Rhamnus: The Quiet Danger in Howick

One of the worst weeds in the Howick area is relatively unknown. Unlike moth plant, which is known for its large green pods, cable-like vines, spearhead-shaped leaves, and sticky white sap, Rhamnus is by appearance an inconspicuous shrub.

Also known as evergreen buckthorn, Rhamnus is a Mediterranean shrub that can grow to fifteen metres tall, although it is more commonly seen growing at heights of about two to three metres. It is sometimes mistaken for the native tree species Coprosma robusta (Karamu). While both plants display glossy, deep green leaves, Rhamnus leaves are typically smaller and have serrated edges. Shoots have purplish, hairy stems, and larger shrubs have reddish wood. Both plants have red, bird-dispersed berries, although Rhamnus berries will only appear in December to January. 

Rhamnus is primarily found in (although not limited to) coastal sites like Bucklands Beach and Eastern Beach. Rhamnus exists at a relatively low density in the Howick Ward, although the key issue is its potential to spread and smother coastal habitats. As a plant that is tolerant to salt, wind, frost, heat, grazing, deep shade, and poor soils, Rhamnus is a prime candidate for invading the coastal Pohutukawa forests that Aucklanders know and love.

If you see Rhamnus, please contact Pest Free Howick so that we can remove it! Rhamnus is commonly found in unlikely locations. Don’t just look for it in parks and reserves, often it will exist as neatly trimmed hedges in backyard gardens!

If you would like to remove Rhamnus yourself, please refer to the weedbusters website: https://www.weedbusters.org.nz/what-are-weeds/weed-list/evergreen-buckthorn/