Updated: Nov 22, 2021
Roses are available in countless shapes, forms, scented or unscented, simple or complex, even for their drought tolerance. There are roses that climb and others grafted to become miniature trees called standards. Miniature shrub forms also exist (often found in florist shops), and of course the ever popular hybrid teas are just a few general types. Scanning The New Sunset Western Garden Book (2012), readers will see considerably more distinctive types, such as old versus modern varieties, "shrub" roses (even though they are all shrubs, this refers to how they behave and flower, which is less formal than hybrid teas), trademarked (an example will be discussed below), Damask, Gallica, Moss, China, even Bourbon roses. All have been hybridized and created for their unique character, but there are even more that are still grown as known species: R. banksaiae, R. foetida, R. glauca, and our own R. californica, are examples. This profile only scratches the tip of a longer list, highlighting that no two roses are alike, so why wouldn't there be forms that are grown as ground covers?
Ground cover forms are named cultivars but several are registered trademark plants. A bit of a rabbit hole to research, here are a few examples. One of my favorites that I used in my landscape designs was Rosa 'Popcorn', a miniature rose that did well in gardens, and in mass, had an appearance of fluffy popcorn adrift. In mass, they could be used as a ground cover, but to achieve this mass meant planting only about two feet apart...that can be a lot of plants depending upon the amount of space to cover. To improve on an idea, famed Weeks Wholesale Rose Grower, Inc. took this parent plant and created Rosa 'PP # 6,809,' better known as Rosa Shrublet™ Gourmet Popcorn (photo above). This new version has a little larger leaf and flower if not a greater size than its parent plant. To confuse buyers further, we also have Rosa x 'Novarospop' PP #24,773, or Rosa 'Popcorn Drift.' To my untrained eye, it doesn't look to much different the all the others, which for a designer is a good thing. What can be cringe-worthy is the call from the landscape contractors saying they cannot find the specified plant. In this case, I would substitute any one of these and adjust spacing as necessary. Anyway, plants labeled with drift® are another ground cover or small shrub rose produced by Star® Roses and Plants.
To really achieve ground cover status, we need to look not just at shorter heights but at roses that spread wider than tall. Enter Flower Carpet® roses, produced by Anthony Tesselaar Plants, providing a full range of colors including white. These shrubs can reach three feet in diameter and are known for the disease resistance. There is another, however, that can reach up to six feet across while maintaining a two foot height, Meidiland® roses, created by the French brand, Meilland. Their spreading capacity means using less quantity for ground cover applications, since spacing can be much further apart. They also share a resistance to diseases similar to the brands listed above. I have not seen them lately, but Meidiland® roses have also been grafted onto stalk to produce a tree-like form (shown here), essentially cascading like a weeping cherry. They need support, but if they can be found, offer a unique opportunity for a striking focal point in the garden.
There are still others to consider, such as Rosa rugosa (shown here) and Rosa californica that can spread but are often too tall to be really considered as a ground cover. Bramble might be more appropriate, still capable of spreading in a wide area. I discovered a mysterious ground cover rose at a rural cemetery along the coast (photo below). Walking through the cemetery, it took a while for me to notice the subtle green leaves spreading out on thorny limbs hugged close to the ground...everywhere...creepy, especially after it attacked my ankles. I am unclear if this plant is a specific species that has gone wild, or if it may have been an old rose that has adapted to mowing practices. I suspect it is actually a climbing rose with nothing to climb, given the long, stringy canes. Not in bloom at the time of my visit, I am compelled to return in spring to see if it blooms. There are people that wander through cemeteries and abandoned farmhouses looking for older species, so maybe this could be a candidate for research.
Unlike the high-maintenance hybrid tea roses, these ground cover forms were developed so they could be used in large quantities without too much fuss. There is no need to selectively prune limbs to correct the plant form. Landscapers will sheer them; not exactly the best solution but practical, efficient, and the shrubs will recover. Really the primary hurtle to specifying them in a California's landscapes is water use. While roses can withstand bouts of drought, they perform best with moderate water throughout their growing cycle. Unless, of course, it is a mysterious rose taking over a lifeless, drought-stricken cemetery.
The following facts are general to ground cover roses; I recommend learning more about individually named cultivars for specific growth habits, color, and performance.
Anthony Tesselaar Plants has this helpful video for understanding the different forms that can be available to designers and gardeners:
Botanical Name: Rosa (ground cover forms)
Rosa: Classical Latin name
Common Name: Ground cover rose
Family Name: Rosaceae
Origin: Unclear at time of posting.
Positioning: Foreground, middle ground, slopes, ground plane
Garden Themes: Mediterranean, cottage, rose, commercial, park
Uses: Border, mass, ground cover, embankment cover, informal hedge
Type: Deciduous shrub
Size: 2' tall by 2' to 6' wide (see individual cultivars and brands)
Outstanding Feature(s): Flower, form
Stem: Green, thorns
Type: Odd pinnately compound
Shape: Leaflets: elliptic in sets of 3 to 7
Color: Dark green
Flower: Summer to Autumn. Miniature to small, double and single, typically in clusters and wide range of colors.
Fruit: Unclear at time of posting if any produce rose hips.
cultural requirements, tolerances & problems
Sunset Zones: All zones
USDA Zones: 4-11
WUCOLS SF Bay Area Hydro Zone: Moderate
Texture: Sand, silty loam, clay, well composted
Moisture Retention: Well-drained, minor drying
Branch Strength: N/A
Disease: Powdery mildew, rust, spot (many cultivars are resistant)
citations & attributions
Bayton, R. (2019). The Royal Horticultural Society's the Gardener's Botanical: An Encyclopedia of Latin Plant Names. London: Mitchell Beazley.
Gardenia. "Rosa Popcorn Drift® (Groundcover Rose)." Gardenia: Creating Gardens (no known address). Accessed on September 12, 2021, from https://www.gardenia.net/plant/rosa-popcorn-drift.
JUSTIA Patents. "Rose plant named Weopop." Justia, Mountain View. Accessed on September 12, 2021, from https://patents.justia.com/patent/PP6809.
Norris Brenzel, K. (Ed.). (2012). The New Sunset Western Garden Book. New York: Time Home Entertainment, Inc.
Plant Finder. "Rosa 'Meicoublan' WHITE MEIDILAND." Missouri Botanical Garden, St. Louis. Accessed on September 12, 2021, from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=252473&isprofile=0&.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on September 12, 2021.
Cemetery find by TELCS.