In my last blog, I covered slope stabilizing native plants used by Phipps Conservatory and Botanical Gardens in Pittsburgh, Pennsylvania. But there are other ways to tame a slope. Some gardeners in Pittsburgh have tapped in to a 2,000 year old idea: terracing. Of course, the most attractive way to deal with a slope happens to be the most expensive.
Although costly, terraces have their advantages!
- Reduced soil erosion
- Less runoff and more rain infiltration
- Level beds are easier to garden in
- Wider selection of plants
- Improved water retention
- Reduced nutrient leaching
- Simply lovely!
Depending on your hillside’s height, several terraces can be built with retaining walls of landscape timber, interlocking bricks or stones. Stairways built with similar material allow easy access to each terrace level. When building a terraced slope, you’ll need to cut into the hill, and level the terrace with soil manually (cut and fill) until you incorporate a level surface into the hillside. Terraces are definitely more work than planting a hillside, but look at the results!
The Davidson garden in Sewickley, a residential suburb of Pittsburgh, puts fun into terraces.
Fancy a floral Tyrannosaurus rex in your backyard? How about a putting green?
Underlying the sunny exuberance is some serious construction: well-built stone retaining walls and stone steps.
￼Terraces made this Toronto, Ontario, Canada garden more useable!
Terraces blends the house with the landscape in Dallas, Texas, USA. Terraces provide ample room for plantings as well several patios around the grand Hispanic-style house.
Terraces work best on a medium slope. On very steep slopes, retaining walls costs become prohibitive. Fortunately there is a solution. Building a deck is the simplest and least expensive way to create level space(s).
I didn’t see any decks over slopes in Pittsburgh. So, I dug through my photos to find some examples. After all, images are worth a thousand words! I found a deck built over a deep ravine site in Toronto.
Trees growing up to the deck height lessens the feeling of being perched high above the ground. Although some decks exploit the wonderful view! So don’t cover it with too much vegetation.
Terraces and decks not add level spaces for living and gardening, but they also add beauty. Planting a slope also has its charm as well as the added bonus of stabilizing the slopes. But how do we decide whether to build terraces or decks or just plant up the slope? In my next blog, Terrace or plant slopes? will answer that question.
Amy Rodriguez. SF Gate. How to Build a Terraced Slope in the Backyard
Building Products Corp’s YouTube video: How to build a terraced retaining wall
Houzz’s Sloped backyard: 111,612 photos
Pinterest’s Sloped backyard ideas
Pinterest’s Decks on slopes