It has been two years since I started the terraces on my nine foot high hillside in the backyard and this year they will be finished! The hillside extends 100 feet across the backyard; has a vertical height of nine feet; slopes at about 45 degrees giving an upward slope length of about 13 feet or so. We had to dig into the hillside to extend our lower backyard so we could build a pergola, storage shed, and firepit on the lower level.
Several methods were used to contain the inevitable erosion but none worked until I started the terrace concept. In those two years, I have added two pallets of red concrete landscape block and about ten tons of rounded river rock of all sizes. The two corners have to be finished – one around the pergola and hot tub and one around the storage shed. The base of the hillside is reinforced with a 30 inch height of railroad ties faced with a tight lattice. This project will be the left or east end which wraps around the pergola. Just describing the work already accomplished makes me tired!
I am estimating about 40 concrete block will be used in building the rounded terraces and I will build three levels each about three block high. They will be backfilled with garden soil and with their sunny location will become an excellent planting area. I have a number of plants ready to populate the backfill including pink and white peonies, purple coneflowers, mixed dahlia, and other pollinator varieties.
The clay bank presents digging issues but recent rains have softened the native soil. Rocks imbedded in the clay also present excavation issues and occasionally I uncover a pretty native rock which is added to the new rocky hillside.