A retaining wall is a structural backbone, but without the right plant life draped over its face, it looks like a raw scar on the landscape. The problem is that erosion washes soil from between the blocks, and many plants simply can’t handle the lean, dry, exposed conditions a wall creates. You need species that root deep into crevices, cascade to soften hard edges, and thrive on neglect.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I spend weeks comparing grow-zone specs, studying root architectures, and analyzing owner feedback to find the plants that actually survive on a wall face rather than just sitting on a garden-center shelf.
This guide breaks down five proven performers that anchor loose soil, tolerate drought, and turn an engineered structure into a living tapestry, giving you the confidence to choose the right best retaining wall plants for your zone and sunlight conditions.
How To Choose The Best Retaining Wall Plants
Picking plants for a retaining wall is different from picking plants for a flat flower bed. The wall face is steep, dries out faster, and subjects roots to constant downward pull. You need species that grab hold and spread without overwhelming the structure.
Growth Habit: Cascading vs. Upright
Cascading plants like creeping rosemary or trailing jasmine soften the wall face and hide block lines. Upright clumpers like Liriope work best along the top edge, where they create a dense border that prevents soil from washing over the cap. Mix both for a layered look.
Root Density and Soil Binding
A fibrous, mat-forming root system holds soil particles together far better than a single taproot. Sedum mats and creeping rosemary produce a dense web of fine roots that lock into crevices between blocks. This is the single most important trait for erosion control on a wall.
Sunlight and Zone Hardiness
South-facing walls bake in full sun and reflect heat upward, so you need plants rated for full sun and high heat (zones 8-11 for jasmine and rosemary). North-facing or shaded walls suit partial-shade lovers like Liriope. Always match the plant’s USDA zone to your local climate to avoid winter dieback.
Water Needs and Drought Tolerance
Wall faces shed water quickly. Choose drought-tolerant species that can survive dry spells once established. Overwatering a wall plant leads to root rot because the soil behind the wall drains poorly. Rosemary, sedum, and Liriope all handle lean watering schedules.
Quick Comparison
On smaller screens, swipe sideways to see the full table.
| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Sedum Groundcover Mat | Premium | Instant living wall coverage | 10×20 inch pre-grown mat | Amazon |
| Creeping Rosemary | Mid-Range | Cascading over wall face | Spreads 4-8 ft wide | Amazon |
| Star Jasmine Large Leaf | Mid-Range | Fragrant climbing cover | Height up to 20 ft | Amazon |
| Blanket Flower Gaillardia | Entry-Level | Colorful top-edge border | 4-8 inch starter plants | Amazon |
| Variegated Liriope (18 Pack) | Value Pack | Mass edging along wall top | 18 plants per pack | Amazon |
In‑Depth Reviews
1. Sedum Groundcover Mat (10 x 20 in)
This is the closest thing to instant gratification for a retaining wall. The 10×20 inch mat is already mature, with multiple sedum varieties knitted together into a single living carpet. You can cut sections with a knife to fit individual wall niches or lay the whole mat over a soil-filled terrace. Because sedum is a succulent, it stores water in its leaves and shrugs off the punishing heat reflected off stone or concrete blocks. The mat handles zones 3 through 9, making it one of the most versatile cold-hardy options available.
The root system is a dense fibrous mat that binds to soil and small rock crevices almost immediately after planting. Within a few weeks, the sedum spreads via runners, filling gaps between stones. The multicolor foliage — greens, yellows, reds — provides visual interest even when nothing is blooming. A portion of every purchase also goes toward shelter animals, which is a nice bonus.
One nuance: the mat arrives as a single continuous tile. If you need to cover a long, narrow wall top, you may have to buy multiple mats and seam them together. Also, while sedum is drought-tolerant, it can rot if water pools behind the wall — ensure drainage holes or gravel backfill exist. For a low-effort, high-impact wall covering, this mat is unmatched.
