Plants for Retaining Walls

A retaining wall solves an engineering problem but creates a design one: bare concrete, timber or block walls dominate a garden until planting softens them. Whether you are dressing the top of a wall with cascading foliage, stabilising the slope above it or filling the narrow bed at its base, this collection covers the plants that make tiered landscapes look intentional.

Each planting position around a wall has its own physics. Along the top edge, the soil is the fastest draining spot in the entire garden, since water sheds down through the wall, so trailing and cascading species planted here need genuine drought tolerance once established. Spilling plants soften the wall face at roughly one plant per 60 to 80cm of wall length, and most will curtain down 30 to 50cm within two seasons. On the slope above, deep fibrous rooted tussocks and groundcovers do the structural work of binding soil against erosion, ideally planted in staggered rows about 50cm apart. At the base, the bed is often shaded and slightly damp from runoff, which suits lush fillers that would struggle up top. One caution: keep aggressive rooted trees several metres from any wall, as roots can shift footings over time.

For tall or multi tiered walls, plant the upper levels first and work down, so you are never hauling soil and stock over finished planting. Irrigation drippers on the top tier are a worthwhile investment, because hand watering the highest bed is the chore everyone abandons by February.

Contractors planting terraced subdivisions or large batters can order project volumes through bulk plants for landscapers, while home gardeners finishing the rest of a sloped block will find complementary choices across outdoor plants. Two of the hardest working species for wall tops and slopes are profiled in our grevillea care guide and dianella care guide, both proven soil binders in Australian conditions.