Kudos to the arborist in Tauranga who decided to plant Hymenosporum flavum in Grey Street. The trees are really coming into their own and look magnificent when in flower.
I’ve heard the glossy-leafed tree referred to as both NSW frangipani and Queensland frangipani, while in Australia they seem to refer to it only as “native frangipani” as it grows well in most parts of the country. Oddly, my two reference books (admittedly from book fairs) about Australian plants don’t mention it.
The trees grow fairly fast – depending on the climate from 10m to 25m at maturity – but don’t tend to be long-lived, although there is one in California that was planted in 1904 (see below). We removed one from the garden that was no more than 30 years old but showing signs of being at its end. The tree’s branches can be brittle in strong winds.
The Australian Native Plants website notes that the tree is closely related to Pittosporum and native to the coastal forests of eastern Australia from the Hunter River in New South Wales to Atherton in Queensland and extending to New Guinea. The tree naturally keeps to a tidy, if rough, pyramidal shape.
According to the San Marcos Growers website, the tree (with the common name sweetshade in the US) is believed to have been introduced to California in 1900 by renowned horticulturalist Dr Francesco Franceschi with many large specimens still in the Santa Barbara area, including what is listed as the largest specimen (planted in 1904) on the California Big Tree Registry. (If you like reading about ‘characters’ do click on the good doctor’s name.)
Hymenosporum flavum is included in the Tasmanian Fire Service’s list of low-flammability plants. Read more about Fire Retardant Garden Plants.
There is also a shrub form known as Gold Nugget, which grows to about a metre high and wide, and which responds well to pruning. However, this is the 2006 NZ Gardener magazine response to a question about why a Gold Nugget wasn’t flowering: “[It’s] … been a bit of a disappointment for some gardeners. Although it can grow well and form a lovely compact, bushy shrub, some individual plants just don’t seem to flower well. Sometimes one will flower every year while another plant in the same conditions won’t flower at all and there’s no obvious reason why.”
Hymenosporum flavum is no relation to the tropical frangipani, Plumeria.