The standout feature of 'Grace Ward' is its intensely vibrant, gentian-blue flowers. Compared to other Lithodora varieties, the blue is often described as deeper and more striking. It also boasts a long bloom period, typically from late spring through summer (and often with sporadic reblooming later in the season). Its vigorous, spreading habit makes it an excellent groundcover, quickly filling in spaces and cascading beautifully over walls or containers.

Description and Details:

• Appearance: A low-growing, evergreen sub-shrub (meaning it has woody stems at the base but softer growth above) with a mat-forming habit.
• Flowers: Five-petaled, star-shaped flowers that are a brilliant, deep blue. They are relatively small (about ½ to ¾ inch across) but appear in profuse clusters.
• Foliage: Small, narrow, hairy, dark green leaves. The texture is slightly rough.
• Size: Typically grows 6-12 inches tall and spreads 18-24 inches (or more) wide. It is a fairly fast grower.
• Growth Habit: Trailing and spreading, forming a dense mat.
• Blooming Time: Late spring to early summer, often with sporadic reblooming throughout the summer and into early fall.

Native Habitat:

Lithodora diffusa is native to southwestern Europe, specifically rocky, mountainous areas of Spain and France. This explains its preference for well-drained soil and its tolerance for somewhat dry conditions. 'Grace Ward' is a cultivated variety, not found in the wild.

Landscaping Design Tips:

• Groundcover: Excellent for filling in spaces, suppressing weeds, and providing a splash of vibrant color. Ideal for rock gardens, slopes, and the front of borders.
• Rock Gardens: A classic choice, as it thrives in the well-drained conditions and complements the rocky aesthetic.
• Slopes and Banks: Helps with erosion control due to its spreading, mat-forming habit.
• Cascading over Walls: The trailing stems look beautiful spilling over retaining walls or raised beds.
• Containers: Works well in containers, either alone or as a "spiller" element in mixed plantings.
• Edging: Can be used to edge pathways or borders, providing a soft, colorful line.
• Companion Plants: Pairs well with plants that share similar sun and soil preferences, such as:
  • Low-growing Sedums (Stonecrop)
  • Thyme (especially creeping varieties)
  • Armeria (Sea Thrift)
  • Aubrieta
  • Dianthus (Pinks)
  • Smaller, drought-tolerant ornamental grasses.
  • Lavender
  • Rosemary

Avoid pairing it with plants that require consistently moist, rich soil, as these conditions are detrimental to Lithodora.

Planting and Care:

• Sunlight: Prefers full sun (at least 6 hours per day) for best flowering. It can tolerate partial shade, but flowering will be reduced. In very hot climates, some afternoon shade is beneficial.
• Soil: Crucially, requires well-drained soil. It will not tolerate soggy, heavy clay. Amend heavy soils with plenty of organic matter (compost, well-rotted manure) and grit (perlite, coarse sand, or fine gravel) to improve drainage. A slightly acidic to neutral pH (6.0-7.0) is ideal.
• Watering: Water regularly, especially during establishment. Once established, it is relatively drought-tolerant. Allow the soil to dry out slightly between waterings. Overwatering is a common cause of problems.
• Fertilizing: Generally, does not require heavy feeding. A light application of a balanced, slow-release fertilizer in spring is usually sufficient. Avoid high-nitrogen fertilizers, which can promote excessive leafy growth at the expense of flowers. A fertilizer formulated for acid-loving plants can be beneficial.
• Pruning: Lightly shear back the plant after flowering to maintain a compact shape and encourage bushier growth. Remove any dead or damaged stems.
• Winter Hardiness: Hardy in USDA zones 6-9. In colder zones, it may need winter protection (mulch around the base of the plant). Good snow cover can also act as insulation.
• Propagation: Can be propagated by softwood cuttings taken in late spring or early summer, or by semi-hardwood cuttings taken in summer. Division is possible, but not always successful due to the plant's woody base.

Taxonomy:

• Kingdom: Plantae
• Division: Magnoliophyta
• Class: Magnoliopsida
• Order: Boraginales
• Family: Boraginaceae (Borage Family)
• Genus: Lithodora
• Species: diffusa
• Cultivar: 'Grace Ward'

Morphology:

• Roots: Fibrous root system.
• Stems: Woody at the base, becoming more herbaceous towards the tips. Trailing and spreading.
• Leaves: Simple, alternate, lanceolate (lance-shaped), sessile (lacking a stalk), with a rough, hairy texture.
• Flowers: Actinomorphic (radially symmetrical), with five fused petals forming a funnel or star shape. Five stamens and a single pistil.
• Fruit: Small, dry nutlets.

Popular Varieties (Other than 'Grace Ward'):

• 'Heavenly Blue': Another popular variety, with bright blue flowers, but often considered slightly less intense in color than 'Grace Ward'. It may be slightly more compact.
• 'Star': Features blue flowers with a distinct white star in the center.
• 'White Star': Features bright, white flowers.
• 'Pete's Choice': Deeper blue flowers with the same great growth patterns.

Other Insights Gardeners Need to Know:

• Deer Resistance: Generally considered deer-resistant, although no plant is completely deer-proof.
• Pest and Disease Problems: Relatively pest-free. The main problems are usually related to overwatering or poor drainage, which can lead to root rot. Spider mites can occasionally be a problem in hot, dry conditions.
• Lifespan: Lithodora is not exceptionally long-lived. Plants may start to decline after 3-5 years and may need to be replaced. Regular pruning and good care can help extend their lifespan.
• Acidity Lovers: The addition of soil sulfur or an acid loving plant fertilizer can assist in the proper nutrients for the plant.

By understanding these details, gardeners can successfully grow and enjoy the vibrant beauty of Lithodora diffusa 'Grace Ward' in their landscapes. The key is providing the right conditions, especially well-drained soil and ample sunlight.