With the weather being what it is in Central Texas, the wise Austinite knows about the merit of crushed granite to lighten your watering load. Decomposed granite looks great and is easy to manage. This is probably why you see it everywhere.
Granite rock naturally breaks down into 1/4-inch or smaller particles called decomposed granite. Loose decomposed granite packs well and provides excellent drainage, making it an ideal mulching material for garden beds, but it is susceptible to erosion and must be maintained often. Stabilized decomposed granite has a stabilizer added to the granite and is used for high traffic areas such as patios, walkways and driveways. Decomposed granite with resin has a surface finish similar to asphalt that is durable and will not erode, so it is ideal for high traffic areas.
The process is really simple
Locate a suitable area to lay the decomposed granite, such as a walkway, patio, garden bed or driveway.
Drive wooden stakes in the ground at each corner of the area with a hammer. Tie string to each stake to lay out the borders if the area is squared. Paint lines on the ground with marking paint to lay out curved borders.
Cut the sod from the ground with a spade or sod cutter in the area where you are laying the granite. Dig up the grass roots to prevent future grass and weed growth.
Dig the excess soil out of the area to a depth of 8 to 12 inches to provide adequate room for the gravel base and decomposed granite layers. This is required for walkways, patios and driveways.
Install the area border with an edging material such as landscape timbers, brick or black plastic landscape edging. Borders prevent granite erosion from rain and winds and create a mowing edge to make lawn maintenance easier.
Place a layer of commercial grade weed blocking material over the soil in the excavated area. The material blocks sunlight and water from reaching the soil, which discourages grass and weed germination.
Spread a 4- to 6-inch gravel base in the area with a shovel for walkways, driveways and patios. Gravel provides a strong base to support the decomposed granite layer.
Fill the bordered area with a 4-inch layer of decomposed granite. Spread the granite over the area with a shovel or steel garden rake. Spread granite by hand or with a steel garden rake in small areas.
Compact the decomposed granite with a hand roller compactor or hand tamper. Add additional decomposed granite until there is a compacted layer that is 4 to 6 inches thick. This provides a strong surface area for walkways, patios and driveways and prevents decomposed granite erosion.
Spread a 2- to 4-inch layer of loose decomposed granite material as a mulch around plants. Leave a few inches around the plant stalk to allow room for growth. Mulching application does not require a gravel base and the installation of landscape edging is optional.
Things You Will Need
Weed blocking material
Steel garden rake
Decomposed granite works well as mulch because it provides minerals to plants. Although some replacement and maintenance is necessary as a result of loose decomposed granite erosion, it doesn’t break down as quickly as organic mulches, such as shredded bark mulch, which require frequent reapplication.