The answer to 'why is my retaining wall invasive plants' is that invasive plants can often take root and grow along retaining walls. This is because retaining walls provide a stable, sheltered environment that can be ideal for the spread of certain aggressive plant species. The cracks and crevices in the wall structure can allow roots to take hold, while the wall itself can block sunlight and airflow that would normally limit the growth of these plants.
Some common invasive plants that may take over retaining walls include ivy, vines, weeds, and even small shrubs. These plants can damage the integrity of the wall over time, pushing through the mortar and causing cracks or destabilization. Addressing an invasive plant problem on a retaining wall often requires a combination of manual removal, herbicides, and ongoing maintenance to keep the plants from returning.