Lithodora

Sun

Full sun; light afternoon shade is helpful in hot climates.

Water

Water regularly while establishing, then during extended dry spells. Keep the root zone lightly moist rather than wet; established plants tolerate some drought.

Soil

Acidic to neutral, humus-enriched, sharply drained soil; acidic soil gives the most reliable results. Avoid chalk, heavy wet clay and sites that stay wet in winter.

Height

0.5-1 ft (0.15-0.3 m)

Spread

2-3 ft (0.6-0.9 m)

Flowers

Bright blue flowers from mid-spring into early summer, sometimes followed by scattered flowers later. Some cultivars have white markings.

Foliage

Evergreen. Small, narrow, dark green leaves with a rough, hairy surface, carried on low woody stems.

Growth

Moderate

Care needed

Medium

• Pollinators
• Deer resistant
• Drought tolerant
• Heat tolerant
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.2 ft (0.06 m)

2. After 1 year

   0.4 ft (0.12 m)

3. After 2 years

   0.6 ft (0.19 m)

4. After 3 years

   0.7 ft (0.22 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Moderate

• Plant with the crown at soil level in a freely drained position; use a raised bed if drainage is poor.
• Water at the base during the first growing season, allowing the surface to dry slightly between waterings.
• Apply a light feed for acid-loving plants in spring if growth is weak; avoid heavy feeding.
• Use a thin gravel mulch to keep trailing stems off damp soil, keeping it clear of the crown.
• In cold regions, shelter plants from drying winds and prevent winter waterlogging.

Pruning. Lightly trim the leafy shoots after the main flowering flush to keep the plant compact. Do not cut hard into bare old wood, which may not regrow.

Early spring

Remove dead or winter-damaged shoots, cutting back to healthy leafy growth.

Spring

Plant once the soil is workable and no longer waterlogged; water thoroughly after planting.

Spring

Check for yellowing leaves and apply a light acid-loving plant feed if needed.

Early summer

Lightly trim after the main flowering flush to encourage dense growth.

Summer

Water during prolonged drought and take semi-ripe cuttings from healthy nonflowering shoots.

Autumn

Clear fallen leaves from the mat and check that water drains away from the crown.

Winter

Keep container plants out of standing water and shelter them from severe frost and drying winds.

• Trail it over a low retaining wall where the blue flowers can be seen at eye level.
• Plant between rocks in an acidic rock garden, allowing room for its spreading stems.
• Edge a sunny path with low blue-flowering mats beside dwarf conifers or heathers.
• Grow in a wide container with acidic, free-draining potting mix where garden soil is chalky.

Garden styles it suits: Cottage garden, Alpine rock garden, Dry gravel garden, Coastal, Blues and silvers and Small-space.

Plant it with: Heather, Dwarf pines, Creeping phlox and Blue fescue.

Wildlife: The flowers provide nectar for bees and other visiting insects. It is not a native groundcover in the United States, Canada, the United Kingdom or Australia.

• Root or crown rot in wet soil: improve drainage or replant in a raised bed; discard badly rotted plants.
• Yellow leaves with greener veins in alkaline soil: grow in acidic soil or an ericaceous container mix; chelated iron may offer temporary relief.
• Sparse, woody growth: trim lightly after flowering and replace declining plants with rooted cuttings rather than pruning hard.
• Winter browning or dieback: provide shelter from cold winds, keep winter drainage sharp and remove dead shoots in spring.

Not known to be toxic to people, cats, dogs or horses. Species-specific poisoning information is limited, so do not treat any part as edible; the rough, hairy foliage may irritate sensitive skin.

• Creeping phlox (Phlox subulata)

  Forms similar flowering mats, but has needle-like leaves and flatter flowers with visibly notched petal tips; flowers may be pink, purple, white or bluish.

• Hardy plumbago (Ceratostigma plumbaginoides)

  Has broader leaves, flowers mainly in late summer and autumn, and loses its foliage in winter, often after turning red.

• Purple gromwell (Buglossoides purpurocaerulea)

  Produces more upright leafy shoots, has flowers that change from purple to blue, and spreads by rooting runners; it usually grows in partial shade rather than an open rock garden.

The species name diffusa means spreading, referring to the plant's low, outward-growing habit.

Propagation. Take semi-ripe cuttings from nonflowering shoots in summer and root them in a gritty propagation mix. Layering low stems is another option; seed-grown plants may not match named cultivars.

Accepted botanical name

Glandora diffusa

Native range

Spain.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.