By Cynthia Bee, Conservation Garden Park
Many homeowners would be happy to reduce or eliminate lawn areas in their yards but don’t know what to use instead to fill the space. A dry river bed can be a lovely landscape feature that provides both a focal point and an organizing element for the landscape. Even better, once installed, it requires little to no maintenance.
If you’ve read many of our articles, you’re familiar with the “Localscapes” concept (and if you’re not, check out localscapes.com). A key feature of a Localscape is the “Central Open Shape” which may be lawn, groundcover or hardscape—or in this case, a dry river bed. That said, all dry river bed features are not created equal. Below are our best tips to ensure a quality result.
Depth: Make sure you dig down the area so it depresses like a river bed would. The depth is relative to the width. It should be about half as deep as it is wide. Make sure to dig a little deeper to account for the height of the rock that will line the bed.
Lining: Once it is dug down, line the area with weed barrier fabric. This is one of the few times we recommend using weed barrier fabric.
Large rock edge: At key places along the edge of your bed, and whenever it bends or turns a corner, add some larger rocks. When placing the larger rock, dig into the edge of the bed so 1/3 of the rock is burrowed into the ground. This will look more natural. Push the weed barrier fabric underneath the bigger rocks when you set them so they’ll help hold the fabric in place.
Rock Fill: The biggest mistake made on dry river beds is to order one size of rock, then fill the whole thing with that size. Mother Nature doesn’t work that way. Instead, get a mix of a couple of different rock sizes.
Budget-stretching: Order cheaper, smaller rock for the main fill for the bed then get some more colorful (and expensive) rock, and scatter it on top of the main gravel bed.
Peek-a-boo plants: If you look closely at the example photo, you’ll see some spiky foliage near the bridge against a rock cluster. this helps the bed look more natural. There is a drip line hidden in the rock to serve that plant.
Planted edge: Avoid creating a definite edge where river rock transforms to bark mulch. Although this example shows all-gravel surfacing, it’s okay to use bark mulch for adjacent beds so long as the transition is smooth. Soften the edge with plants that spill over into the river bed. Low-growing perennials will blur the edge, making it feel more natural.
Termination: The most awkward part of a dry river bed is figuring out how best to end it. If you have the space, widening it out into a pool at the end usually works best.
A dry river bed is just one of the many design elements that can help you create a landscape that is interesting and beautiful, while also reducing maintenance and water use. For more ideas, visit us at the Conservation Garden Park. http://conservationgardenpark.org