21 Colorful Rock Garden Plants That Thrive in Poor Soil

Nov 04, 2024

Use these tough but pretty perennials and succulents to create a super low-maintenance landscape.

Andrea Beck served as garden editor at BHG and her work has appeared on Food & Wine, Martha Stewart, MyRecipes, and more.

These pretty, low-maintenance rock garden plants make top choices for any well-draining, gravelly spot. Use them to create a colorful rock garden, but these tough plants also work well in gravel gardens, alpine gardens, pockets in dry-stack walls, and between stepping stones. Count on these low-growing perennials and succulents to produce vibrant flowers and foliage, even in poor soil, drought, and heat.

Commonly called basket of gold, perennial alyssum (Aurinia saxatilis) makes a beautiful wall or rock garden plant. Every spring, it develops masses of cheerful yellow flowers that look terrific tucked between rocks and boulders. In warmer regions, this plant can be short-lived, so replant every year or two. You can grow perennial alyssum from seeds or nursery transplants.

Growing Conditions: Full sun in well-drained soil

Size: Up to 12 inches tall

Zones: 4-7

Just as you would in a traditional perennial garden, including ornamental grasses in your rock or wall garden is important for adding texture and interest throughout the year. They keep the color show going while other plants come in and out of bloom. One favorite for a rock garden is blue fescue (Festuca glauca). This dense, clumping grass grows just 12 inches tall and has rich blue foliage highlighted with buff-color flower stalks in the late summer. Blue fescue thrives in dry conditions and mixes well with other rock garden plants.

Growing Conditions: Full sun in well-drained, dry soil

Size: Up to 12 inches tall

Zones: 4-8

Though it stays tiny, blue star creeper (Isotoma fluviatilis) should be on your must-have list for rock or wall gardens. This handsome perennial develops tiny green leaves forming a solid mat that can take light foot traffic. Blue star creeper is covered in the spring with pretty, pale blue star-shaped flowers. Blue star creeper prefers slightly moist soil, making it a great partner for Irish moss in moister climates.

Growing Conditions: Full sun to part shade in well-drained soil

Size: Up to 4 inches tall

Zones: 5-9

A reliable spring bloomer, candytuft (Iberis sempervirens) produces a stunning carpet of snow-white flowers atop bright evergreen foliage. As a bonus, when the flowers mature, they fade to light pink, which gives the plant a second show of color. Candytuft is an easy-care perennial that’s deer- and drought-resistant. After blooming, remove the spent flowers and enjoy the plants’ rich green leaves right through the winter.

Growing Conditions: Full sun in well-drained soil

Size: Up to 6 inches tall

Zones: 3-8

Just when you thought winter would never end, the jewel-like flowers of creeping phlox (Phlox subulata) burst into bloom in early spring. An ideal rock garden plant, creeping phlox thrives in poor, dry soil that drains quickly after rain. Creeping phlox produces carpets of blue, purple, rose, pink, or bicolor blooms. The plants also have dark, needlelike, evergreen foliage that remains attractive year-round.

Growing Conditions: Full sun in well-drained, dry soil

Size: Up to 6 inches tall

Zones: 3-9

Prized for both its colorful foliage and flowers, deadnettle (Lamium maculatum) makes a superb rock garden plant, especially in shady locations. This handsome creeper comes in a variety of foliage colors, including silver, chartreuse, green, and bicolor. The pink or white flowers appear from May to July and are also deer-resistant. When happy, deadnettle can spread quickly but don’t worry because the plants are easy to control with an occasional haircut.

Growing Conditions: Full to part shade in well-drained, slightly moist soil

Size: Up to 12 inches tall

Zones: 3-8

If you live in a frost-free region, be sure to include Euphorbia in your rock garden. This fantastic family of succulents comes in a seemingly endless selection of shapes, sizes, and colors. They are extremely heat- and drought-resistant and have shallow root systems that allow you to easily tuck them into the tight spots between rocks and boulders. In the north, you can still enjoy Euphorbia by planting them in a large, flat dish and setting it in the center of the garden. Then, when frost threatens, just bring it indoors.