What works
- Ready-to-install living mat eliminates weeks of waiting for seedlings
- Root mat binds soil immediately, reducing erosion behind wall blocks
- Thrives in full sun reflected off stone surfaces without scorching
What doesn’t
- Single tile size limits coverage on long walls without multiple mats
- Overwatering or poor drainage can cause root rot quickly
- Not a cascading plant — best for top or terrace use, not face draping
2. Creeping Rosemary (3 Starter Plants)
Creeping rosemary is a powerhouse for any retaining wall that gets full sun. The ‘Prostratus’ cultivar stays low — maturing at 2-3 feet tall — but spreads aggressively to 4-8 feet wide, creating a waterfall of aromatic needle-like foliage. The blue flowers appear from late winter through spring, attracting bees while you harvest sprigs for the kitchen. These 2.5-inch nursery cubes come three per order, giving you enough material for a 4- to 6-foot wall section if spaced properly.
The root system is fibrous and tenacious, weaving into the gaps between blocks and holding soil even on steep angles. Once established after one growing season, this plant becomes seriously drought-tolerant — you can water once a week or less. The evergreen foliage keeps the wall looking green all winter in zones 8-11. Deer rarely touch it, and the strong scent makes it naturally pest-resistant.
Be aware that creeping rosemary is not for cold climates. It dies below 20°F, so northern gardeners cannot use it as a perennial. Also, the growth can be vigorous — you may need to trim it twice a year to prevent it from swallowing adjacent plants. For warm-zone walls, this is the best cascading option for combining erosion control with culinary value.
What works
- Dense fibrous roots grip wall crevices and prevent soil washout
- Aromatic foliage is deer-resistant and useful for cooking
- Blue flowers and year-round green foliage provide multi-season interest
What doesn’t
- Not winter-hardy outside zones 8-11 — dies in freezing temps
- Can outgrow its space within two seasons without regular pruning
- Starter cubes are small; takes a full season to establish dramatic coverage
3. Star Jasmine Large Leaf (2.5 Quart)
If your retaining wall has a fence, trellis, or post above it, star jasmine turns the entire assembly into a vertical garden. This 2.5-quart plant arrives with a robust root ball and several growth tips ready to climb. The dark green glossy leaves form a dense backdrop for the star-shaped white flowers that emit a sweet, heady fragrance from spring through summer. Mature spread of 3-4 feet means one plant can cover a large section of wall face and the structure above.
The vining habit allows it to scramble up or drape down depending on how you train it. On a retaining wall, you can let it cascade over the face, but its real strength is climbing up from the base to soften both the wall and the fence above. It prefers full sun for maximum blooming but tolerates partial shade. The plant is heavy — the 2.5-quart pot and moist soil weigh about 6 pounds — so expect a substantial starter.
Star jasmine is not a true jasmine (it’s Trachelospermum jasminoides) but behaves similarly. It needs regular watering during the first season — 2-3 times per week — to develop its deep root system. After year two, it becomes moderately drought-tolerant. The main downside is zone restriction: it reliably survives only in zones 8-11. In colder areas, it must be grown in a container and brought indoors. For sheer fragrance and vertical coverage, this plant is hard to beat.
What works
- Intense fragrance fills the area around the wall during bloom season
- Large 2.5-quart pot ensures a strong start with minimal transplant shock
- Versatile growth — climbs trellises or cascades over wall face
What doesn’t
- Needs consistent watering 2-3 times weekly during first growing season
- Not cold-hardy below zone 8; fails in freezing winters
- Can become leggy if not pruned annually after flowering
4. Blanket Flower Gaillardia Arizona Sun (2 Plants)
Blanket flower is not a cascader, but it belongs on the top edge of a retaining wall for a burst of red-and-yellow color that lasts from early summer through fall. Each plant arrives in a 4-inch pot, 4 to 8 inches tall, with a well-developed root system. Gaillardia is a short-lived perennial that thrives in poor, well-drained soil — exactly the conditions found on top of a wall. It blooms heavily without deadheading, and the flowers attract bees, butterflies, and other pollinators.
The root system is a taproot with branching fibrous laterals, which is decent for erosion control along the top edge but not suitable for the wall face itself. Plant it along the cap stones or in the soil pocket behind the wall, and it will form a dense clump that holds the topsoil in place during rain. It tolerates drought once established and needs only moderate watering. The Arizona Sun cultivar is particularly compact, staying under 12 inches tall, so it won’t flop over and block the view of lower plantings.
Two plants provide enough material for about 2-3 feet of wall top. If you have a longer wall, you’ll need multiple packs. Also, these are starter plants, so they need a few weeks to bulk up before they look substantial. In zones 3-10, this is a reliable, low-cost way to add high-impact color to the retaining wall’s upper edge.
