kauri care guide About this booklet This booklet is for landowners, managers and occupiers with kauri on their land. It explains the ecology of kauri, common diseases and gives advice about care and propagation. This booklet has three main sections: 1. Kauri ecology We describe the kauri family, how kauri grow and reproduce, and diseases that affect these trees. 2. How to care for your kauri We give advice on how to reduce stress and care for your kauri. 3. How to grow kauri We describe how to gather seed, propagate and plant out kauri. A glossary of terms used and list of further reading is also included. Acknowledgements Compiled by Stacey Hill, Biosecurity, Auckland Council. Content provided by Auckland Council: Nick Waipara, Plant Pathologist, Biosecurity; Amanda Peart, Communications Advisor, Biosecurity; Brendan Mackie, Horticulturist/ Ranger; Damon Keen, Creative Direction Advisor; Auckland Council Natural Heritage Team; Auckland Council Biosecurity Team. Thanks also to: Ian Barton, Forestry and Environmental Consultant; Ian Horner, Plant Pathologist, Plant and Food Research and John Hogan, Three Streams Reserve. ISBN No: 978-1-98-857134-8 (print) ISBN No: 978-1-98-857133-1 (online) Disclaimer While every effort has been made to ensure the information in this publication is accurate, the Kauri Dieback Programme does not accept any responsibility or liability for error of fact, omission, interpretation or opinion that may be present, nor for the consequences of any decisions based on this information. Any view or opinion expressed does not necessarily represent the view of the Kauri Dieback Programme. KAURI DIEBACK | 0800 NZ KAURI (695 2874) | www.kauridieback.co.nz Contents Protecting kauri 2 Kauri ecology 3 The kauri family 3 Part of New Zealand history 4 Cultural significance of kauri 4 Early European influence 4 Distribution of kauri 5 Reproduction 6 How old is my kauri? 8 Bark 10 Gum 10 Roots 11 Kauri diseases 12 Kauri dieback disease 12 Other diseases 13 Insect and animal pests 14 How to care for your kauri 15 “Keep off the feet” 15 Mulch 16 Soil nutrients 18 Water 18 Provide some company… 19 ….but don’t crowd. 19 Pruning 20 More tips/general care 20 How to grow kauri 21 Gathering seed 21 Germination 21 Planting out and site preparation 22 Glossary 24 References and further reading 25 Websites 26 Images 26 Notes 27 The creation myth 30 KAURI CARE GUIDE 1 Protecting kauri Kauri are under significant threat from Kauri can be saved if everyone plays their kauri dieback disease, caused by a part. This means working together to microscopic, soil-borne pathogen known stop it from spreading, through strong as Phytophthora agathidicida (or PA). biosecurity practices. The PA pathogen damages the tree’s root • Making sure when visiting areas system, reducing its ability to take water with kauri that footwear, tyres and and nutrients from the soil and transport equipment are cleaned of all soil and it throughout the plant. plant material before AND after your There is currently no cure for kauri visit. dieback, which kills most if not all the • Keeping stock out of kauri areas. kauri it infects. The disease is spread • Ensuring people visiting your through soil movement, including property have soil-free footwear and through human activity. This means that machinery. when planting trees, visiting forests or • Contacting the Kauri Dieback Hotline undertaking any activity around kauri, 0800 NZ KAURI (695 2874) if you think following good hygiene and biosecurity a kauri tree is showing symptoms of practices is critical. kauri dieback disease on your land. There is a strong focus is on containing For more information, visit: kauri dieback disease within its current kauridieback.co.nz locations and stopping its spread into healthy areas. 2 KAURI CARE GUIDE 1 Kauri ecology The kauri family The New Zealand kauri (Agathis australis) belongs to one of the world’s oldest families of conifers, the Araucariaceae family, comprising 21 tree species. Kauri is the largest of the Agathis genus, and is endemic to New Zealand. Many of these great forest giants were felled by early pioneers for their high quality timber. One of the largest kauri trees ever recorded was Kairaru of Tutamoe, with an estimated diameter of 6.4 metres and a height of 65 metres. Unfortunately, Kairaru was destroyed in a fire before 1900. The largest kauri alive today is Tāne Mahuta, found in Northland’s Waipoua Forest. It has a diameter of 4.6 metres and height of 52 metres, and is estimated to be Simulated comparison of Tāne between 1200 and 2000 years old. Mahuta (left) and Kairaru (right). KAURI ECOLOGY 3 Part of New Zealand history Cultural significance of kauri together and support numerous other living creatures, as do chiefs or leaders of Kauri are considered a taonga by many any culture and society. New