Growing Conditions: Full sun and well-drained, dry soil

Size: Most are 4-8 inches tall, but some can reach up to 6 feet

Zones: 9-11 (depends on variety)

These adorable, ground-hugging plants are a lot like potato chips; you can’t stop with just one. Hens-and-chicks (Sempervivum spp.) come in various shapes, sizes, and colors, so they’re super collectible. Each plant (the hen) sends out babies (the chicks) on short runners, eventually forming a tight mat of pretty foliage. Hens-and-chicks are drought tolerant and are small enough to be tucked into even the tiniest sunny nook or cranny. The chicks can be separated from the hen and be replanted in other locations (they’re also popular for growing indoors as houseplants).

Growing Conditions: Full sun in well-drained soil

Size: Up to 12 inches tall

Zones: 4-9 (depends on variety)

Resistant to heat, drought, poor soil, and salt, the ice plant (Delosperma cooperi) is about as indestructible as you can get. This mat-forming perennial grows 3-6 inches tall and can spread two feet or more wide. Ice plant has fleshy gray-green foliage almost hidden by an abundance of jewel-tone, daisylike blooms in purplish-pink, yellow, white, orange, or red. Tuck the ice plant between boulders and watch it slowly frame the stones with brilliant color. Ice plants are more cold-hardy in drier, western landscapes.

Growing Conditions: Full sun in well-drained soil

Size: Up to 6 inches tall

Zones: 6-11

Because most rock garden plants thrive in dry soil, it can be challenging to grow in wetter climates such as the Pacific Northwest. However, perennials such as Irish moss (Sagina subulata) love moisture and are a great option for those regions. Irish moss gets its name from its soft, bright green, mosslike foliage that forms a mat so thick you can actually walk on it. In the spring, the plants are accented with tiny star-like white flowers. Tuck Irish moss between stones and water once weekly if rainfall is scarce.

Growing Conditions: Full sun to part shade in consistently moist soil

Size: Up to 1 inch tall

Zones: 4-7

Commonly used as a groundcover, periwinkle (Vinca minor) also works well in a rock or wall garden. This handsome, evergreen trailer produces lavender-blue flowers in late spring and early summer. This periwinkle prefers part shade and slightly moist soil, so it’s one of the best options for rock or wall gardens located under tall trees.

Test Garden Tip: The plants can spread quickly and are considered invasive in parts of the southeast.

Growing Conditions: Full to part shade in well-drained, slightly moist soil

Size: Up to 6 inches tall

Zones: 4-8

Unlike its culinary cousins, red creeping thyme (Thymus serpyllum) won’t play a starring role in your kitchen, but it will add tons of color and interest to your rock garden. This gorgeous ground hugger will quickly fill in between paving stones or rock walls. Tough enough to take light foot traffic, this rugged perennial will release its rich fragrance every time its leaves are crushed. Red creeping thyme is smothered with tiny lavender-red blooms in the summer and grows well in containers.

Growing Conditions: Full sun in well-drained soil

Size: Up to 6 inches tall

Zones: 4-9

Also called arabis, rock cress (Aubrieta deltoidea) gets its name because it thrives in the thin ribbon of soil wedged between boulders. This pretty creeper produces masses of cheerful pink or white flowers in the spring. It can tolerate heat and drought and is deer-resistant. Rock cress makes a great container plant, too. Shear back plants after flowering to encourage denser growth.

Growing Conditions: Full sun to part shade in well-drained soil

Size: 4 to 6 inches tall

Zones: 4-8

If you want a “plant it and forget it” perennial for your rock garden, you can’t go wrong with sedums. These tough-as-nails plants come in a wide variety of colors and shapes and will quickly take root in any sunny, rocky location. Plus, most types produce nectar-rich, white, pink, or mauve flower heads in the summer and fall that lure colorful butterflies to your garden. Ground-hugging sedums are often sold in mixed “tiles” that, like sod, you can cut up and tuck into any space. Look for sedum tiles at your local garden center.

