Are polyethylene outdoor tree boxes suitable for use in heavy metal-contaminated soils?

Polyethylene outdoor tree boxes are increasingly popular in urban landscaping due to their durability and cost-effectiveness. However, their suitability for heavy metal-contaminated soils remains a topic of debate.

Polyethylene is chemically resistant and does not degrade easily, making it a potential barrier against soil contaminants. In heavy metal-contaminated areas, these boxes may prevent root exposure to toxic elements, protecting tree health. However, long-term performance depends on factors like soil pH, moisture, and metal concentration.

Studies suggest that high-density polyethylene (HDPE) resists corrosion from metals like lead or cadmium, but prolonged exposure to acidic conditions could weaken the material. Proper drainage and liner systems can enhance effectiveness.

While not a complete solution, polyethylene tree boxes offer a practical option for urban greening in contaminated sites, provided they are monitored and maintained regularly.