“Water, water everywhere,
And all the boards did shrink;
Water, water everywhere,
Nor any drop to drink.”
You’ve probably read this verse from The Rime of the Ancient Mariner by Samuel Taylor Coleridge. It’s an apt description of the river rock mulch in my yard.
This year, I spent weeks digging rock out of the soil in my back yard so I can begin planting next year. I still have more to go. On top of that, I spent about 10 days last September expelling tons of rock mulch and landscaping fabric from my front yard.
There’s also a sea of rocks along the west side of my house and all the way to the back property line. It’s ugly. Am I going to remove that tonnage, as well? Not a chance. I may develop a small area for a vegetable garden, but the rest of the rock will stay. Life is too short.
If you, too, find yourself drowning in a sea of rocks, what can you do?
You can create a meadow of spreading ground covers and other perennials. Just move some of the rock out of the way, cut a hole in the landscape fabric, amend the soil with a little compost, and install seeds or baby plants.
If your area has a western or southern exposure with lots of sun, you can use plants such as these 11 lively lovelies:
- Prairie winecups (Callirhoe involucrata). This long-blooming ground cover, a Plant Select winner, sends out runners up to 30 inches long. Because it grows about five inches high, it’s tall enough to hide rocks. Plant this puppy, and it will reward you with stunning magenta blooms from early summer till frost. In the fall, prairie winecups will produce small wagon wheels of seeds. Spread the seeds around, and you’ll have lots of babies by the following spring.
- Soapwort (Saponaria ocymoides). When this evergreen ground cover is happy, it spreads far and wide. I have one exceptionally happy pink soapwort in my front yard that has grown into a plate that measures 40 inches wide and four inches high. After blooming in the spring, soapwort produces hundreds of seeds, which you can pull off and scatter to produce baby plants. Or you can simply wait for soapwort to self-sow and produce babies on its own for transplanting. Soapwort comes in both pink and white. I’ve found that the pink variety is more robust than the white.
- Candytuft (Iberis sempervirens). This tough, evergreen beauty erupts with masses of tiny white flowers in early to mid spring. It will spread 12 to 18 inches. If you sheer it after it blooms in the spring, it may rebloom in the fall.
- Rozanne cranesbill (Geranium ‘Gerwat’ Rozanne). Another long bloomer, Rozanne grows about 18 inches wide and 24 inches tall. This ground cover’s purple blooms are simply stunning. You may have to cut it back in late summer if it becomes leggy, but it will rebloom till frost.
- Sedums. Some of our beloved sedums, such as autumn joy, have been reclassified as the genus Hylotelephium for ease of pronunciation. Autumn joy (Hylotelephium ‘Herbstfreude’ Autumn Joy) produces pink blooms and grows 18 to 24 inches high. Low-growing Angelina sedum (Sedum rupestre ‘Angelina’) is one of my favorites, with its lime green summer color and orange/red fall/winter color. At three to six inches high, it’s tall enough to cover river rock.
- Orange carpet hummingbird (Zauscheria garrettii). If you like neon orange, you’ll love orange carpet hummingbird. The plant explodes with tubular flowers in July and keeps pumping out blooms till frost. It grows four to six inches tall and 15 to 18 inches wide. Hummingbirds went gaga over this ground cover in my yard last year.
- Ground cover roses. Some are hardier and more drought-tolerant than others. I’ve found that seafoam, a gorgeous white ground cover rose that grows about 30” tall, tolerates all kinds of abuse. One disadvantage is that white roses tend to turn brown in intense sun. So you might get away with a white rose in southern exposure, but I don’t recommend one in a western exposure unless it gets occasional shade, especially in the afternoon. Ralph’s creeper, on the other hand, produces vibrant red blooms throughout the summer. No brownout problems with this guy. I planted one in my west-facing tree lawn in Denver and rarely watered it, yet it bloomed like a banshee. If you have an area with lots of foot traffic nearby, ground cover roses will keep dogs from pooping in your yard.
- Irises. With their strong upright form, irises provide a welcome contrast when you surround them with low spreading ground covers. The same goes for snapdragons. I’ve seen irises grow in the most godawful conditions, so a rock bed isn’t likely to intimidate them.
- Snapdragons. These colorful biennials already populate my future rock-based meadow, thanks to the efforts of the previous homeowner. I just let their seeds drop in the fall and wait for new plants to emerge.
- Mojave sage (Salvia pachyphilla). One of my newest favorites, Mojave sage is sometimes described as having silvery green foliage. Maybe my soil is different, but the Mojave sage in my garden has wonderful silvery foliage that happens to be blue. Although the plant displays showy mauve brachts surrounding violet-blue flowers, I actually prefer the foliage to the flowers and regard my Mojave sages more as small shrubs than as perennials. They grow 18 to 24 inches high and 24 to 30 inches wide.
- Color Guard yucca. For drama and architectural form, it’s hard to beat evergreen Color Guard yucca. With its variegated, yellow-and-green leaves and masses of creamy white flowers on stalks, this plant is a showpiece. In Colorado, the plant grows in a clump two to four feet tall and two to three feet wide. However, its spikes can shoot up five feet or so. In late fall, the leaves take on a rosy hue.
There are, of course, many other worthy perennials, and even shrubs, that you can use to disguise a rocky area. If you see one that you like at the nursery next spring, give it a try, as long as the plant tag indicates that it’s full-sun and drought-tolerant. Because light-colored rock reflects sunlight, it creates a great deal of heat for plants, and dries out the soil. You can, of course, irrigate your rock bed, but where’s the fun in that?
Next month, I’ll tell you about perennials that you can use in shady rock beds.