Common name: Bottlebrush (‘Harkness’ & ‘Kings Park Special’ )
Callistemon ‘Harkness’ is one of the well-known Bottlebrushes that has been an excellent street tree for many years. Also known as ‘Gawler Hybrid’, this plant has proved valuable throughout Victoria and South Australia. The smaller-growing ‘King’s Park Special’ is also well-known for its ability to grow in difficult locations while forming a compact, showy plant.
As hybrids between C. citrinus and C. viminalis, ‘Harkness’ and ‘King’s Park Special’ show intermediate qualities of both. ‘Harkness’ is slightly weeping, has long, stiff, grey-green leaves, and has deeply-fissured, blackish-grey bark. The flowers are exceptional: crimson-red bottlebrushes to 200mm long, borne in late spring and early summer. These flowers can last for up to 6 weeks, and leave few-to-no fruits behind.
‘King’s Park Special’ grows to 4m, has more upright growth, and also has profuse red bottlebrush flowers. This cultivar is ideal where the space is very limited on a narrow nature strip.
These cultivars will thrive in both the cooler areas of Victoria as well as the hot towns in the Mallee. Although they grow best with some summer irrigation, plantings throughout South Australia survive well with no additional irrigation post-establishment.
Callistemon ‘Harkness’ & ‘King’s Park Special’ also seem to grow well in a variety of soils, from sandy, skeletal soils, to heavy, clay-filled soils. They grow well on most nature strips, and will also grow reasonably well in planter boxes, or restricted planting areas cut out of bitumen.
As a tree growing only to 6m tall, Callistemon ‘Harkness’ is another valuable plant for restricted sites. This growth form, combined with excellent flowering and tolerance to difficult sites makes ‘Harkness’ a necessary plant for streetscapes. When even less planting space is available, ‘King’s Park Special’ is an excellent, red-flowering Bottlebrush.
Typical mature height: to 6m (‘Harkness’)
Useful in: streetscapes, reserves & parks
Sites for best growth: many site conditions