Growing Media

Growing Media

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Queensland Grow Me Instead Project

The Nursery & Garden Industry Queensland (NGIQ) has successfully applied for funding under the FederalGovernments “Caring for our Country – Landcare Open Grants” to develop a Grow Me Instead (GMI) program along the east coast. The $190 000 project will create GMI Guides for three specific Queensland environments including the Wet Tropics, Dry Tropics and the Sub-Tropics. NGIQ will employ a GMI Coordinator (Mr. Barry Naylor) to oversee the project from orchestrating GMI reference groups through to the communication and education of stakeholders on the final outcomes of the project.

 

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Grow Me Instead – Guides and Website

In previous articles I have mentioned that Grow Me Instead (GMI) Guides have been developed for all states and territories of Australia, apart from Queensland. The GMI Guide is a DL sized handbook that discusses the invasive plant issue, encourages effective disposal of unwanted invasive plant material and lists 30 invasive plants along with a range of superior plants that should be ‘grown instead’. The project has reached the stage where in each of the three bioregions the final 30 invasive plants and their alternatives have been agreed upon. While there is still considerable work to complete the guides the aim is to have the Queensland GMI guides available during October this year.

 

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Grow Me Instead teams up with Plant Smart

On Thursday 19 November, Nursery and Garden Industry Queensland launched the Dry Tropics Grow Me Instead guide and website in Rockhampton with support from the Plant Smart program. Like Grow Me Instead, the Plant Smart program is an educational program to promote the planting of appropriate plant species. It is a partnership with Greening Australia and Ergon Energy to educate on the planting of appropriate vegetation under and around powerlines.

https://www.ngiq.asn.au/wp-content/uploads/securepdfs/2-Grow-Me-Instead-Plant-Smart-2009-Barry-Naylor.pdf

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Grow Me Instead Invasive Plants – Who sets the agenda?

The Grow Me Instead project has tried to indentify 30 plants in each of three bioregions (Sub-Tropics, Dry Tropics and Wet Tropics) that are considered invasive and are still being produced and sold. The chosen plants come from lists that historically have been referred to as ‘Environmental Weeds’. Each local authority has a ‘hit list’ of plants that it deems undesirable, with the ultimate aim that the reduced demand will finally result in zero production. There are nursery owners who operate ‘on the fringes’ who will always be happy to grow something that is considered ‘marginal’ by a local authority. Ever the opportunist, they will produce some amazing plants; I have even heard of ‘mother of millions’ being for sale in a gold coast garden centre! That plant is actually declared by the state government, and selling it may incur a $30 000 fine! It pays to know who sets the agenda with weeds and invasive plants.

 

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Grow Me Instead

There have been some interesting discussions over the past month on why certain plant species are being nominated for the Grow Me Instead (GMI) program. The GMI program has been rolled out in all states and territories, with Queensland being the last state to have published GMI booklets. Within the program there are established protocols for determining whether a certain plant species should be included in the local GMI booklets. The subject plant must satisfy the following criteria to be considered as a GMI candidate;

 

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Grow Me Instead - Media Coverage

The Grow Me Instead project has generated a significant amount of free media coverage. There has been particular interest from WIN TV in Rockhampton and Townsville and Channel 7 in Mackay and Cairns. The TV coverage coupled with regular radio interviews and print articles indicate how highly regarded the Grow Me Instead initiative is. This should serve as encouragement to the broader industry to support the program and make the most of the opportunity to position your business as one that cares about the environment and offers non-invasive solutions.

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Grow Me Instead – The Opportunities

The Grow Me Instead (GMI) project has made significant progress during the past month. Three regional stakeholder committees have determined the 30 invasive species for each of the three Bioregions. In addition, there has been discussion and agreement on the plants that will be put forward as alternatives to the invasive species. In all cases there will be at least three superior plant selections put forward, in some cases up to five suggestions may be made. This is one of the greatest opportunities that the project presents; promotion of a range of superior plant selections.

 

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Grow Me Instead - Partnerships for the future

The Grow Me Instead project has been a wonderful opportunity for the Nursery and Garden Industry to put our environmental credibility on show. It is a real feather in our cap to take this proactive stance on invasive plants; showing government and the community we care about the environment and are prepared to take positive action to reduce the impact of invasive plants.
Historically the invasive plant debate and overall ‘weed’ agenda have been viewed by industry as an imposition of sorts. Industry members complain bitterly when a local authority deems a certain plant as invasive, usually because little or no effort has been made to engage industry in the process. Grow Me Instead charts a new course on the invasive plant issue, placing the Nursery and Garden Industry at the forefront of the agenda. We are stating that not only do we accept responsibility for non-invasive plant sales but we are prepared to consult with a wide range of stakeholders to ensure credibility of the entire program.

