Trees and Vegetation
The Mitcham Council area is renowned for some of the last large remnant areas of Eucalyptus microcarpa (Grey Box Woodland). This plant association once covered vast areas of the Adelaide plains and the foothills. Present estimates indicate that there is less than 4% of this woodland plant association that has been retained in a natural state. In 1992 the Grey Box Woodland was rated as a priority 4 for conservation purposes.
There are many threats to the Grey Box Woodland plant associations including ever spreading housing development and the clearing of land for agriculture. The other not so obvious threat is that of weed invasion.
Many plants, even natives from elsewhere in the country, can become garden escapees and cause problems in our local bushland.
To help you make your garden 'bushland friendly', Council has prepared a Hills Planting Guide and a Plains Planting Guide, which list species indigenous to the local area. Use of these plants within a landscape will be in line with biodiversity guidelines. All plants listed are commercially available.
For future information on planting species to enhance our natural biodiversity visit the Urban Forest Website.
In Australia there has been a history of introducing plants either for agriculture or for pleasure, and it is over the last 20 years that we have seen the affect this has had on our often fragile and unique native vegetation.
Many of the native species rely on a naturally occurring balance in order to survive. Introduced plants can alter that balance by providing too much shade or taking up the much-needed nutrients from the soil. Many of the more aggressive introduced plants have completely smothered out some of the fragile native species. The severity of pest plant infestation can be affected by several factors including: growth patterns, habitat and adaptability to receiving environments (soil types, rainfall, shaded areas, water ways etc).
A commonly asked question is when does a plant become a weed? Some would argue that any introduced plant is a weed, while others would suggest that any plant that can self propagate and proliferate in a naturally occurring environment could be considered a weed. Still others consider any plant that has an affect on the production of foods is a weed and if it does not affect cropping and livestock it is not a weed.
The City of Mitcham has produced a list of invasive plants that we ask you to consider removing from your garden area, helping to ensure that they do not spread into woodland area. For advice on removing weeds from your garden view our document on removing weeds.
A report has also been prepared by Neville D Crossman and David A Bass, Environmental Weeds Group, School of Geography, Population and Environmental Management, Flinders University, May 2002, which maps Environmental Weeds on the Western Slopes of the Mount Lofty Ranges.
The olive is one plant that has adapted readily to the hills environs around Adelaide and has become a particularly troublesome invasive weed. Their rapid seeding and survival techniques means that they are tough competition for native plants and are difficult to eradicate.
The Council has prepared a document on the Olive Tree, titled "The Olive Tree is an Amazing Plant". It describes the impacts of the Olive Tree on The City of Mitcham's environment and the efforts being made by Council to eradicate the weed.
If you have woody weeds in your garden and require some advice on removing them, view our document on Removing Weeds. Small seedling can be hand-pulled but established plants generally require poisoning.
Declared Plants in South Australia
Landholders are legally obliged to control certain plant species on their property. These are known as 'declared plants'. Declared Plants in South Australia are regulated under the Natural Resources Management Act 2004 (NRM Act).