Plastic pot alternatives
By Patrick Regnault
Over the last few decades, the industry has made great strides with water and fertiliser use. Pots and the use of plastic is an area where progress can be made. Some nurseries will take back the pots to sterilise them before reuse, and others will recycle them as part of a scheme.
Some councils resell them in their tip shops. Still, many pots sold to landscape companies end up in landfill, where long-term risks of soil and groundwater contamination from ultraviolet light stabilisers and additives used in plastic products are unknown (Hopewell et al., 2009; Teuten et al., 2009).
The well-known 3Rs, Reduce – Reuse – Recycle, have allowed us to minimise our damaging footprint and make very large savings. The first one is the most important.
Reducing water and fertiliser waste has greatly benefited the financial bottom line of production nurseries. In landscaping, reducing waste through careful resource management and scheduling has allowed big savings and is becoming a selling point for clients.
Reusing pots can be done, and according to an Australian nursery paper, Waste in the Nursery Industry* by David Hunt, savings can be made by using a steam generator and cargo container. The savings would depend on the age of the machine and how often it is used.
Recycling black plastic pots cannot be recycled in most cases as sorting machines cannot detect the colour black. This does not mean that nothing is done to remedy this deficiency. A new scheme called PP5 has started setting up collection points for plastic plant pots and plant labels at the nurseries that sell them. If you go to https://www.pp5.com.au/, you will find the place near you where you can place your used PP5 pots, which will then be recycled and made into new nursery products by Norwood printers and Garden City Plastics.
Alternatives are available. Biodegradable paper Biopots, for instance, are comparable to 75mm forestry tubes and housed in 32-cell reusable air trays. They can be planted straight into the ground as the Biopot will biodegrade, reducing transplant shock. These are very useful for mass planting native grasses for large landscape jobs. Many avenues are being explored to find alternatives to plastic containers. Plantable or compostable, biodegradable containers are marketable, and are a path to improve the sustainability of current production systems. They can be made of peat, coco coir, cardboard, bamboo, wood fibres, cow manure and natural fibres, rice hulls, corn and wheat base, and bioplastic.
Biodegradation of plantable pots varies greatly depending on soil pH, bacterial activity, moisture levels, and climate. Compostable pots are not for your backyard compost heap but for industrial facilities where the conditions will be more suited to their degradation.
Bioplastics are lightweight, structurally stable, rigid, and resistant to decay. They are most like traditional plastic pots, which allows them to be fabricated on the same machines as other plastic pots. They are suitable for short and long-term crops. They can be composted anaerobically in landfills. Some bioplastics have a petrochemical-based polymer blend.
Most alternative pots are small and suitable for forestry, bush regeneration, annuals, and vegetables. They can help reduce the plastic footprint. Recycled plastics are a suitable alternative, giving prolonged use to a near-indestructible material.
Plastic pots will not disappear for quite a while as they have many advantages that have yet to be paralleled. More research needs to be done to seek viable alternatives, mostly for larger containers. In the meantime, as landscapers and horticulturists, we must do our best to seek alternatives, return our PP5 pots to be recycled at the nearest facility, and find plant design solutions.
Plastic creates problems in the environment, our bodies, and even our brains. It is a great product, but the side effects of microplastics are only now being made clear to the public. Research funding could help Australia be at the forefront of innovation, and perhaps finding excellent alternatives to petrochemicals may open new fields in engineering, construction and much more.
Patrick Regnault FAIH RH0062
Interactive Landscapes
E: patrickregnault@hotmail.com