Using gravel can also turn problem spots caused by shallow ditches, bare spots, and high traffic areas into workable parts of the landscape. Once established, these are easy care gardens that require minimum labor while still providing a palette for a variety of flowers, shrubs and grasses. The beauty of today’s gravel garden is that it can be grown anywhere as long as a few basic foundation principles are put into place.
What Makes Up a Gravel Garden?
Gravel gardens are created with natural and manufactured materials and built from the bottom up in layers. A large gravel garden is usually located in a wide, flat, sunny area. However, different sizes and grades of rock can improve the appearance and use of areas difficult to mow or maintain.
A Soil Foundation
Most plants require some type of growing medium to establish root systems. Gravel gardens start with soil as a foundation layer, prepared to receive all the materials that will be placed on top. Building a gravel garden is much the same as building a raised bed garden. In the end, the types of plants that will thrive are dependent on the underlying soil which is enriched with compost and other materials to create a fertile base.
Gravel and Hardscape
Gravel makes up the second layer and serves as background for plants and other features. It replaces lawn grass and the top 4 to 8 inches of soil, becoming the garden “bed.” Most gardens use rocks about 1/2 to 3/4 inches in diameter. Round, white pebbles are popular, but decorative gravel is widely available in other colors and shapes. Hardscape materials like stone, wood or metal edging are design elements added to keep the gravel in place. A building foundation, retaining wall, or fencing can work as a border for the gravel garden area. Large boulders, benches, trellising, birdbaths, and even water features add dimension and planting options. Choosing hardscape materials is where the creative process begins, limited only by the gardener’s imagination.
How Do Plants Grow in Gravel Gardens?
The final layer in this garden art project is plants. The root systems of selected bulbs, flowers, grasses and shrubs reach down through the gravel layer to access the soil at the bottom. Plants native to the area, which are drought resistant and adapted to the environment, make up a significant part of the flora. Other basic principles of gardening are applied with plants placed according to their specific need for light, shade, and water. An added benefit of a gravel garden is excellent drainage which almost all plants require.
Good Plants for a Gravel Garden
Listed below are plant genuses that are native to or will thrive across a number of USDA growing zones.
Bulbs
AlliumColchicumCrinum x powelliiNerine bowdenii
Shrubs
Ceanothus: New Jersey teaCistus: Rock RoseCytisus: BroomHypericum: St. John’s WortJuniperus: JuniperLavendula: LavenderRosmarinum: RosemaryThymus: ThymeYucca: Yucca
Perennials
Achillea: YarrowBergenia: SaxifrageCrepis incana: Pink dandelionEchinops: ConeflowerEryngium: Sea hollyEuphorbia: Red hot pokerNepeta: CatnipOenothera: Evening primroseOsteospermum: African daisyPapaver: PoppyPhlomis: Jerusalem sageSedum: SedumVerbascum: Mullein
Grasses
MiscanthusPennisetum: Fountain grassStipa
Bedding Plants
CosmosGanzaniaPortulaca: Moss rose
Climbers/Vines
Campsis: Trumpet vineTrachelospermum: Star jasmine
Why Choose a Gravel Garden
Almost all of the work surrounding a gravel garden takes place in the first two years. To become well established, these gardens initially require watering, every day and then once a week for a year or two after the plants have rooted into the soil.
Low maintenance
Once a gravel garden is established, the need to mow grass, pull weeds, edge, fertilize and water is either eliminated or greatly reduced. Most plant varieties are able to thrive on annual rainfall and gravel helps prevent weed seeds from sprouting. Fertilizer is usually ineffective and not recommended. An annual fall or spring cleanup of deadwood and spent plant material along with occasional light pruning are often all that’s needed.
Sustainability
All of these easy care elements add up to a sustainable garden that will return year after year without the constant work required to keep up with a lawn and soil based planting beds. Gravel gardens are often used in commercial landscaping and urban areas like traffic islands and parking lots.
Biodiversity
Many of the plants used in gravel gardens are native species that attract pollinators including native bees, butterflies and birds. These pollinators spread seed and pollen which encourages the proliferation of native flora and enhances the variety of life in the garden’s greater ecosystem.
