Auckland's natural environment

Coastal planting

Waiheke Island

Native coastal vegetation fulfils several important functions, including:

• good cover to protect coastal soil and sand from erosion by wind and water
• protecting the natural character of the coastal environment
• providing an important buffer, screening buildings and providing habitat for native birds and animals.

Planning

• Carefully check the proposed planting site for signs of early human occupation (e.g. midden, pa defences). Permission is required from the New Zealand Historic Places Trust before disturbing any archaeological sites, e.g. planting into midden. Contact the ARC and talk to an archaeologist if more information is needed
• Prepare the site before planting. Remove existing weeds. It may be appropriate to retain some exotic species in the short term if they are helping to control erosion or if they will shelter, but not smother, young native plants
• Ensure that your coastal planting and existing natural areas are adequately fenced to protect them from stock and people. Avoid over-grazing, stock treading or wallowing, which will destabilise vegetation and may erode farm land. Encourage natural regeneration by keeping stock out of natural areas such as estuaries and mangroves. Time any planting for the ‘planting season' from April to June to avoid drought. This encourages root systems to become well established before the soil dries out in summer.

What to plant

For a general list of native coastal species to plant in the Auckland region check out our Coastal Planting Guide 1 - general. For coastal plants for specific coastal zones, refer to Coastal Planting Guides 2-6.

Planting tips

• Choose a mixture of canopy and shrub layer plants with higher numbers of colonising species to establish shelter. Introduce other species later to enhance overall plant diversity
• To aid the survival of plants in the coastal zone, use reasonably large size potted stock in either PB3 or PB5 planter bags, or budget for replacement planting
• Soak the plant thoroughly before planting. Plant with the root ball just below the soil surface (with the exception of fore dune plants) and ensure plants are well watered at the time of planting and as required thereafter
• Spacing of plants will differ depending on growth form. For example, sand binding species and sedges need to be planted 0.5m apart to encourage vegetation cover, while trees and shrubs will only need to be planted at 1 -1.5m apart. Larger trees such as pohutukawa need to be planted more than 5m apart. Set plants out in groups and plant closely to each other to provide sheltered environments. Some species are more suited to being planted in open areas to establish nurse crops for other native species
• If your budget allows, incorporate a 12-month slow release fertiliser (such as ‘grow tabs') into the hole when planting to give plants a boost
• Consider erecting some form of temporary shelter to reduce plant damage from salt-laden wind. Temporary shelters made from shade cloth are useful but expensive, and will require maintenance. Take advantage of shelter provided by existing plants.

Ongoing management

Planting requires an ongoing commitment to:

• weed management until the plants have successfully established. Remove weeds from around plants for up to two years following planting or until the native plants are tall enough to eventually crowd them out. In some environments where vegetation is naturally sparse, ongoing weed control will be required
• ongoing animal pest management may be required as coastal conditions often provide an ideal habitat for rabbits and possums, which can cause considerable damage to natural areas and new plantings by browsing and burrowing. Possums can be a major pest in the coastal environment, damaging palatable species such as pohutukawa
• replanting. Coastal vegetation will not provide structural stability to an eroding coastline. However it will help manage erosion by providing some surface stability through vegetation cover and soil binding roots. It may be necessary to maintain your coastal planting by replanting areas that have been damaged by slips and harsh coastal conditions.

To limit the adverse effects of pedestrians to and along the coast ensure that appropriate access ways are provided and are clearly identified. It may be necessary to erect some temporary fencing until plants are well established.

You may be eligible for a small-scale initiatives funding for any restoration or planting you under take.