed pods onto the immediate surrounding area. This debris can quickly clog rain gutters and downspouts, or it can stain concrete and painted surfaces as the plant material breaks down and releases tannins.