Growing Conditions: Full sun in well-drained, dry soil

Size: Up to 3 feet tall

Zones: 4-8

The pure white flowers of snow-in-summer (Cerastium tomentosum) appear in cloudlike drifts from late May to mid-June. Snow-in-summer also has soft gray foliage that looks terrific even when the plants are not blooming. If planted in a sunny, well-drained location, this plant will spread slowly through your rock or vertical garden. It doesn’t like heat and humidity, so it may need to be replanted every year or so in the southern portion of its range. Shear off flowers after they fade to keep the plants looking their best.

Growing Conditions: Full sun in well-drained soil

Size: Up to 12 inches tall

Zones: 3-10

Make your rock garden sparkle with a generous helping of soapwort (Saponaria ocymoides). During colonial times the sap of this pretty plant was boiled to form a sudsy soap used to launder clothes. However, soapwort is prized today for its fragrant pink flowers that lure butterflies to your garden. Soapwort thrives in shallow, rocky soil, so it’s perfect for rock and wall gardens. The flowers appear from July to September; deadhead them as they fade to encourage more blooms.

Growing Conditions: Full sun in well-drained soil

Size: Up to 2 feet tall

Zones: 3-9

Here’s a little charmer that’s a lot tougher than it looks. Thrift (Armeria maritima) is also known as sea pink because it grows wild on ocean-side cliffs, so you know it will tolerate salt spray, heat, and punishing winds. It’s a compact plant with delicate grasslike foliage and showy pink or white ball-like blooms in the spring. Thrift prefers poor soil; the plants may rot if grown in rich or moist soil. Clip away the flowers as they fade to keep plants looking tidy.

Growing Conditions: Full sun and well-drained soil

Size: Up to 3 feet tall

Zones: 4-9

The fuzzy, gray-green leaves of woolly thyme (Thymus pseudolanuginosus) have a soft, carpetlike appearance that contrasts perfectly with hard-edged rocks and boulders. But don’t let its cushionlike appearance fool you; this little plant is tough enough to walk on and will grow just fine between stepping stones or pavers. Woolly thyme grows 3 inches tall and, in midsummer, develops masses of tiny pink, nectar-rich flowers that butterflies will flock to.

Growing Conditions: Full sun in well-drained soil

Size: Up to 3 inches tall

Zones: 5-8

Native to the Rocky Mountains, yellow columbine (Aquilegia chrysantha) produces yellow flowers from spring into summer over a mound of lacy bluish-green foliage. Butterflies, bumblebees, and hummingbirds love to visit the blooms. This species tolerates heat well, especially in the shade, but may go dormant in summer if conditions are too dry. It may be short-lived but will reseed and slowly spread itself around.

Growing Conditions: Part shade, especially during the afternoon, and well-drained soil

Size: 1-3 feet tall

Zones: 4-8

Carson Downing

Native to much of Europe, pasque flower (Pulsatilla vulgaris) is an early-blooming perennial. It forms clumps of fuzzy leaves, a quintessential look in alpine plants. In spring, it produces purple flowers, followed by fluffy-looking seed heads. It may die back by the end of summer but will reappear early the following spring.

Growing Conditions: Full sun to part shade and well-drained soil

Size: under 1 foot tall and wide

Zones: 4-8

Peter Krumhardt

Forming dense mats of low-growing evergreen branches, creeping juniper (Juniperus horizontalis) is ideal for rock gardens and needs next to no care or maintenance once established. It tolerates hot, dry conditions and poor, rocky soil, plus deer leave it alone.

Growing Conditions: Full sun and well-drained, average soil

Size: 1 foot tall and 5-8 feet wide

Zones: 3-9

While you should follow each type of plant's requirement, you can generally water a rock garden every 10 to 12 days. Don't water it in direct sunlight and ensure there's adequate drainage so the plant doesn't get waterlogged.

Not at all! In fact, a rock garden is encouraged for beginners as the cultural conditions are simple to meet and the most time-consuming task would be weeding out each plant. This will diminish over time as the plant establishes and develops itself, leading to fewer weeds to remove.