Novato Featured Garden: Redwood Retaining Wall
Details Landscape Art was called in during the spring of 2020 to renovate a hillside property in Novato, California. The project centered around replacing an aging retaining wall, replanting the hillside above it, and installing new irrigation and lawn areas below.
Redwood retaining wall
The existing retaining wall had been built approximately twenty-five years earlier and was badly deteriorated. The redwood was rotting, portions of the wall were failing, and it was clear that little allowance had been made for drainage behind the structure.
Existing rotting retaining wall
Water and wood do not mix. When soil and moisture remain in continuous contact with redwood, deterioration accelerates dramatically.
Retaining Wall Design Begins with Drainage
We agreed to construct a new redwood retaining wall of nearly the same dimensions as the original, but with several important improvements.
The new wall was built approximately twelve inches forward of the hillside to allow room for drainage behind the wall. We also maintained one to two inches of clearance between the wood and the soil to eliminate earth-to-wood contact.
Portion of new retaining wall mid-construction
Construction proved challenging because the wall incorporated several return angles that were not standard forty-five-degree corners. To add to the difficulty, temperatures frequently reached into the nineties and occasionally exceeded one hundred degrees during construction.
Once the wall was completed, we stapled plastic sheeting to the back side of the redwood and backfilled with three-quarter-inch crushed drain rock.
A three-inch perforated drainpipe wrapped in filter fabric was then installed along the entire length of the wall, gently sloping downhill to carry water away from the structure.
Proper drainage is one of the keys to a retaining wall that will stand the test of time.
Deer-Resistant Hillside Planting
Several months later we returned to relandscape the hillside above the wall, replace the lawn below, and install new irrigation systems.
Hillside landscaping and new lawn above and below new retaining wall
The homeowners loved gardening and were enthusiastic about colorful perennials and an English garden feel. Unfortunately, the property also experienced heavy deer traffic. Bucks, does, and fawns regularly wandered through the garden while we worked.
Working closely with the homeowners, we developed a list of colorful yet deer-resistant plants that would provide the desired appearance while surviving the local wildlife pressure.
Some requested plants, including roses and hydrangeas, had to be omitted because the deer would likely have consumed them immediately.
Following demolition of the old plantings, we discovered numerous gopher tunnels on the hillside. We recommended placing each new plant inside pre-made gopher baskets to protect the tender roots from damage.
Because portions of the slope were quite steep, jute netting was installed to control erosion while the new plantings became established.
With a truckload of new plants delivered to the site, we worked closely with the homeowners to position and space the plants according to their mature size.
Irrigation and Lawn Renovation
The existing lawn in front of the retaining wall was largely dead and in need of replacement.
A benderboard lawn edge was installed approximately twelve inches in front of the retaining wall, and a new lawn sprinkler system was designed so that irrigation water reached the turf but did not spray directly onto the redwood.
Protecting wood from unnecessary moisture is one of the secrets to long-lasting construction.
To complete the project, we installed a new Rain Dial irrigation controller to operate the lawn and drip irrigation systems efficiently.
This Novato featured garden demonstrates how thoughtful design, proper drainage, deer-resistant planting, and efficient irrigation can transform a difficult hillside property into a beautiful and durable landscape.