A citizen science project that aims to boost biodiversity by bringing back native mistletoe into urban Christchurch.

The project

Native green mistletoe/pirita has all but disappeared from urban Christchurch. Native birds, needed to spread mistletoe, are rarely found in the city which means mistletoe isn't returning naturally.

For the past two years, our goal has been to work with the citizens of Christchurch to establish 500 mistletoe plants and in doing so, boost biodiversity by attracting native birds and insects back to our urban environment.

After seeding their mistletoe, volunteers have been keeping us up to date with their progress via online surveys. From these surveys we are able to learn more about how mistletoe are established and how many have germinated.

Timeline

In 2016, the project was started as student research, funded by the Friends of the Christchurch Botanic Gardens and the University of Canterbury. Mistletoe was seeded throughout the Botanic Gardens, and 33 plants have established.

In 2017, mistletoe was seeded throughout 300 volunteer's backyards. We know 350 plants germinated from these seeds.

In 2018, mistletoe was again seeded throughout another 300 odd backyards, and we now have a total of 493 germinated mistletoe. 

More about mistletoe

Green mistletoe establishment

Native mistletoe is hemi-parasitic. This means they need to take nutrients and water from another plant (their host) but they still photosynthesise and produce flowers and fruit.

There are nine different varieties of native mistletoe although one has been extinct since 1954. For this project, we are focusing on one of the green mistletoe, Ileostylus micranthus because it is capable of growing on over 200 host trees and shrubs. It is currently found on the Port Hills and Banks Peninsula.

Ileostylus grows on shrubs and trees, forming an evergreen ball of lush leaves – it can grow up to two metres but it is more commonly around one metre. This mistletoe produces small green flowers in summer and bright yellow fruit through autumn and winter. During winter when your deciduous trees lose their leaves, the mistletoe will brighten your garden.

Green mistletoe is also known to attract native birds, and insect pollinators such as bees.

Useful resources

Common host species

Green mistletoe/pirita (Ileostylus micranthus) is known to grow on over 200 types of trees, both native and exotic.

From the 2017 and 2018 sowings, we found higher germination rates on the hosts below:

Common native species Common exotic species
  • Coprosma
  • Kōwhai
  • Hoheria
  • Olearia
  • Mānuka
  • Wineberry
  • Pittosporum
  • Veronica (hebes)
  • Oak
  • Tree lucerne
  • Lemon
  • Ash
  • Maple

Over the two years, oak and coprosma had the highest germination rates at 25% and 19%, respectively.