 

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Grow Me Instead – Promotion

The official launch of the Grow Me Instead (GMI) program in Queensland will occur during the week commencing October 12th. Primary Industries Week runs from October 12th-16th and this presents an excellent opportunity to promote both the GMI program and the broader industry. The exact date and venue of the launch are still to be determined however confirmation will appear in the next edition of Leaflet.

 

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Grow Me Instead Two plants worth fighting for!

The Grow Me Instead project has thrown up some interesting debate but clearly the most contentious inclusions are Murraya paniculata and Duranta erecta. Whilst these two plants are still widely grown and used in urban horticulture it is clear they present a significant challenge for Weed Specialists and Land Managers. I will provide some reasoning behind their inclusion in the three Queensland Grow Me Instead guides.

 

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Grow Me Instead

What is ‘Grow Me Instead’?
Grow Me Instead (GMI) is an Nursery and Garden Industry initiative to manage invasive plants. It is a proactive industry driven program that engages production and retail operators as well as other stakeholders in a collaborative effort to identify the most invasive of common garden plants and recommend a series of alternatives that should be ‘grown instead’. All other states and territories either have established GMI booklets or are in the process of printing them.

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Growing Media Calculating Air Filled Porosity In-house

Why do you need to know the physical properties of your growing media?? Having visited more than a couple of nurseries over the years it becomes readily apparent that there are as many growing media recipes as there are growers who use them. This may become an issue if a grower from one nursery decides that they prefer the growing media of another nurseryman or if a particular grower decides he wants to change their media for whatever reason.

 

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Chemical Properties of Growing Media

Last month’s article was concerned with the physical properties of growing media and how to go about analyzing these characteristics. This month’s article will continue this theme but will look at the chemical properties of growing media. Understanding the chemical properties and their possible interactions is actually quite complex. Hence this article will only touch on a few key points, other key areas such as the buffering capacity of mixes will not be covered in this article.

 

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Grow Me Instead – Launch for Darling Downs and South West

The Grow Me Instead project has provided a wonderful opportunity for the Nursery and Garden Industry to put our environmental credibility on show. It is a real feather in our cap to take this proactive stance on invasive plants; showing government and the community we care about the environment and are prepared to take positive action to reduce the impact of invasive plants.

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Water Retention Efficiency of Growing Media

Water retention efficiency (WRE) is a measure of the ability of a growing media to hold water applied from irrigation and this influences how long the irrigation must be run to wet up the media. An Australia wide survey
has shown that the WRE of commercially available growing media varies considerably, and suggests that the choice of growing media can influence water consumption and the quantity of nutrient runoff produced from a sprinkler or drip irrigation system.

 

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Growing Media pH and EC Testing

The pH measures the hydrogen ions in the growing media, while EC (electrical conductivity) measures the soluble salts in the mix. The pH and EC of the growing media should be in accordance with the plant’s requirements because different plants can have different preferred pH and EC ranges (see Container Media Management; K. Bodman & Dr. K.V. Sharman which can be purchased from NGIQ).

 

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Growing Media Water Holding Capacity & Wettability Testing

Water Holding Capacity Testing
The Water Holding Capacity (WHC) of a growing media measures the amount of water that a growing media can hold without causing plant stress. The WHC is largely determined by the amount and type of pore spaces available in the growing media, however the height and shape of the growing container also influences the growing media’s WHC (see Container Media Management; K. Bodman & Dr. K.V. Sharman which can be purchased from NGIQ). EcoHort guidelines recommend a WHC of greater than 40% (see EcoHort Guidelines from NGIQ).

 

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Growing Media Air Filled Porosity Testing

The air filled porosity (AFP) of a growing media is the percentage of its volume that is air after being saturated with water and just after it has stopped draining. Below is the method used in the Australian Standard for Potting Media for testing AFP.

 

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Growing Media: The Benefits of Coir Fibre

Coir or coconut fibre is the fibrous material that exists in the middle layer (mesocarp) of the coconut fruit. The long coir fibres are extracted from the coconut husk and used in the manufacture of brushes, twine and other products, while the short fibres have been shown to have excellent physical properties which can contribute to significant growth benefits for nursery plants.

