A tiered garden is an attractive and functional way to manage a steep grade. On an ungraded hill garden, rainwater can wash soil downhill, eroding and damaging the garden and removing valuable topsoil. Tiers prevent rainwater from flowing quickly downhill, keeping the soil intact and allowing the plants to absorb the water.
Tiered gardens are often built on steep grades. Even with the tiered layout separated by retaining walls, erosion can be a problem. Decrease erosion by using a layer of mulch. Mulch will prevent rainwater from impacting the soil directly and knocking particles of dirt free in a process called splash erosion. For an attractive look, match your mulch to your garden retaining walls. For example, use bark mulch with wooden retaining walls and use gravel or crushed shells with stone retaining walls.
For a minimalist approach to tiered gardening, turn your outdoor stairway into a garden. Place fluted planters on one or both outside edges of the stairs to give the garden a stylish, ornamental look or use simpler planters for a more understated appeal. Alternately, place a row of low planters in the middle of the stairway, creating a divided staircase. For a more elaborate effect, combine a stairway garden with a classic tiered garden beside the stairs. Grow brightly colored flowers in the planters and place larger plants such as flowering shrubs, fruit trees and specimen trees in the tiered garden behind.
Tiered Garden Patio
Build a patio in the middle of your tiered garden. Grow smaller plants such as flowers and small bushes on the tier above the patio and larger plants such as trees below to create the impression of being surrounded by nature. If your garden is not too big to make if feasible, let the patio double as a gardening workspace. You can stand in the patio and tend to the small plants directly above you or water the trees directly below without having to haul your gear between tiers.