Garden Mastery Tips
Dry Stream Beds
A dry stream bed is a stone-lined channel or gully that mimics a natural watercourse. Stones and boulders are placed along a meandering course as if the force of water put them there. Dry stream beds, also called dry creek beds, usually include plants along the edges to enhance the natural look, and often incorporate stepping stones, bridges, or "waterfalls."
If you have an area of your landscape that's too soggy, dry, hot, or shady to grow plants, consider creating a dry stream bed. A dry stream bed can reduce topsoil erosion in areas in which runoff is a problem. It can reduce water use by replacing thirsty lawns and plants with rocks, while adding a natural-looking element to your landscape. Dry stream beds can also be used to correct a drainage problem or channel storm runoff from heavy rains or seasonal water runoff. (If water will flow through your dry stream bed at any time during the year, check with your local authorities and obtain any necessary permits before redirecting water to the public stormwater system.)
Before creating a dry stream bed, observe the positions of the rocks and the overall scale of natural creek beds. Notice how natural streams widen on the bends and how boulders that are too large for the current to move remain in the middle of the stream, while smaller ones are washed to the sides.
Your dry stream bed will look best if it follows an existing slope or change in elevation, even if it's not a natural feature of your landscape. If you have the space, try to disguise the "headwaters" of the dry stream bed by making it appear to come from behind a large boulder or group of plants.
When planning the course that the dry stream bed will follow, keep in mind that natural creek beds are usually wider than they are deep. A ratio of 2:1 should look about right. For example, if you want your dry stream bed to be about 4 feet wide, make it about 2 feet deep. Your dry stream bed should follow a meandering or curving path rather than a straight line. You may want to include a promontory or small beach to add further interest.
After you have defined the path of your dry stream bed, mark the edges with landscaper's paint. Remove any grass, weeds, or other vegetation. Dig the channel as deep as you like, maintaining about a 2:1 ratio as described above. Move the excavated soil to other parts of your landscape or mound it up along the sides of the channel to create banks, and tamp it down.
Line the channel with landscape fabric to prevent weeds from getting established, and pin it down with fabric pins or pieces of bent coat hangers. Cover the landscape fabric with a layer of sand or gravel, or spread river rocks down the length of the channel.
If the stream bed will be used to carry water, you will need to mortar all the rocks into place. Work in a small area at a time, as the mortar hardens quickly. Apply at least 2 inches of mortar, install the rocks, and work your way down the channel.
Choose rocks, stones, and gravel in a variety of shapes and sizes, combining smooth river rocks with sharper-edged rocks to make it look natural. Use rocks that are in scale with your setting and with each other-don't overwhelm a small stream bed with huge boulders.
Place small and medium-sized stones along the center of the channel; avoid organizing the rocks in any pattern. Add larger rocks or boulders both along the edges and in the middle of the stream, as if they are too heavy for the current to move. Put large boulders at the bends in the stream and to disguise the headwaters. For a more natural appearance, put some rocks on top of each other or partially bury them. Move the stones around to get the look you want, filling the spaces with more river rocks. Spread fine gravel at the lower end of the dry stream bed to create the appearance of naturally deposited sediment.
Add plants along the banks (cut an X in the landscape fabric and insert the plant into the soil beneath it). Use native plants wherever possible to add to the natural appearance and reduce maintenance. To further enhance your dry stream bed, add a piece of driftwood, a moss-covered log, stepping stones, or a stone slab for a "bridge."
Beaulieu, David. How To Build Dry Creek Beds for Landscape Drainage. Retrieved January 11, 2005 from http://landscaping.about.com/od/sitegradingdrainage/ht/dry_creek_beds.htm.
Creating a Dry Stream Bed. Gardening by the Yard: Episode GBY-509. Retrieved January 11, 2005 from http://www.hgtv.com/hgtv/gl_landscaping_design/article/0,1785,HGTV_3596_1378275,00.html.
Dry Creek Garden. Landscape Smart: Episode LDS-103. Retrieved January 11, 2005 from http://www.hgtv.com/hgtv/gl_design_other/article/0,1785,HGTV_3566_1370513,00.html.
Duchene-Carson, Penny. Incorporate a Dry Stream Bed into Your Landscape. Gardening in Larimer County. Colorado State University Cooperative Extension Master Gardener. Retrieved January 11, 2005 from http://www.colostate.edu/Depts/CoopExt/LARIMER/mg010630.htm.