Fertilizer Effects

Plants require a small amount of nutrients such as nitrogen and potassium for growth along with even small amounts of other nutrients such as phosphorus and magnesium. For these nutrients to be absorbed by plants it needs to be dissolved in water first. Nutrients which are not taken up by plants make their way to our waterways and contribute to algae blooms which can be toxic to our aquatic environments.

Lawn maintenance

  • Different grass species require different nutrient level, buffalo grass requires much less nutrients the couch grass.
  • Only apply fertilizer if nutrient deficiency occurs (e.g. Yellow)
  • Do not fertilize during summer or winter. Summer encourages an increase in watering and heavy rains in winter wash the fertilizer away.
  • Use organic fertilizers such as fish emulsion, composted manures, worm castings and rock dust
  • Nutrients such as Sulphur, Magnesium, Calcium and trace elements of Copper, Iron, Manganese, Zinc, Molybdenum and Boron may also be used for growth.a

Chemical Pollution

Chemicals that get into the storm water drains may harm the waterways and the environment Storm water pollution includes:

  • Lawn clippings and other garden waste
  • Leaves from deciduous trees
  • General household rubbish
  • Bread and other food fed to water birds
  • Detergents and cleaning products
  • Oils and petrol
  • Fertilizers, herbicides, pesticides
  • Building sand and soil


There is evidence to suggest that Aboriginal people have used Blue Gum Lake for the past 38,000 years. Local Nyoongar Aboriginal tribes used Blue Gum Lake as a seasonal source of food and fresh water. It was also used as a transport route for the Aboriginal people, passing through many of the lakes south of the Swan River.

Importance of wetlands

Wetlands play a vital role in the environment, principally water purification, flood control and shoreline stability. They are highly specialized “organs”. They help maintain the overall health of the environment by filtering and controlling the water that passes through them. In this case for the Swan River, the natural process of wetlands involves seasonal inundation of the wetland in winter, and drying in the summer. In addition to seasonal changes, water levels are dependent on rainfall, groundwater levels and discharge of storm water. It is natural for wetlands to dry out in summer, and is an important process for the health of the lake. This helps to reduce mosquito infestation and assists natural wetland vegetation that needs a period of dryness.

Environment friendly gardening tip

Plant local plants in your garden. Their beauty and the animals they attract will surprise you. Local plants are species that would naturally occur in your neighborhood and are therefore adapted to the local climate and soil.

  • Local native plants need less water and fertilizer
  • Minimize the use of deciduous trees as falling leaves can enter storm water drains and contribute to nutrient problems in waterways
  • Group plants with similar water/fertilizer/shade requirements
  • Plant deep-rooted perennials rather than annuals
  • Use high quality, coarse mulch in garden beds to reduce watering (this minimizes the amount of nutrients seeping through soil and into groundwater)