Articles
CONTAINER MEDIA: THE AUSTRALIAN EXPERIENCE
Article number
891_35
Pages
287 – 295
Language
English
Abstract
In Australia almost all plants produced by nurseries are grown in containers.
The growing medium varies with location, but is mostly based on the composted bark of several (exotic) pine trees.
Other bulk components are pine and eucalyptus sawdusts and coir fibre dust.
All media are soilless; many are now sandless.
Media for large permanent planter boxes are often based around washed bottom ash from coal-fired power stations plus organic components.
The foundations of the use of soilless media were laid down by the late David Nichols and colleagues in the late 1970s.
A key finding was the need for much reduced phosphorus additions, especially for proteaceous species and some native legumes.
Almost all nurseries buy fully formulated medium that is produced by a small number of large specialist producers.
Formulation is based on the provisions of the Australian Standard for Potting Mixes.
This prescribes limits for physical and chemical properties, based on standard laboratory analyses.
Growers specify such properties as air-filled porosity, rewettability, pH and base nutrient content.
All media have trace elements added to them by the producer.
Most growers use controlled-release fertilisers as the main (often only) source of nutrients for their plants.
A very wide range of plants is grown.
Most vegetables are started off in cells.
Tree plantations generally now start off in cell trays.
In recent years drought has led to major changes in the mix of plants being grown for sale to gardeners and landscapers.
Many more Australian native plants and plants from other Mediterranean climate areas are now grown in southern Australia than previously, with a marked decline in the use of northern hemisphere species.
The growing medium varies with location, but is mostly based on the composted bark of several (exotic) pine trees.
Other bulk components are pine and eucalyptus sawdusts and coir fibre dust.
All media are soilless; many are now sandless.
Media for large permanent planter boxes are often based around washed bottom ash from coal-fired power stations plus organic components.
The foundations of the use of soilless media were laid down by the late David Nichols and colleagues in the late 1970s.
A key finding was the need for much reduced phosphorus additions, especially for proteaceous species and some native legumes.
Almost all nurseries buy fully formulated medium that is produced by a small number of large specialist producers.
Formulation is based on the provisions of the Australian Standard for Potting Mixes.
This prescribes limits for physical and chemical properties, based on standard laboratory analyses.
Growers specify such properties as air-filled porosity, rewettability, pH and base nutrient content.
All media have trace elements added to them by the producer.
Most growers use controlled-release fertilisers as the main (often only) source of nutrients for their plants.
A very wide range of plants is grown.
Most vegetables are started off in cells.
Tree plantations generally now start off in cell trays.
In recent years drought has led to major changes in the mix of plants being grown for sale to gardeners and landscapers.
Many more Australian native plants and plants from other Mediterranean climate areas are now grown in southern Australia than previously, with a marked decline in the use of northern hemisphere species.
Authors
K.A. Handreck
Keywords
container media, analysis, Australian Standard for Potting Mixes
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