Scientific name: Metrosideros excelsa
Not native to Wellington
Pohutukawa’s red flowers might look jolly along our streets and gardens, but in many places around New Zealand our grand pohutukawa is becoming a serious weed.
- creates heavy shade where, otherwise, high light levels would occur.
- has bark and leaves that produce tannins, a chemical that suppresses other plants from growing and leaches the soil.
- is fast growing, competing with slow growing coastal forest trees, shrubs, grasses and herbs.
- has wind-dispersed seed which can travel several kilometres, colonising open and disturbed sites, including coastal cliffs.
- forms unwanted hybrids with other species via tui and other nectar feeders. These pose a significant long-term threat to the already rare and endangered northern rata.
Pohutukawa’s natural restriction is northern New Zealand and the Auckland region, where plants occupying the same habitat have adapted to compete with it. But in areas such as Matiu/Somes Island, Kapiti Island and the Wellington coast, pohutukawa is altering our coastal forest ecosystems.
Threat to northern rata
Northern rata, an equally attractive tree local to Wellington, has been reduced to small populations and individuals, primarily as a consequence of settlers and possums. In places where northern rata should be making a comeback hybrids and varieties are now showing up instead. In some places around Wellington, and also smaller islands, such as Matiu/Somes Island, they are now being destroyed.
Please also avoid pohutukawa from Tahiti and the Kermadec Islands.
Pohutukawa is also a serious invasive weed in South Africa, Australia and California.