Landscaping
Best Drought-Tolerant Ground Covers for Sustainable Landscapes
The Shift Toward Sustainable Ground Covers
For decades, the American landscape has been dominated by the sprawling, emerald-green expanse of traditional turfgrass. While a manicured lawn has its place, the environmental and financial costs of maintaining it are becoming increasingly difficult to justify. Turfgrass requires copious amounts of water, synthetic fertilizers, and gas-powered mowing, all of which contribute to resource depletion and ecological runoff. According to the Environmental Protection Agency (EPA), outdoor water use accounts for nearly a third of residential water consumption, with landscape irrigation making up the vast majority of that figure.
This reality has sparked a massive shift toward sustainable landscaping and xeriscaping. One of the most effective strategies for reducing water consumption while maintaining a lush, vibrant yard is replacing high-maintenance turf with drought-tolerant ground covers. Selecting the right species for your specific microclimate, soil type, and functional needs is the cornerstone of successful landscape design. Programs like the Texas A&M Earth-Kind Landscaping initiative emphasize that choosing regionally adapted, water-wise plants drastically reduces the need for supplemental irrigation and chemical interventions.
In this guide, we will explore the best drought-tolerant ground cover species, comparing their characteristics, ideal use cases, and planting requirements to help you make an informed decision for your landscape.
Top Drought-Tolerant Ground Cover Species
When selecting a ground cover, it is crucial to look beyond just water tolerance. You must also consider foot traffic, sun exposure, and aesthetic appeal. Below are four exceptional species that thrive in low-water conditions.
1. Creeping Thyme (Thymus serpyllum)
Creeping thyme is a woody, perennial herb that forms a dense, low-growing mat, making it an excellent substitute for grass in low-traffic areas. It thrives in full sun and well-draining soil, producing tiny, fragrant leaves that release a pleasant aroma when brushed against. In late spring and early summer, it erupts in a carpet of pink, purple, or white flowers that are highly attractive to bees and other pollinators.
- Best Cultivars: 'Elfin' (extremely low-growing, under 2 inches), 'Pink Chintz' (vibrant pink blooms), and 'Woolly' (silver-grey foliage, highly drought-resistant).
- Spacing & Coverage: Plant plugs 6 to 8 inches apart. A single flat of 50 plugs can cover approximately 25 square feet.
- Foot Traffic: Light. It can handle the occasional footstep but will not survive heavy, daily play areas.
- Cost: Plug trays typically cost $40 to $60, making it an economical choice for large areas if you are willing to wait a season for full establishment.
2. Stonecrop / Sedum (Sedum spurium & Sedum album)
Sedums are succulent perennials that store water in their fleshy leaves, making them virtually indestructible once established. They are the undisputed champions of hot, dry, and poor-soil environments. Sedum is particularly useful for stabilizing soil on slopes, rock gardens, and green roofs where traditional irrigation is impractical.
- Best Cultivars: 'Dragon's Blood' (features deep red foliage in autumn), 'Angelina' (bright chartreuse, needle-like leaves), and 'John Creech' (a low, dense grower with pink flowers).
- Spacing & Coverage: Space 1-gallon containers 12 to 18 inches apart. Sedum spreads rapidly via runners and offsets.
- Foot Traffic: None to very light. The succulent leaves are brittle and will crush easily under heavy weight.
- Cost: 1-gallon pots range from $8 to $15 each. Because they spread quickly, you need fewer plants per square foot compared to thyme.
3. Liriope / Monkey Grass (Liriope spicata & Liriope muscari)
If you need a ground cover that mimics the texture and appearance of traditional grass but requires a fraction of the water and maintenance, Liriope is an outstanding choice. It features arching, grass-like leaves and produces spikes of purple or white flowers in late summer, followed by dark berries. Unlike many drought-tolerant plants, Liriope is remarkably shade-tolerant, making it perfect for planting under the canopy of large trees.
- Best Cultivars: 'Big Blue' (clumping, deep green), 'Variegata' (striking green and white stripes), and 'Silver Dragon' (slender, silver-green blades).
- Spacing & Coverage: Plant bare-root divisions or 1-gallon pots 12 inches apart in a staggered grid pattern.
- Foot Traffic: Moderate. It can handle occasional walking, though it is best suited for borders and shaded pathways.
- Cost: Bare-root divisions are highly cost-effective, often sold in bundles of 50 for around $30 to $50.
