Rosa californica (S)

Roses

Rare in cultivation, a large species rose native to W. USA, about 2.5m tall, with prickly, strong, thick stems and mid-green leaves composed of leaflets. Clusters of slightly scented, single pink blooms to 3cm across, once-flowering in midsummer followed by rounded red fruits (hips)

Position

Full sun

Soil Types

Chalk, Clay, Loam, Sand

Max Height

1.5-2.5 metres

Max Spread

1-1.5 metres

Size

Time to Maturity: 2–5 years
Max Spread: 1-1.5 metres
Max Height: 1.5-2.5 metres

Growing Conditions

Chalk Clay Loam Sand

Moisture: Moist but well–drained or Well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun

Aspect: East–facing or South–facing or West–facing
Exposure: Exposed or Sheltered
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

Fragrance Flower

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Rosaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Bushy
Potentially harmful: Fruit are ornamental - not to be eaten. Wear gloves and other protective equipment when handling. Pets: Fruit are ornamental - not to be eaten - see the HTA guide to potentially harmful plants for further information and useful contact numbers
Genus: Rosa can be deciduous or semi-evergreen shrubs or scrambling climbers, with usually thorny stems bearing compound pinnate leaves and solitary or clustered flowers. Flowers may be followed by showy red or purple fruits in some varieties.
Name Status: Correct
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: Shrub roses are large shrubs with usually thorny stems bearing large leaves and fragrant, single to double flowers in clusters in summer, and usually also in autumn
Plant Range: USA (CA, OR), Mexico

How to Grow

Cultivation

Grow in fertile, humus-rich, moist but well-drained soil in full sun. Mulch with well-rotted organic matter in late winter or early spring, and for best flowering apply a general rose or shrub fertiliser in early spring and again in early summer. Suited to wild gardens. See rose cultivation

Propagation

Propagate by softwood cuttings in early to mid spring, hardwood cuttings in late summer to autumn or by chip budding in summer; propagate by seed; species roses can be propagated by seed but need stratification and germination may take two seasons

Suggested planting locations and garden types

Cottage and informal garden
Wildlife gardens
Hedging and screens
Wall side borders

Position

Soil Types

Max Height

Max Spread

Size

Growing Conditions

Position

Colour & Scent

Botanical Details

How to Grow

Cultivation

Propagation

Suggested planting locations and garden types

Pruning

Pests

Diseases