What Is Decomposed Granite
Decomposed granite is granite rock that has naturally broken down over millions of years into a mix of fine sand, silt, and small rock fragments. The particles range from powder fine to about 3/8 inch in diameter, creating a material with a natural, earthy appearance that compacts into a firm but permeable surface.
DG is one of the most versatile and affordable landscaping materials available. It costs significantly less than pavers or concrete, drains better than solid surfaces, and requires minimal maintenance once installed properly.
Types of Decomposed Granite
| Type | Description | Best Use | Cost per Ton |
|---|---|---|---|
| Natural (loose) DG | Loose granules, no binder | Garden paths, ground cover, mulch replacement | $25 to $50 |
| Stabilized DG | Mixed with a natural stabilizer for firmer surface | Walkways, patios, high traffic paths | $40 to $75 |
| DG with Resin | Coated with polymer resin for solid surface | Driveways, ADA accessible paths | $80 to $150 |
DG Colors and Appearance
Decomposed granite comes in a range of natural earth tones depending on the source quarry. The most common colors are gold, tan, brown, gray, and reddish brown. The color reflects the mineral composition of the original granite: iron rich granite produces red and brown tones, while quartz heavy granite produces lighter gold and tan colors.
Color does not affect performance. Choose based on the aesthetic you want with your home and landscape. Gold DG is the most popular for residential pathways. Gray DG complements modern or contemporary architecture. Reddish brown DG works well with Southwestern and desert style landscapes.
How to Install Decomposed Granite
Excavate the area to a depth of 4 to 6 inches. Install landscape fabric over the subgrade to prevent weed growth through the DG layer. Add a 2 inch base layer of compacted crushed rock (class 5 or road base) for drainage and stability. Spread DG in 2 inch lifts, wetting and compacting each lift with a plate compactor or hand tamper. Finish grade should be 2 to 3 inches of DG above the crushed rock base.
For pathways, install metal or steel edging along both sides to contain the DG. Without edging, loose DG migrates into adjacent garden beds and lawn areas within a few months.
Maintenance and Lifespan
Loose DG paths need occasional raking to smooth out displacement from foot traffic and rain erosion. Add a thin topping layer (0.5 to 1 inch) every 2 to 3 years to maintain depth. Weed seeds will blow onto the surface and germinate. Pull them while small or apply a pre-emergent herbicide in spring.
Stabilized DG lasts longer between refreshes (3 to 5 years) and resists displacement better. Resin bonded DG functions like a solid surface and lasts 8 to 12 years before needing a new top coat.