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Growing Media Workshops Held in Far North Queensland

In response to requests by production nurseries in Far North Queensland (FNQ) for industry hands-on workshops about the use and testing of growing media in production nurseries, two Growing Media Workshops were held in May 2013 in Cairns and in the Atherton Tablelands. Both workshops were presented by Thea Pobjoy, the Northern Queensland Farm Management Systems Officer (FMSO) for the Nursery & Garden Industry Queensland (NGIQ).

 

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Growing Media pH and EC Testing: Method (for soil-less growing media)

The pH measures the hydrogen ions in the growing media, while EC (electrical conductivity) measures the soluble salts in the mix. For optimal plant health, the pH and EC of the growing media should be in accordance with the plant’s requirements because different plants can have different preferred pH and EC ranges (see Container Media Management; K. Bodman & Dr. K.V. Sharman which can be purchased from NGIQ).

 

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Growing Media Physical Properties

Air filled porosity (AFP), water holding capacity (WHC), bulk density, shrinkage, wettability and water retention efficiency (WRE) are all physical properties of growing media that influence plant growth and ultimately plant health.

 

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Growing Media Air Filled Porosity Testing

The air filled porosity (AFP) of a growing media is the percentage of its volume that is air after being saturated with water and just after it has stopped draining. Below is the method used in the Australian Standard for Potting Media for testing AFP.

 

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Growing Media Calculating Air Filled Porosity In-house

Why do you need to know the physical properties of your growing media?? Having visited more than a couple of nurseries over the years it becomes readily apparent that there are as many growing media recipes as there are growers who use them. This may become an issue if a grower from one nursery decides that they prefer the growing media of another nurseryman or if a particular grower decides he wants to change their media for whatever reason.

 

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Chemical Properties of Growing Media

Last month’s article was concerned with the physical properties of growing media and how to go about analyzing these characteristics. This month’s article will continue this theme but will look at the chemical properties of growing media. Understanding the chemical properties and their possible interactions is actually quite complex. Hence this article will only touch on a few key points, other key areas such as the buffering capacity of mixes will not be covered in this article.

 

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Growing media and Irrigation

Nursery irrigation should be applied at a rate that matches the ability of the growing media to absorb and hold the water that is applied. The best designed irrigation layout operated at the correct pressure cannot deliver the required efficiency if a significant portion of the applied irrigation is quickly draining through the growing media without being absorbed and held in the container. Ensuring the application of water matches the absorption rate of the growing media will take full advantage of the water holding capacity of the growing media. This application of water is known as the Mean Application Rate (MAR) and the past results from a national survey of over 200 nurseries showed an average MAR of 20.2 mm/h. Production nurseries should be seeking to achieve a MAR of between 5 & 12mm/hr, but there are many variables that can have an impact on the absorption rate such as the makeup of the growing media, the physical components, the air-filled porosity, the addition of wetting agents and polymer gels and scheduling techniques. A well designed premium growing media can greatly improve irrigation efficiency.

 

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Growing Media Physical Properties

An understanding of the physical, chemical and biological characteristics of a growing media can improve plant growth and your bottom line. In this article we look at the physical characteristics of growing media.
Air Filled Porosity - AFP.
AFP is the percentage of the growing media occupied by air after the media has been saturated with water and allowed to drain. More air in the media will improve root growth, but a higher AFP may require more frequent watering and consequently nutrient leaching may be increased. Container depth has a significant effect on AFP as, in shallow containers, the AFP is reduced due to the greater proportion of media occupied by the saturated media in the bottom of the container. AFP will also decrease during the growing cycle, but this can be compensated, to a degree, by the increased ability of the plant to extract water from the growing media, reducing the amount of pore space occupied by water. A range of 13-30% AFP is considered to be acceptable under EcoHort guidelines for general nursery stock.

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Will any growing media suffice to grow the best plants possible?

the growing of plants there are fundamental aspects which need to be fulfilled to allow
the plants to grow and develop to their optimal genetic potential:
• light (typically sunlight as a source of energy for photosynthesis)
• temperature (suitable range for plant type)
• space (density to allow air, light and growth and development of the plant)
• Carbon dioxide (for photosynthesis)
• water (for essential plant processes)
• oxygen (supplied to root zone for optimal root function)
• nutrients (growth and development), and
• the provision of a growing environment devoid of plant pests, pathogens and weeds.

