Coco peat/Coir fibre

Importing Coco Peat Products - updated 30 September 2008

Questions regarding further imports of coco peat and coir products should be directed to Michele Dickson, Plant Imports, MAFBNZ, ph 04 894 0462 or Shane Olsen, Plant Imports, MAFBNZ, ph 04 894 0460.  For futher information on registering a glasshouse with MAFBNZ, contact Elen Rogers, ph 09 909 8531.

Suspected new-to-New Zealand weeds

Current situation

  • Coco peat (a type of coir/coconut fibre) has been imported into New Zealand for around 20 years, but imports have increased markedly in the past five years. Coco peat is used widely in the nursery and horticulture industries as a growing medium for plants.
  • New-to-New Zealand weeds associated with imported coco peat were reported to MAFBNZ on February 15th.
  • Since then a number of nurseries around New Zealand have been visited and new-to-New Zealand weeds have been found at several sites. The nurseries involved have undertaken weed control on their sites, including weed removal and the application of a pre-emergence herbicide.
  • 25 new-to-New Zealand weed species have been detected in imported coco peat to date.
  • MAFBNZ has conducted risk assessments to determine the likelihood of establishment and potential impacts of the weeds. The risk assessments conclude that the weeds pose a low risk to New Zealand, primarily because they are not well suited to New Zealand’s temperate climate.
  • The response to these weeds has now been stood down and no further action will be taken.

Risk management options for suspect weed contaminated coco peat/coir fibre

Recommendations for minimising risk

1. Potted plants

a. Hand weeding

Please hand-remove as many weeds as practicable from the at-risk-pots. The weeds removed should be contained within a central location and then destroyed. Suggested methods of destruction include:

  • incineration,
  • sterilisation (heat/ steam),
  • deep burial, which includes placement in council or other landfill rubbish collections.

b. Pre-emergence herbicide treatment.

Hand weeding must be completed first. Please use any pre-emergence herbicide product and application rate you consider appropriate for your potted plant types, to treat all pots containing the risk coco peat potting mix.

1. Treatment of remaining potentially contaminated potting mixes.

Options: In order of preference:

Please use any of the below that you consider would be most appropriate for your remaining risk potting mix.

  • Deep burial of potting mix.
  • Steam sterilization of potting mix.
  • Hot composting - with the emphasis on "hot", ideally with a minimum core temperature of 70°C. Hot composting can be of short duration (1-2 months).
  • Composting at cooler temperatures of longer duration. Cover mix with tarpaulin for a minimum of 12 months. Leave for 4 - 6 weeks after tarpaulin removal before use.
  • Continued use of potting mixes and application of a pre-emergence herbicide before distribution, however this provides a lower level of control than the above options.

Page last updated: 30 September 2008