Decorative stone, rock and gravel have multiple uses in and around your home. Rock is a highly popular "hardscape" material and is used for such diverse purposes as mulch, ground cover, driveways and filler around pools and patios. Used as mulch, stone helps retain soil moisture, blocks weed growth and enhances drainage. Decorative stones for landscaping can also be used in gardens to create walkways or as a driveway material because it provides excellent erosion control. Inside your home, small pebbles can be placed over the soil of houseplants and are even used in craft projects. Before you buy landscape stone, consider the following questions:
• Are you looking for ground cover that will stay in place?
• What color rock would look nice near your house?
• How do you prep an area to put down decorative stone?
• How much rock will you need to cover your patio area?
• What type of rock is good for use in your driveway?
Types, Application and Calculation
There are many different types of rock and stone to choose from, depending upon your needs. Crushed stone, gravel and volcanic rock are available in a wide variety of colors, materials and textures. When applying stone as ground cover, you will need to prepare the area prior to laying it down to obtain the best results. By marking off the area you intend to cover, you can begin taking measurements that will help you calculate the amount of stone you will need. Large amounts of rock to be used in driveways or walkways are generally sold by the cubic foot or half foot. Smaller quantities for mulch or for indoor use are sold in bags ranging from 5 to 50 lbs.
Types: There are many different colors, shapes and textures of decorative stone available; and making a choice is mostly based upon personal preference. Most stones perform equally with slight variations. For example, smaller stones may tend to shift more in heavy rain. Rock used as mulch tends to retain heat, which can reflect back onto the plants and cause them to dry out. For patios, crushed rock works better than rounded river stones and will not move underfoot as much. Crushed, gray rock, or gravel, is sharp and irregular; it packs down well for driveways or for base rock under paths and walkways.
• Regional differences may affect the kinds of stone that are available for purchase
• River rock is rounded and smooth and works well for drainage
• For walkways or animal runs, choose rounded stone that is softer underfoot
• Volcanic rock is light, porous, packs down well and offers good drainage
• Do not use limestone gravel around rhododendrons or acid-loving plants because it changes the pH level
of the soil
Ground Cover Application: Adding stone for ground cover can be accomplished in several easy steps. First mark off the area you intend to fill, and then line with edging material to form a sharp border. Next remove all unwanted vegetation, yard debris and existing rocks. Rake the area until you have achieved a smooth, even surface. Spray the area with weed killer and put in a layer of landscape fabric to discourage weed growth. Fill in the area with 2" of paver stone base and smooth over; use a tamper to create a level surface. For wet areas, increase the layer of paver stone base to 6". Finally, top with decorative stone.
• Stone mulches are permanent; be sure you like the look before application
• Using landscape fabric helps decrease the movement of stones into the soil
• Black plastic does not work well as a liner because it blocks air and water from the soil
• Inorganic stone mulches do not harbor weed seeds like organic mulches
• Stone mulch does not attract termites like standard wood mulches
Calculation: The amount of stone needed depends upon your intended use. For small amounts of stone, such as soil cover for houseplants, container gardens, or craft projects, you can purchase small, 5 lb. bags. For larger jobs, you can buy 50 lb. bags or 1/2 to 1 cu. ft. of stone. For rock that will be underfoot, such as in a pathway or pool or patio area, it is best to use stone that is 1/4" to 3/4" in size. The amount of stone you buy depends upon the size of your project. Use the chart below to estimate the amount of stone needed for your project.
• Measure the square footage of the area you intend to cover with stone
• Multiply the square footage by the depth of stone you intend to use
• Example: an 8' x 8' area = 64 sq. ft. x 1/2' of rock = 32 cu. ft.
• The recommended depth for the stone used in driveways is 4" to 6"
• Stone is sold by the cubic yard -- an area 3' wide by 3' deep by 3' high
Stone Coverage Calculation
For 1 cubic yard of stone (27 cubic feet):
|160 sq. ft.||2"|
|108 sq. ft||3"|
|80 sq. ft.||4"|
|54 sq. ft.||6"|
Suggested Stone Depth
Size of Stone
|3/4" to 1"||3"|
|1" to 2"||4"|
Brick Chips: Brick chips are made from crushed, angular fragments of brick and are used as mulch or driveway stone. Brick chips are terra cotta color with deep reds and browns. Sizes range from to 3/4" to 1-1/4".
Crushed Gravel: Gravel is usually gray and is composed of sharp and irregularly shaped rock fragments. This makes it easy for the rocks to interlock and provide good packing. The size of gravel ranges from 1/4" to 3/4".Common uses include roads, driveways, base rock and pathways.
Lava Rock: Lava rock is porous, light and irregularly shaped; it is not available in all areas. This type of stone generally offers good drainage and packs down well. Additional layers must sometimes be added to maintain ground cover thickness. Lava rock is available in red or black hues and usually ranges in size from 3/4" to 1-1/4". You can use lava rock in driveways, gardens and along paths and walkways.
River Rock: River rock is round, smooth and easy on the feet since there are no sharp edges. Because of the shape, river rock tends not to pack down well, though it provides good drainage and is very attractive. Sizes range from 3/8" to 2-1/2". A smaller size of river rock is called pea gravel and is used in decorative concrete and other applications. The color of river rock includes shades of gray or brown. River rock is used in flower and garden beds and on walkways for erosion control.
White Marble Decorative Stone: Marble chips, made from fragments of marble, shimmer and sparkle and are used to cover soil in houseplants, container gardens, terrariums, fountains, and for craft projects. Do not use marble around plants that require high levels of acid as it will change the pH of the soil. Sizes range from 1/4" to 1/2", and stone is typically sold in 0.5 cu. ft. bags.