Scientific: Eucalyptus coolabah (closely related to E. microtheca)
Common: coolabah
Family: Myrtaceae
Origin: Widely distributed across Australia in riparian zones

Pronounciation: Ewe-ka-LIP-tus COO-la-bah

Hardiness zones:
Sunset 5, 6, 8-24
USDA 8-11 (arid and semi arid regions are best)

Landscape Use: Moderate sized tree for many Phoenix landscape uses from garden to street tree

Form & Character: Variably upright and spreading, often irregular in its spread, rugged.

Growth Habit: Woody, evergreen perennial tree, moderate growth rate to 30 to 40 feet in height with usually greater spread.

Foliage/texture: Juvenile leaves are disjunctly lanceolate to broadly lanceolate, dull grey-green to glaucous in color. Adult leaves are disjunct, narrowly lanceolate, 3 to 6 inches long to 1 inch wide, a dull grey-green in color. Coolabah's bark on its trunk is persistent, dark grey, thick, and furrowed; medium texture.

Flowers & fruits: Small, creamy flowers followed by small seed capsules.

Seasonal color: Glacous blue green foliage all year creates feeling of space. Clusters of white flowers in the summer.

Temperature: Very Hardy to 6 to 10oF and tolerant of high temperatures associated with parking lot exposures

Light: Full sun

Soil: Very tolerant

Watering: Infrequent deep summer irrigation

Pruning: Prune and stake all eucalyptus vigorously when young, especially collabah as its habit is prone to be spreading, irregular and not strongly upright.

Propagation: Seed, difficult, requires a flooding pre-treatment for rapid germiniation.

Disease and pests: None

Additional comments: E. coolabah is somewhat similar in apearance to E. microtheca and for the most part in the Phoenix area they are functional equivalents. The main external difference is that E. coolabah has more smooth bark.