Rock Spiraea
Petrophytumcaespitosum

Category
Alpines and Rock Gardens
Groundcovers
Perennials

Water Requirements
Drought-tolerant; suitable for xeriscaping

Sun Exposure
Full Sun

Foliage
Evergreen
Provides Winter Interest

Foliage Color

Height
under 6 in. (15 cm)

Spacing
4-6 ft. (1.2-1.8 m)

Hardiness
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)

Where to Grow

Danger
N/A

Bloom Color
White/Near White
Cream/Tan

Bloom Characteristics

Bloom Size

Bloom Time
Late Summer/Early Fall
Mid Fall

Other details

Soil pH requirements
5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)
7.9 to 8.5 (alkaline)

Patent Information

Propagation Methods
By dividing the rootball
From seed; direct sow outdoors in fall
From seed; stratify if sowing indoors

Seed Collecting
Allow seedheads to dry on plants; remove and collect seeds