Saxifraga 'Superba' (_callosa_ subsp. _callosa_ var. _australis_) (8)

Synonyms

Saxifraga callosa subsp. callosa var. australis 'Superba'
Saxifraga lingulata 'Superba'

Alpine Rockery

A mat-forming, evergreen perennial with rosettes of silvery-green leaves between 2.5 and 4.5cm long; the lower leaves being markedly longer than upper ones. Panicles of white flowers are borne in spring and early summer on flower stems up to 17cm tall

Position

Full sun, Partial shade

Soil Types

Chalk, Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 2–5 years
Max Spread: 0.1-0.5 metres
Max Height: 0.1-0.5 metres

Growing Conditions

Chalk Loam Sand

Moisture: Well–drained
pH: Alkaline or Neutral

Position

Full sun Partial shade

Aspect: South–facing or East–facing
Exposure: Exposed
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H5

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Saxifragaceae
Native to GB/Ireland: No
Foliage: Evergreen
Habit: Clump forming
Genus: Saxifraga can be annuals, biennials, evergreen or herbaceous perennials, mostly mat-forming in habit, with simple or palmately lobed leaves and starry or rounded flowers which may be solitary of in panicles or cymes
Name Status: Accepted
Horticultural Group

Horticultural Classification Codes

Horticultural Classification Codes are often given to genera which have a large number of species or cultivars. They are used to categorise cultivated plants based on specific, shared characteristics such as shape, colour, size or flowering time, and can be displayed as letters or numbers

For example:
Dahlia ‘Sunset Kate (Sin) = Single flower
Rosa ‘Marigold’ (HT) = Hybrid Tea: Ligulatae section saxifrages are evergreen perennials forming monocarpic rosettes, usually clustered, of narrowly strap-shaped or oblong, lime-encrusted leaves, with sprays of small white, pale yellow or pink flowers in late spring or early summer

How to Grow

Cultivation

Grow in moderately fertile, very well-drained, neutral to alkaline soil; keep roots moist. Tolerant of full sun in cool areas but protect from leaf scorch in warm areas

Propagation

Propagate by detaching rosettes and rooting as cuttings in late spring or early summer

Suggested planting locations and garden types

Patio and container plants
Rock garden
Gravel garden

Pruning

No pruning required

Pests

May be susceptible to aphids, slugs, vine weevil and glasshouse red spider mite

Diseases

Generally disease-free