south of Brisbane, reports 3/3 in meeting selection cri-
teria for two species that are endemic to rainforests of
eastern Australia: blunt-leaved tulip (Harpullia hillii)—
from dry rainforest—and firewheel tree (Stenocarpus
sinuatus)—from a variety of rainforest types.
In talks at Treenet events, Tim Johnson
highlights the long-term successes he's observed in
South Australia of street trees like wilga, also known
as Australian willow (Geijera parviflora). Endemic
to eastern inland Australia, wilga has made its way
to the streets of California, Florida, and Texas in the
U.S. where it lends its pest-free nature, ability to cast
generous shade, and tolerance of dry conditions.
Johnson has also witnessed the success of street
trees like Zelkova serrata and Acer buergerianum,
familiar to those readers living in temperate climates.
When he brings up crow's ash (Flindersia australis),
endemic to northeastern Australia, Johnson says with
affection, "Flindersia. Say no more." Ongoing South
Australia street tree trials include narrow-leaved pep-
permint box (Eucalyptus cajuputea)—"It's tough as
bags," Johnson says—mulga (Acacia aneura), a small
tree that Johnson has been recommending for growing
under utility wires since the 1990s, and sugarwood
(Myoporum platycarpum), a small, tough evergreen tree
endemic to much of the southern half of Australia.
In one shared talk Johnson did with Ruby Wolfe, City
Greening Lead at the City of Hobart, Tasmania, Wolfe got
into the very interesting particulars of urban forestry in
the second driest capital city in Australia. She says that
because Tasmania is an island, strict quarantine protocols
preclude importing plant material, so her department
started their own city nursery. Another challenge is that
because Hobart runs cold—for now—compared to the
rest of Australia, "People aren't so interested in shade >>
Based on decades of observation in South Australia, Tim Johnson
is a proponent of the pest-free, drought-tolerant wilga (Geijera
parviflora) for street and park use. Photo from Selectree
Foliage and flowers of wilga. Photo by
Peter Woodard, Public Domain
38 CityTREES