What works
- Long bloom season from early summer to frost with no deadheading needed
- Compact 12-inch height is perfect for wall top without flopping over
- Thrives in poor, fast-draining soil common on wall caps
What doesn’t
- Not a cascading plant — limited to top-edge use only
- Starter plants are small; requires several weeks to reach full size
- Short-lived perennial (2-3 years) before needing replacement
5. Variegated Liriope Grass (18 Pack)
Liriope, or lilyturf, is the workhorse of retaining wall edges. This 18-pack of variegated Liriope gives you enough plants to cover a 15- to 20-foot wall top with a dense, evergreen border. The green-and-white striped leaves grow 12-18 inches tall and spread into clumps that knit together over time. In late summer, purple flower spikes appear above the foliage, adding a subtle second layer of interest. It is one of the few plants that looks great from spring through winter without any effort.
The root system is a network of thick, fibrous rhizomes that hold soil tenaciously. Planted along the back edge of a wall cap, Liriope creates a living barrier that stops soil from washing over the face during heavy rain. It prefers partial to full shade — ideal for north-facing walls or walls shaded by a fence. Once established after one season, it becomes drought-tolerant and needs only occasional water. It handles zones 5-10, making it the best cold-weather option in this lineup.
The 18-pack is a budget-friendly way to buy in bulk, but these are bare-root or starter plugs, not fully mature plants. They will look sparse for the first month. Space them 8-12 inches apart for solid coverage within one growing season. Also, Liriope can be aggressive in rich soil — if your wall top has amended garden soil, you may need to divide clumps every 3-4 years. For sheer volume of coverage per dollar, this pack is the best value.
What works
- 18 plants provide mass coverage for long wall sections at low cost
- Evergreen variegated foliage adds year-round color and texture
- Cold-hardy to zone 5 — survives winters most other wall plants cannot
What doesn’t
- Starter plugs are small; takes 4-6 weeks to establish visible coverage
- Can spread aggressively in rich soil, requiring division every few years
- Best suited for wall top edging, not cascading down the wall face
Hardware & Specs Guide
Root System Type
The root architecture determines erosion control power. Fibrous mat roots (sedum, creeping rosemary) create a dense web that holds soil particles together across the wall face. Rhizomatous roots (Liriope) spread horizontally and lock top-edge soil in place. Taproots (blanket flower) anchor deep but do not bind surface soil well. For wall faces, prioritize fibrous mat rooters.
USDA Hardiness Zone
Every plant has a zone range. Check your local zone before buying — a plant rated for zones 8-11 will die in a zone 6 winter if left outside. Sedum mat covers zones 3-9, Liriope covers 5-10, while creeping rosemary and star jasmine are limited to zones 8-11. Zone mismatch is the most common reason wall plants fail after one season.
Sunlight Exposure
Wall orientation drastically changes microclimate. South and west-facing walls reflect intense heat and light — only full-sun plants like sedum, creeping rosemary, and blanket flower survive. North-facing or shaded walls suit Liriope, which prefers partial to full shade. Jasmine handles partial shade but blooms less. Measure the wall’s sun hours before choosing.
Mature Spread and Height
Wall plants need to fit their allotted space without overcrowding. Creeping rosemary spreads 4-8 feet wide, making it ideal for large walls but hazardous for small ones. Liriope clumps stay 12-18 inches tall and spread slowly, perfect for tidy edging. Sedum mats stay low (under 6 inches) and spread via runners. Match mature dimensions to your wall length to avoid constant pruning.
FAQ
Can I plant directly into the gaps between retaining wall blocks?
How many plants do I need for a 10-foot retaining wall?
Will retaining wall plants damage the wall structure over time?
What is the best plant for a shady north-facing retaining wall?
Final Thoughts: The Verdict
For most gardeners, the best retaining wall plants winner is the Sedum Groundcover Mat because it provides instant erosion control, thrives across zones 3-9, and requires almost no maintenance once placed. If you want a cascading fragrant display that doubles as a kitchen herb, grab the Creeping Rosemary. And for mass top-edge coverage on a budget in cooler climates, nothing beats the Variegated Liriope 18-pack.