This article is part of a set of two. The focus of this one is to give you an understanding of the wide array of gravel choices and the process involved in installing a new gravel bed. An article describing one possible cost-effective method to mulch Zone 0 with rock in the Berkeley Hills is found here.
Gravel as a Fire-Safe Landscape Material
Using gravel around a home and throughout a property is a fire-safe landscaping option. Gravel is available in a wide range of colors, including yellow, gold, red, blue, gray, salt-and-pepper, white, and black. This article includes photographs of a variety of gravel types along with price information from Acapulco Soil and Rock, one of the sources for gravel near Berkeley, giving readers a sense of material options and relative costs. Basic gravel installation considerations are also outlined below.
Local Gravel Resources
Besides big box stores, the two suppliers for gravel and stone near Berkeley are American Soil and Stone and Acapulco Soil and Rock.
Site Conditions and Preparation
When selecting gravel, it is important to consider terrain and intended use. On flat ground, installation often involves excavating 2–4 inches below the existing surface and installing a permeable weed cloth. Weed cloth allows for water infiltration while reducing weed growth. Edging can be installed to contain the gravel and maintain clean boundaries; common edging materials include brick, stones, and a plastic or metal edging material.
In this yard a plastic edging material was used to separate the gravel and the grass.
This project used stone to define the property boundary.
Depending on the depth of excavation, a base layer of less expensive gravel may be installed beneath decorative gravel, or be utilized as the most cost-effective option for a project. Using a base layer can reduce overall material costs while maintaining adequate depth and stability.
Depth and Use Considerations
For gravel beds located on flat ground with minimal foot traffic, a shallower gravel depth may be sufficient. However, if the gravel area will be used for walking, a minimum depth of 4 inches is recommended to ensure stability and durability. Paving stones can be added to a gravel base for easier egress.
This home entryway uses larger pavers with dark contrasting gravel between the stones.
This secondary pathway is defined by fewer pavers.
This pathway connects the driveway to the front entry staircase. Gravel is used around plant material.
Sloped Installations
When installing gravel on a slope, a maximum slope of 10 percent is generally recommended. Gravel size should include either ¾-inch aggregate, larger stones, or a mix with at least some ¾-inch aggregate; larger rock sizes are more resistant to movement during rainfall. For slopes steeper than 10 percent, building a small retaining area with larger rocks, or using a slope stabilization grid should be considered. These methods help hold gravel in place and reduce erosion.
Large stones are used to build a small retaining wall which holds gravel on the slope.
Decomposed Granite
In addition to gravel, decomposed granite (dg) is available through many gravel suppliers and can be installed in a similar way: start with a gravel base layer, spread the dg on top, compact the surface and seal the material in place. A DG Sealant stabilizes the material, keeps dust down and discourages weeds. Maintenance may be required every few years to refresh the surface. DG is available in blue and gold colors.
Blue decomposed granite defines the pathway. Metal edging material separates gravel from the path.
Materials, Quantities, and Delivery
Each photograph included below identifies the gravel type and provides current pricing. Delivery of larger quantities is available for a fee, from the supplier. Gravel is also available in bags, each bag contains approximately ¾ cubic foot of material. While other suppliers may offer a broader selection, Acapulco Soil and Rock maintains a well-organized display that was easy to view for this article.
To estimate the amount of gravel required for a project, use this gravel calculator tool.
Top left Salt & Pepper ¾” $141 cu yd, $13.50/bag; bottom left Salt & Pepper 3/8” same price; top rt. Desert Pink $178 cu yd, $ 10.15/bag; bottom rt. Slate Chips ¾” $128 cu yd, $9.60/bag.
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Top left California Gold 3/8” $127 cu yd, $11.40/bag; bottom left California Gold ¼” same price; top rt. Lodi Pebble 3/8” $133 cu yd, $12/bag; bottom rt. Yosemite Tan $142 cu yd, $12.25/bag.
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Top left Galaxy 3/8” $150 cu yd, $12.75/bag; bottom left Black Basalt Crush $118 cu yd, $10.65/bag; top rt. Red Lava 5/16” $86 cu yd, $9.25/bag; bottom rt. Red Lava Fines same price.
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Top left Yosemite Tan ¾” $126 cu yd, $12.75/ bag; bottom left California Gold ¾” $126.80 cu yd, $11.40/bag; top rt. Lodi Pebble 1.5” $160 cu yd, $13.50/bag; bottom rt. Lodi Pebble ¾” $145.50 cu yd. $12.90/bag.
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Top left White Dolomite 1.5” $345.60 cu yd, $20.50 per bag; bottom left White Dolomite 2/8”-5/8” same price; top rt. Red Lava 2” $86 cu yd, $9.25 per bag; bottom rt. Red Lava ¾” same price.
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Top left Pam Pebble ¾” $340/ton, $19/bag; bottom left Pam Pebble 1.5” same price; top rt. Mexican Mix ¼”-1/2” $600/ton, $27/bag; bottom rt. Mexican Mix 3/8”-5/8” same price.
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Top left Mexican Black 2”-3”; $600/ton, $27/bag; bottom left Mexican Black 1”-2” same price; top rt. Mexican Black Buttons 5/8”-7/8” $960/ton, $46/bag; bottom rt. Mexican Mix Buttons same price.
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Top left Mexican Red ½”-1” $740/ton, $29/bag; bottom left Mexican Sunburst ½”-1” $700/ton, $29/bag; top rt. Mexican Sunburst 2”-3” same price; bottom rt. Mexican Sunburst 1”-2” same price.
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Top left no gravel; bottom left Coral Sea ¼” $560/ton, $25/bag; top rt. MSI Black Polished ¼”-3/4” $35/50 lb. bag; bottom rt. MSI Black Polished ¼”-1/2” same price.
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Top left MSI Himalayan White Pebbles $30/50 lb.; bag bottom left MSI Himalayan White Pebbles ¼”-3/4” same price; top rt. Polished Black Pebbles 1”-2” $50/50 lb. bag; bottom rt. Polished Black Pebbles 1/2”-1” same price.
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Take a Walk
A walk around the neighborhood will provide more ideas for how gravel can be used in the landscape.
Below, photographs from Acapulco Rock and Soil show larger areas of gravel used in the landscape which provide a better idea of what different materials look like in greater quantity.