4. Creeping Rosemary (Rosmarinus officinalis 'Prostratus')
For landscapes in warmer climates (USDA Zones 8-10), creeping rosemary offers a beautiful, cascading evergreen presence. It spills elegantly over retaining walls, rockeries, and raised beds. Beyond its aesthetic value and extreme drought tolerance, it provides culinary herbs and emits a strong, pest-repelling fragrance.
- Best Cultivars: 'Prostratus' (the standard creeping variety), 'Huntington Carpet' (dense, compact growth), and 'Irene' (excellent purple-blue flowers).
- Spacing & Coverage: Space plants 24 to 36 inches apart. They can easily spread 4 to 6 feet wide at maturity.
- Foot Traffic: None. Best used as a visual and structural ground cover on slopes or walls.
- Cost: 1-gallon or 2-gallon shrubs cost between $12 and $25 each.
Species Comparison Chart
Use the table below to quickly compare the core characteristics of these drought-tolerant species to find the best fit for your landscape design.
| Species | Botanical Name | Hardiness Zones | Sun Exposure | Water Needs | Traffic Tolerance |
|---|---|---|---|---|---|
| Creeping Thyme | Thymus serpyllum | 4 - 9 | Full Sun | Very Low | Light |
| Stonecrop | Sedum spurium | 3 - 9 | Full to Part Sun | Extremely Low | None |
| Liriope | Liriope spicata | 5 - 10 | Shade to Part Sun | Low to Moderate | Moderate |
| Creeping Rosemary | Rosmarinus 'Prostratus' | 8 - 10 | Full Sun | Very Low | None |
How to Select the Right Variety for Your Zone
Choosing a plant based solely on its "drought-tolerant" label is a common landscaping mistake. A plant that thrives in the arid heat of Arizona may fail completely in the humid, clay-heavy soils of the Southeast, even if both regions experience summer droughts. To make scientifically backed selections, consult the Water Use Classification of Landscape Species (WUCOLS) database. Managed by the University of California, WUCOLS evaluates thousands of landscape plants and categorizes their water needs based on specific regional climates and evapotranspiration rates.
Pro Tip: Always match the plant's native soil preferences to your site. If you have heavy clay soil, avoid Mediterranean plants like creeping rosemary unless you heavily amend the soil with pumice and gravel to improve drainage. Sedum and thyme will rot in winter if their roots sit in waterlogged clay.
Planting and Establishment Tips
Even the most drought-tolerant plants require consistent moisture during their establishment phase. The root system must grow deep into the soil profile before the plant can survive on rainfall alone. Follow these actionable steps for a successful planting:
1. Site Preparation and Turf Removal
If you are converting a lawn area, do not simply till the grass under, as this will bring weed seeds to the surface and lead to years of maintenance headaches. Instead, use the sheet mulching method:
- Mow the existing grass as short as possible.
- Cover the area with overlapping layers of plain cardboard (remove all tape and staples).
- Top the cardboard with 3 to 4 inches of high-quality compost or arborist wood chips.
- Allow the area to sit for 6 to 8 weeks. The grass will smother and decompose, leaving you with a nutrient-rich, weed-free planting bed.
2. Soil Amendment and Planting
Test your soil drainage by digging a 12-inch hole and filling it with water. If it drains in under an hour, your soil is sandy; if it takes more than 4 hours, you have heavy clay. For drought-tolerant species, aim for a loamy, well-draining profile. Amend heavy clay with expanded shale or crushed granite, not just peat moss, which can retain too much moisture.
When planting plugs or pots, dig a hole twice as wide as the root ball but no deeper. The crown of the plant (where the stems meet the roots) must sit slightly above the surrounding soil grade to prevent crown rot.
3. The Establishment Watering Schedule
Drought tolerance is a trait of mature plants. During the first 12 weeks, follow this watering schedule:
- Weeks 1-2: Water lightly every day or every other day to keep the top inch of soil moist.
- Weeks 3-6: Water deeply twice a week, encouraging roots to grow downward.
- Weeks 7-12: Water deeply once a week. By the end of this period, the plants should be established and ready to rely primarily on natural rainfall, requiring supplemental watering only during extreme heat waves.
Conclusion
Transitioning from a traditional turf lawn to a diverse, drought-tolerant ground cover landscape is one of the most impactful upgrades a homeowner can make. By carefully selecting species like creeping thyme, sedum, liriope, or creeping rosemary based on your specific hardiness zone, sun exposure, and soil type, you can create a dynamic, textured, and ecologically beneficial yard. Not only will you drastically reduce your water bills and weekend maintenance chores, but you will also foster a healthier local ecosystem by providing vital habitats for pollinators and reducing chemical runoff into local waterways.
