What Are Environmental Weeds

1. What Are Environmental Weeds?
“Garden plants are the biggest source of weeds in this country totalling 70% of Australia’s combined
agricultural, noxious and natural ecosystem weeds”. (CSIRO 2005 Report ‘Jumping the Garden
Fence’). Governments and volunteers dedicate enormous resources to controlling invasive plants
that destroy biodiversity.
Weeds in the garden create a chore that needs to be attended to in order to keep our ornamental
plants healthy and to make the garden more attractive. When plants become weeds in our bushland
and waterways, however, they pose a much more serious problem.
An environmental weed may be one that we recognise as a common garden weed, such as White
Clover (Trifolium repens) or Soursob (Oxalis pescapre). They can also be ornamental plants
introduced from overseas, or Australian plants originating from outside the ‘local area,’ such as
Bluebell Creeper (Sollya hetrophylla) from WA or Sweet Pittosporum (Pittosporum undulatum) from
East Gippsland.
Environmental weeds can be of any plant type: annuals, perennial herbs, shrubs, vines, trees,
aquatics or succulents. Due to their ability to survive and spread over a wide range of conditions
these plant species are identified and classed as environmental weeds.
Environmental weeds compete with the naturally occurring local vegetation for light, nutrients,
water and space, often reducing its ability to regenerate. Their impacts on ecosystems can include
reduced biodiversity, loss of food sources and shelter (for animals and insects) and even choking of
rivers.
When deciding on what plant species to include in your home gardens please consider using plants
without potential for weediness, especially if you live near areas of bushland, coast, rivers or creeks.
There are many excellent alternatives to choose from and natural plant and animal communities may
benefit from your actions. Some of the plants that we grow in our gardens are able to propagate
themselves by seeds, cuttings or offshoots. Examples include Agapanthus that spreads by seed, the
berries from Cotoneaster spread by birds, and Ivy that can take root from a small piece of stem.
These plants may or may not be identified as Environmental Weeds, but we can reduce the
possibility of them ending up a problem in our natural areas and waterways with the following
methods:
Cut off old flower heads before they form berries or seedpods.s
Contain self-seeding plants, such as coriander to a specific area of the garden.s
Dispose of garden waste by composting or green waste collection.s
Don’t dump weeds and prunings on vacant land, in waterways or the bush.s
If you see someone dumping garden waste report it to your council.s
Restrict the root growth of creeping or suckering species with root barriers or pots.s
Avoid using plants that are known environmental weeds in your local area. If you are not sure asks
at a SGA nursery, contact your local council for information on weeds that are a problem in your
area or visit the website: www.weeds.org.au .
Consider replacing any environmental weeds in your garden with local plants or exotic plants thats

2. are not invasive.
Avoid transporting seeds or Australian plant material interstate or overseas, where it may becomes
an environmental weed.
Choose sterile forms of species that set seed.s