Every year, I-Plants magazine holds an award competition for plantscapes world-wide.  This year, Cityscapes won the Third Place Award for the exterior living walls installation at Boston’s Liberty Mutual Headquarters building on St. James Avenue in the Back Bay neighborhood.

The Story Behind The Installation

Liberty Mutual came to us unhappy with their current exterior living wall system.  The system was a cellular tray system mounted on four concrete pillars and planted with perennial plugs.  Constant watering would cause soil erosion and nearly all perennials would fail to come back in the springtime. The wall would need to be replanted entirely on an annual basis.  Also, Liberty Mutual did not like the ‘dead’ appearance of the perennials in the winter months.
A solution was needed to create a lush wall year-round that would have some color in the summer months.

The small cellular wall was swapped out with a tray system that would support 1 gallon annual, perennial and evergreen shrubs. This created a fuller looking wall just due to plant size alone.  The new trays were mounted on the existing mounts of the old system and used the same irrigation supply lines.  Zones were reorganized to properly water the new system.

Perennial plants supplement evergreen shrubs in the warm months, and then are replaced with evergreens before the frost.  A wall of 100% evergreen plants is more likely to overwinter with significantly less plant replacements needed in the spring, especially with an anti-desiccant application.
To improve the viability further, water can be left in the tray system for plant hydration during mid-winter thaws.  In the spring, only the plants that do not come back will be replaced with summer season perennials.  This creates a significantly more sustainable solution to the previous system while simultaneously improving the overall aesthetic of the site every day of the year.

When first planted, the walls have a shallow foliage depth and less noticeable textural differences.  But a matter of weeks into the growing season, the depth and textural changes of the plants is vast due to the size and layout of the plants themselves. The initial order of the planting gives way to the natural growth habits of the individual plants and creates an amazing organic pillar of greens that appears to have been there for years and years.

At the end of the season, fully grown perennials are removed and the wall returns to a state of similar sized evergreens and the cycle begins again in the spring.  The rotation of plants always feels in season and people who pass the wall every day experience the natural seasonal cycles of New England plant growth.

What Makes This Design Unique?

Liberty Mutual came to us unhappy with their current exterior living wall system.  The system was a cellular tray system mounted on four concrete pillars and planted with perennial plugs.  Constant watering would cause soil erosion and nearly all perennials would fail to come back in the springtime. The wall would need to be replanted entirely on an annual basis.  Also, Liberty Mutual did not like the ‘dead’ appearance of the perennials in the winter months.
A solution was needed to create a lush wall year-round that would have some color in the summer months.

The small cellular wall was swapped out with a tray system that would support 1 gallon annual, perennial and evergreen shrubs. This created a fuller looking wall just due to plant size alone.  The new trays were mounted on the existing mounts of the old system and used the same irrigation supply lines.  Zones were reorganized to properly water the new system.

Perennial plants supplement evergreen shrubs in the warm months, and then are replaced with evergreens before the frost.  A wall of 100% evergreen plants is more likely to overwinter with significantly less plant replacements needed in the spring, especially with an anti-desiccant application.
To improve the viability further, water can be left in the tray system for plant hydration during mid-winter thaws.  In the spring, only the plants that do not come back will be replaced with summer season perennials.  This creates a significantly more sustainable solution to the previous system while simultaneously improving the overall aesthetic of the site every day of the year.

When first planted, the walls have a shallow foliage depth and less noticeable textural differences.  But a matter of weeks into the growing season, the depth and textural changes of the plants is vast due to the size and layout of the plants themselves. The initial order of the planting gives way to the natural growth habits of the individual plants and creates an amazing organic pillar of greens that appears to have been there for years and years.

At the end of the season, fully grown perennials are removed and the wall returns to a state of similar sized evergreens and the cycle begins again in the spring.  The rotation of plants always feels in season and people who pass the wall every day experience the natural seasonal cycles of New England plant growth.