Zealanders, particularly Māori, who see the health of kauri as a sign of When required, particular kauri were general wellbeing - hence their value felled and carved into waka (canoes) for cannot be understated. various purposes – sea-voyaging, fishing, trading and transporting war parties to Kauri play an important role in Māori name some. This latter type, waka taua culture, through cosmogeny and (war canoe) are commonly seen today on ceremony, for use as weapons, tools, ceremonial occasions. shelter and transport, and in many other aspects of everyday life. Many larger kauri Kauri gum had many valuable functions. are given names and revered as rangatira Gum was burnt as an insecticide for (chiefs) through their ability to bring kumara gardens, wrapped in flax for use as torches at night, and also as kāpia or ngaungau (chewing gum). Kauri resin was also burnt and mixed with fat and/or charcoal for tā moko (tatooing). Early European influence By the mid-1900s, early Europeans had developed a thriving timber and gum industry based on kauri. Large areas of kauri were felled for their timber, which was valued for its strength and ability to withstand seawater conditions, making it ideal for boat masts and hulls. Above all, kauri wood was knot-free, so was considered perfect for high-end furniture. Kauri gum was used in varnishes, paint, and linoleum and to create ornaments. Gum was largely collected from the ground, however, some was gathered by deliberately injuring or “bleeding” trees. Estimates of the extent of kauri forest before European settlement in Bushmen watching a large kauri fall, Dome Valley, 1952. 4 KAURI CARE GUIDE New Zealand are between 1 million and The site, soil and temperature determine 1.5 million hectares. This was reduced the type of forest that can naturally to an estimated 7000 hectares (0.5% of contain kauri. There is no “typical kauri original extent) by exploitation for timber forest”: kauri can exist as solitary trees or destruction by fire and clearance in in broad leaf dominant bush, or together the late 19th and early 20th century. An in dense stands. estimated 60,000 hectares of secondary Kauri require high levels of light to forest and scrubland contain some grow, but they can tolerate low soil stands of younger kauri regenerating nutrient levels. Kauri seedlings are often after this harvest. suppressed under dense canopies of faster growing species in fertile soils. Distribution of kauri Consequently, they are often restricted to less fertile soils on ridges, or can Naturally occurring kauri are found establish themselves en masse after a throughout the warmer regions of the large disturbance such as a fire. upper North Island, above the latitude of 38°S (north of Kawhia/Hamilton/ In a forest environment, mature kauri Tauranga). emerge above the canopy of other native trees. The lower forest can contain a This means if you’re in native bush in the variety of other native tree species, Northland, Auckland, Waikato or Bay of including tōtara, tānekaha, taraire, tawa, Plenty regions, then you’re likely to find miro and rewarewa growing alongside kauri. juvenile kauri. At the shrub level, a range of plant species can be found, including tree ferns, nikau palms, lancewood, hangehange and mingimingi. Kauri grass (a species of Astelia) is commonly found covering the ground below kauri. A range of orchids and epiphytic plants are also often found growing amongst the branches of mature trees. Coromandel Auckland Current distribution of kauri in New Zealand. KAURI ECOLOGY 5 Reproduction Kauri reproduce through cones, which cones. Seeds then develop over a two- are formed every year, starting on trees year period within female cones, with from 20–40 years of age. one seed attached to each scale of the Kauri trees have both female and male cone. cones. Up to 100 seeds can be released from Male cones release pollen which is mature cones, although on average only carried by the wind to fertilise the female half of these will typically survive. Rod-shaped male cones and ball-shaped Kauri seeds with wings. female kauri cones. Male cones appear develop pollen released Female develop open for seed develops shed cones pollination scales appear 6 KAURI CARE GUIDE Kauri seeds rely only on the wind to be dispersed and have a small wing which enables them to catch even light winds. A gentle breeze can carry seeds 100–150m from the parent tree, although distances of up to 1.5km have been recorded. Kauri seeds lose their viability over a few months and are easily damaged by the cold and wet. Seeds need to land on soil to germinate. A viable seed needs favourable conditions, including good light, moisture, warmth and easily accessible soil nutrients, which are generally not found under the parent tree. If the seed reaches suitable conditions, germination takes place within 10–20 days.