Rimu trees restored to Kāpiti

Native bush restoration projects on the Kāpiti Coast have received a boost from the planting of 150 rimu trees that were grown from local seed.

Kāpiti Coast District Council Programme Manager Biodiversity Rob Cross says being able to plant this native forest species is a first for the District.

“Rimu can be planted once other hardier species are mature enough to provide shelter. Many of our restoration sites have reached that milestone and we’re rapt to have a decent number of locally sourced rimu available for the first time.”

The plants came from seed collected in the Maungakotukutuku Valley, and it took four years for the rimu to grow big enough to plant.

“Rimu seed is hard to collect and slow to propagate and grow, which is why we’ve never had a supply of locally sourced plants before,” said Rob.

Few rimu survived the forest clearances and logging of the 19th and 20th centuries. Large-scale logging of rimu continued in the Tararua foothills until the 1970s. By that time most of the big accessible trees suitable for milling were gone.

“Like other forest giants such as totara, matai and kahikatea, naturally occurring rimu vanished from much of its former range,” said Rob. “Planting these magnificent, long-lasting trees is important to restoring healthy native forests for wildlife and people to enjoy.”

The rimu were planted by Council staff and community volunteers in small numbers at sites where they would have occurred naturally, including Kaitawa Reserve in Paraparaumu, and along the Waikanae and Ōtaki river corridors.

“Outside the Tararua Ranges and foothills rimu had a limited range, only growing in places that were just right for the species,” said Rob. “We’re trying to mimic that natural distribution.”

Successfully propagating rimu is an outcome of a Council biodiversity project started eight years ago, which was designed to increase the range and supply of ecologically sourced native plants - plants grown from seed that has been collected from wild local plant populations.

“Eco-sourced plants perform better through being adapted to local conditions, and also help preserve the distinct local identity of local native plants. The supply of these kinds of plants used to be limited and unreliable. By coordinating seed collection we’ve been able to use 18,000 eco-source native plants for Council restoration planting projects this year.”

As well as rimu, formerly unobtainable or rare species such as sand daphne, black and white maire, twiggy tree daisy, sand coprosma and narrow leafed lacebark are now available for restoration planting projects.

“We’ve been able to dramatically increase the range of plant species we can use, which is key to restoring healthy and resilient native plant communities that support a multitude of wildlife.”

Special delivery -

Kāpiti Coast District Council Programme Manager Biodiversity Rob Cross with a tray of rimu seedings for restoration planting.

Kāpiti Ecological Restoration Maintenance Trust contractor Brent Buckler plants a rimu tree on the Waikanae River corridor.