How to Lay a Gravel Bed
If you live in an area that experiences drought, or you just don't have much time for watering a garden, then a gravel bed filled with plants that thrive in warm, dry conditions provides a gardening solution. Gravel helps control weeds and is available in a range of sizes and colors. So you can select the kind that will look best in your garden. For extra weed control, spread landscape fabric and place the gravel on top of it.
Screened gravel made from local stones provides a weed-free, natural look in a gravel garden bed. Local gravel is the most likely type to look in place in the landscape, but soft-colored gravel, such as red- and gold-tinted varieties, also can look natural. Select gravel in a color that complements your garden style or your house's bricks or other building materials, or choose a contrasting color for a bold look.
Non-screened gravel contains small particles and dust that trap water and encourage weed seeds to sprout, but screened gravel contains only gravel pieces of similar sizes, such as 1/4 to 1/2 inch in diameter.
Rock suppliers usually deliver gravel in square feet or square yards to homes, depending on how much the homeowners need.
Designing the Bed
Designing your gravel garden bed on graph paper and selecting plants for it that thrive in your area's conditions will help prevent costly and time-consuming mistakes. When you sketch your gravel garden on graph paper, make 1 foot of the garden bed equal to 1 square on the graph paper, or use an alternative ratio, to keep the drawing to scale.
Select drought-tolerant flowering plants and/or other kinds of plants that grow best in the gravel garden location's available light. Plants available for sale include tags or labels that indicate the amount of sunlight they need to grow well. Full-sun plants need at least six hours of direct sun exposure every day, and plants for partially shaded gardens require four to six hours of direct sunlight daily.
Plant tags and labels also include their plant's sizes at maturity. Tall plants should be placed at the back of a gravel bed that borders a house, fence or other structure while tall plants should be in the center of an island bed, which is surrounded by lawn. Low-growing plants should grow at the bed's front, and medium-size plants should be between tall and low-growing plants.
When drawing your garden on graph paper, sketch circles that match the expected mature widths of your selected plants. For a natural look, group plants of the same type in threes, fives or other odd numbers.
Coastal, desert, Mediterranean and other drought-tolerant plants grow well in a gravel garden. They include:
- Sea thrift (Armeria maritima), which grows 6 to 12 inches tall and wide, and features globe-shaped clusters of small pink or white blooms in mid-spring. Sea thrift grows as a perennial plant in U.S. Department of Agriculture plant hardiness zones 4 through 8 and needs full-sun exposure.
- Adam's needle (Yucca filamentosa) is an evergreen shrub that grows 4 to 8 feet tall and 2 to 3 feet wide. Its stalk carrying creamy-white, bell-shaped flowers appears in late spring and rises up to 12 feet tall. Adam's needle is perennial in USDA zones 5 through 10 and requires a full-sun spot.
Adam's needle bears sharp spines on the ends of its leaves.
- Silver sage (Salvia argentea), which is perennial in USDA zones 5 through 8, offers feltlike, wrinkled, woolly leaves that emerge silver-white in spring and mature to silver- or greenish-gray in summer. In early summer, its spikes of pink-tinged, white, hooded blooms appear. Silver sage grows 1 to 3 feet tall and 1 to 1 1/2 feet wide. It is a full-sun plant.
Creating the Bed
Amending the soil with sphagnum peat moss before laying gravel helps provide the freely draining, moisture-retentive conditions in which most plants thrive.
Sandy and other freely draining soils don't need any amendment other than sphagnum peat moss to be suitable for a gravel garden. Soils that are clay or average loam benefit from having a 2-inch layer of gravel mixed into them to a depth of 8 inches after the sphagnum peat moss has been added.
Remove rocks and weeds, including the weeds' roots, from the soil by using a garden fork. Spread a 3-inch layer of sphagnum peat moss on the soil surface. Mix the sphagnum peat moss into the soil to a depth of 8 inches.
Rake the soil surface until it is flat and even. Spread landscape fabric on the level surface.
Place drought-tolerant plants -- still in their nursery pots -- on the landscape fabric, setting them in the locations where you will plant them. Check your design, and rearrange the potted plants until you're happy with the look of the bed.
Cut an X-shaped hole in the landscape fabric at each place you will plant. Use scissors or a sharp knife to cut the fabric. Fold back the flaps of fabric at each X-shaped hole, and dig planting holes with a trowel. Make each hole 1 1/2 times as wide as the root ball of the plant designated for that hole, and make each hole deep enough so that its plant will grow at the same soil depth at which it grew in its nursery pot.
Plant the plants at their original growing depths in the holes. Fill the gaps around the root balls with the soil you removed when digging the holes. Make the soil level with the soil covered by landscape fabric. Unfold the flaps of landscape fabric at each X shape, closing the X shapes.
Spread a 1- to 2-inch layer of gravel over the landscape fabric and under the plants' branches. Don't place gravel against the plants' central stems, or trunks.
Water the gravel garden bed, applying enough water to moisten the soil to the depth of the plants' root balls. Keep the soil moist, but not soggy, for about two weeks after planting, until the plants become established. Then water as needed to prevent the soil from drying out or to keep it moist, depending on your selected plants' requirements.
- Assorted gravel types and colors
- Black polythene or mulching sheet
- Assorted plants