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Some Organic Growing Media Components and their Characteristics

In last week’s article we mentioned briefly that nurseries should have the correct physical, chemical and biological properties in their growing media. The question is have you actually tested them on site? Listed in the back of “Container Media Management” by K.Bodman and Dr.K.V.Sharman, 1993. This is a complete guide for nurseries to analyse their growing media. It discusses the analytical methods for determining Air Filled Porosity, Total Water Holding Capacity, Wettability, Volume and Bulk Density, pH and EC (Electrical Conductivity), Toxicity Index and Nitrogen Drawdown Index.

 

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Media pH Management, Liming Rates

Understanding pH management starts with your choice of growing media components, the crops you choose to grow in them and how you intend on irrigating them. Currently there is a wide range of media components available to the nursery industry. They may include but are not limited to: pine bark, peat, coir, sand, perlite, vermiculite, absorbalite, peanut shell, rice hulls and the list goes on. Some decisions on which components to use are dictated by what is available locally and for some it may be the cost of the growing media landed on your property.

 

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Growing Media pH and EC Testing

The pH measures the hydrogen ions in the growing media, while EC (electrical conductivity) measures the soluble salts in the mix. The pH and EC of the growing media should be in accordance with the plant’s requirements because different plants can have different preferred pH and EC ranges (see Container Media Management; K. Bodman & Dr. K.V. Sharman which can be purchased from NGIQ).

 

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Growing Media pH and EC Testing: Method (for soil-less growing media)

The pH measures the hydrogen ions in the growing media, while EC (electrical conductivity) measures the soluble salts in the mix. For optimal plant health, the pH and EC of the growing media should be in accordance with the plant’s requirements because different plants can have different preferred pH and EC ranges (see Container Media Management; K. Bodman & Dr. K.V. Sharman which can be purchased from NGIQ).

 

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Growing Media Physical Properties:

Air filled porosity (AFP), water holding capacity (WHC), bulk density, shrinkage, wettability and water retention efficiency (WRE) are all physical properties of growing media that influence plant growth and ultimately plant health.

 

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Water Retention Efficiency of Growing Media

Water retention efficiency (WRE) is a measure of the ability of a growing media to hold water applied from irrigation and this influences how long the irrigation must be run to wet up the media. An Australia wide survey
has shown that the WRE of commercially available growing media varies considerably, and suggests that the choice of growing media can influence water consumption and the quantity of nutrient runoff produced from a sprinkler or drip irrigation system.

 

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Growing Media Water Holding Capacity & Wettability Testing

The Water Holding Capacity (WHC) of a growing media measures the amount of water that a growing media can hold without causing plant stress. The WHC is largely determined by the amount and type of pore spaces available in the growing media, however the height and shape of the growing container also influences the growing media’s WHC (see Container Media Management; K. Bodman & Dr. K.V. Sharman which can be purchased from NGIQ). EcoHort guidelines recommend a WHC of greater than 40% (see EcoHort Guidelines from NGIQ).

 

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Growing Media Wettability Testing

The ability of a growing media to take up water effectively once it has dried out is critical to the growth of plants and the ability of the media to become wet again. This is known as wettability. Testing for wettability isn't difficult and can be done at minimal cost with some basic equipment

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Growing Media pH and EC Testing

Knowing the pH and Electrical Conductivity or EC of your growing media can help you to grow better and more consistent crops. Testing procedures aren't difficult and can be done at minimal cost. This video shows a process for carrying out a practical on-site pH and electrical conductivity

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Growing Media Water Holding Capacity Testing

Knowing the amount of water held within a growing media, referred to as Water Holding Capacity (WHC) of your growing media can help you manage irrigation scheduling more effectively and ensure plants have adequate moisture. 

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Growing Media Air Filled Porosity Testing

Plant roots require air as well as water to remain healthy. The amount of air held within a growing media is referred to as Air filled porosity or AFP . Testing procedures for AFP aren't difficult and can be done at minimal cost with simple equipment built from readily available materials and a little bit of time. This video shows a process for carrying out a practical on-site air filled porosity test on growing media.

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Coir Video

Coir, coir fibre pith or coconut fibre is a one hundred percent natural, sustainable and renewable product. Coir is a ‘peat like’ byproduct produced from the processing of coconut husks, and is composed of the fibrous material found between the hard, internal shell and the outer coat of a coconut. Coir is lightweight, retains moisture and is an affordable growing media substrate or component for adding to growing media blends, producing stronger, healthier and more fibrous root systems.

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Calibrating Meters

pH and Electrical Conductivity meters are extremely useful pieces of equipment used to measure and monitor basic chemical characteristics of water and growing media. Regular and correct calibration of this equipment is necessary to ensure the results are as accurate as possible. The following video describes the basic procedures for calibrating pH and EC meters.