Why Governments Plant Flowering Shrubs in Highway Medians Rather Than Trees

Governments around the world often choose to plant flowering shrubs instead of trees in the median of highways. This decision is based on a careful consideration of various factors including maintenance and safety, root systems, aesthetics, space constraints, and ecosystem impacts. This article explores these reasons in detail and highlights the practical benefits of this choice.

Maintenance and Safety

One of the primary reasons behind the preference for flowering shrubs over trees is maintenance and safety. Flowering shrubs typically require less maintenance compared to trees, which may need regular pruning and can pose safety risks if they obstruct drivers' visibility. Flowering shrubs are often lower in height, making them less likely to obstruct or block drivers' views during critical moments.

Root Systems

The root systems of shrubs are generally less invasive than those of trees. This makes them a safer choice for areas where infrastructure such as pavements and drainage systems might be damaged by deep or widespread root growth. Trees, with their extensive root networks, can sometimes uplift paving, causing uneven surfaces or even hazards on highways.

Aesthetics

Aesthetics play a significant role in the decision-making process. Flowering shrubs can provide seasonal color and visual interest without the overwhelming height of trees. This contributes to an attractive landscape that enhances the driving experience. Shrubs also have a more compact shape, which allows them to fit better into the limited space of median areas, making them ideal for highways with strict landscaping requirements.

Space Constraints

Medians often have limited space due to design considerations. Shrubs, with their smaller footprint, can be more effectively used in these narrower areas. Trees, on the other hand, require more space for both their roots and canopy, which is not always available in median areas. This compact nature of shrubs makes them an ideal choice for highways, where space can be a limiting factor.

Ecosystem Considerations

Flowering shrubs can attract pollinators and support local wildlife. While trees offer extensive habitat for various species, the limited size of median areas may not accommodate the habitat requirements of larger trees. Flowering shrubs provide a more manageable and effective way to support local ecosystems without the need for large-scale habitat creation.

Cost

Flowering shrubs are generally less expensive to plant and maintain than trees, making them a more budget-friendly option for government landscaping projects. The cost savings come from lower initial planting costs, reduced maintenance requirements, and the lower water and irrigation needs for these plants.

Additionally, in many regions, the use of irrigation or sprinklers is minimized to reduce costs and maintenance. The low-maintenance and drought-tolerant nature of flowering shrubs makes them an ideal choice for areas where regular watering is not feasible or desirable.

While flowering shrubs offer numerous benefits, it is important to ensure that they are not over-plucked or damaged to preserve the visual appeal of the landscape. The landscaping efforts should be aimed at maintaining a visually pleasing environment for drivers without compromising the safety and functionality of the highway.

Lastly, it is crucial to consider the specific design requirements of highways. Trees are often seen as fixed objects, and their presence could pose greater risks in case of accidents. Shrubs, with their flexibility, can be more easily removed if necessary, making them a practical choice for the rapidly changing needs of highway infrastructure.