TNZ Best Practice

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TNZ Best Practice


We take pride in ensuring our products are supplied to you in the very best condition possible.

The steps we take to ensure this include: 

  • TNZ Grow incorporates NIASA/FMS (industry body best practice) scheme standards to ensure you receive the highest possible quality products.
  • The customer is required to approve all custom potting mix blends before we commence manufacturing.  This is particularly the case where the customer requires blends which go against our or any fertiliser supplier’s recommendations.
  • Chemical and physical properties of all custom mixes are tested on site before dispatch.
  • Electronic print-outs are kept from every custom blend which detail the fertiliser rates which have been applied. These are cross checked before each batch is released to the customer.
  • Compost and chemically aged bark temperatures are monitored throughout the composting process to ensure that both products are fully stabilised before being released for sale.


  • Every batch of chemically composted bark is tested by Hills laboratory to confirm maturity.
  • Additives such as coir which have the potential to cause salinity issues are only purchased from reputable sources with full documentation of processing and handling.
  • All operators tasked with mixing custom blends are fully trained on site.
  • Any equipment used for blending mixes is periodically washed down and disinfected to prevent the risk of cross contamination.
  • Most custom blends are grown out on site with a range of different crops to ensure no deficiencies or toxicities are present.
  • The majority of our custom mixes are either baled to prevent cross contamination or dispatched using in-house transport.

Product Care


TNZ Grow cannot be responsible for contamination of its products once they have been delivered to its customer and/or end user.  Customers should take particular care in the following instances: 

When transporting media to ensure: 

  • Truck has been adequately washed down
  • Truck has been covered/ tarped correctly
  • Baled product wrapping is not breached by forklift or other source of mechanical damage


  • Holding bins have been cleaned down sufficiently
  • Holding bins are made of suitable materials
  • Weed spraying or similar chemical activity does not occur near bins
  • Contaminated run off does not enter bins and is absorbed by the media
  • Media is protected from windblown contaminants
  • Media is protected from environmental factors eg extreme heat


  • Pots or trays are not exposed to undesirable chemicals
  • Media is not heavily compacted in trays during potting process – stunting sensitive crops

Nursery Environment

  • Plants are not exposed to extreme environmental factors: temperature, light, water, humidity etc
  • There is a spray program to prevent pest & disease issues
  • Proper clean down of growing areas and equipment
  • No exposure to undesirable chemicals eg weed killer

TNZ Grow also recommends that its customers and/or end users undertake the following risk mitigation steps to ensure that the media remains in the very best condition and ensures optimal results: 

  • Check baled products for breached packaging
  • Ensure operators handling bales are sufficiently trained
  • Ensure bins that media will be stored in are cleaned thoroughly and non-porous
  • If bins are in open areas consider covering them to prevent contamination
  • Ensure that no unwanted chemical activities eg spraying occur near the media
  • Check pot filling procedures to ensure the media is not unnecessarily compacted
  • Growing environment should be suitable for the crops being produced to ensure plants are not placed under undue stress
  • A thorough spray or IPM program should be in place to protect crops from insect damage
  • Any changes made to the media recipe should be trialled in a controlled environment to ensure no adverse effects are seen and that the customer is happy with performance before adopting the changes.
  • Best practice would see customers monitoring their media properties with basic onsite testing so that any undesirable changes are discovered quickly and corrective action can begin immediately.