Botanical Name: Lithodora diffusa ‘Grace Ward’

Common Name: Lithodora

Hardiness Zone: Perennial in Mild Climates (USDA Zones 6–9)

Size: 6–10" Tall × 18–24" Spread

Growth Habit: Low, Spreading, Evergreen Groundcover

Sunlight: Full Sun to Partial Shade (Best Bloom in Full Sun)

Soil: Well-Drained, Acidic Soil Required

Water Needs: Moderate; Consistent Moisture Preferred, Avoid Waterlogging

Bloom Season: Mid to Late Spring (Occasional Rebloom)

Fertilizer: Minimal; Acid-Loving Fertilizer if Needed

Features: Intense Cobalt-Blue Flowers, Evergreen Foliage, Dense Mat-Forming Habit, Deer Resistant

Uses: Ground Cover, Rock Gardens, Slopes, Edging, Acidic Soil Gardens

Patent: ❌ Not Patented

Propagation: ✔ Propagation Allowed

See our complete Lithodora Growth & Care Guide for full care details.

More About Lithodora ‘Grace Ward’

Lithodora ‘Grace Ward’ is best known for its extraordinary cobalt blue flowers, widely considered among the truest and most intense blue blooms available in the garden. In early to mid Spring, the plant becomes nearly blanketed in star shaped flowers that create a striking contrast against its deep green, needle like evergreen foliage. The bloom display is dense and immersive rather than scattered, giving the plant a bold visual presence even though it stays low to the ground. Few groundcovers deliver this level of color saturation in such a compact form. When it reaches peak bloom, the plant almost looks like a pool of blue spreading across the garden bed.

Beyond its flowers, ‘Grace Ward’ forms a tight, low growing mat that remains attractive year round. Its evergreen foliage provides structure and texture even when the plant is not in bloom, which makes it valuable as a permanent landscape plant rather than just a short lived seasonal highlight. The foliage stays compact and slightly glossy, forming a dense carpet that softens hard edges and helps stabilize soil. I especially like the way it gently hugs the ground without looking messy or aggressive.

This growth habit makes it especially well suited for slopes, rock gardens, retaining walls, and the front edges of planting beds where erosion control and long term coverage are important. When it is happy, it slowly spreads to create a cohesive groundcover that feels intentional and polished. In a well designed planting, it can almost look like a living ground layer woven between stones, shrubs, and small perennials.

Why We Like It (Our Trials)

In our trials here in the Upstate, Lithodora ‘Grace Ward’ has proven to be reliable as long as it receives the conditions it prefers. Excellent drainage, acidic soil, and good airflow are the keys to success. When planted in raised beds, slopes, or amended soil where water moves freely, it establishes steadily and maintains dense evergreen foliage through all Seasons. We have learned that drainage is the single biggest factor in its long term performance. In heavier soils it can struggle, but when planted correctly it becomes a very low maintenance plant that improves in appearance each year as the mat slowly fills in. Once established, it has proven surprisingly resilient through both Summer heat and cooler Winter conditions here in Zone 8a.

What truly sets ‘Grace Ward’ apart is its color. The intensity of its blue flowers is something you simply do not see very often in the garden. Every Spring when it comes into bloom, it stops people in their tracks because the color is so pure and saturated. I especially like using it as a specialty groundcover in areas where color impact really matters. It pairs beautifully with Spring bulbs, silver foliage plants, dwarf conifers, and other small evergreens that allow the blue flowers to really shine. This is not a filler plant that disappears into the background. When you give it the right location, it becomes one of the most memorable plants in the entire garden.

Lithodora ‘Grace Ward’ vs. Other Groundcovers

Lithodora ‘Grace Ward’ is often compared to Creeping Phlox. Each has its place in the landscape, but they offer very different looks and growing preferences. ‘Grace Ward’ produces a much deeper and more saturated blue flower color. Creeping Phlox tends to lean toward pastel shades of lavender, pink, or soft purple, while the blooms of lithodora are an intense cobalt blue that immediately catches the eye. Another key difference is foliage. Creeping Phlox is semi evergreen at best in our region, while Lithodora maintains a denser evergreen mat that provides year round texture in the garden. That said, Creeping Phlox is generally more forgiving of soil conditions, whereas ‘Grace Ward’ really prefers acidic soil with excellent drainage.

Blue Star Creeper is another plant people sometimes consider for similar uses, especially in small spaces or between stepping stones. While it does produce tiny blue flowers, the blooms are much smaller and more delicate. Lithodora creates a far stronger visual impact during bloom season because the flowers are larger, more vibrant, and appear in dense clusters across the plant. Blue Star Creeper works well as a subtle filler, but lithodora reads more like a true feature groundcover that anchors the front of a planting. For gardeners who have acidic, well drained soil and want a low growing evergreen plant with truly striking blue flowers, Lithodora ‘Grace Ward’ stands out from most other groundcovers.