Fertilise Wise

Using less fertiliser

Healthy soils often need little or no fertiliser. Gardens with healthy soil thrive and are cheap to maintain. Healthy soil holds water and nutrients, feeding your plants and protecting our waterways. Experienced gardeners care for their soil by:

• adding compost to build the soil structure
• applying mulch to protect the soil
• installing edging to prevent soil erosion.

Choosing safer fertiliser

Strong fertiliser products can burn plants and release nutrient pollution into the waterways. Safer fertiliser options include:

• Products that are low in phosphorus (often labelled ‘for natives’). The amounts of key nutrients must be shown on fertiliser product packaging. Look for the letters ‘NPK’ – they stand for nitrogen, phosphorus and potassium. Look for a ‘P’ number (%) of 2 or less.
• Controlled release (also called slow release) products. These coated pellets deliver the nutrients evenly over many months.
• Products containing rock minerals or trace elements. They give a balanced feed to plants and soil.
• Composted and pelletised organic products that hold water and introduce micro-organisms to the soil.

How much fertiliser to use

Did you know that there is a growing movement where many professionals who manage sports ovals and golf courses use very little added fertiliser? Instead, these professionals commonly use lawn clippings (from regular mowing) and a sprinkling of compost to return the right amount of nutrients to the soil.

Do your plants need fertiliser? Avoid fertilising just because it’s a regular routine or your plants look yellow. Yellow leaves could reflect a problem with soil microbes, trace elements, or even too much fertiliser in the soil.

When using your choice of eco-friendly fertiliser:

• Read the packet for recommendations on the amount to apply per square metre. Use less than it says on the packet.
• Measure the area that needs to be fertilised.
• Measure out the fertiliser to suit the area; and
• spread it evenly over lawns (a hand operated spreader can help),
• apply it directly around plantings, or
• dig it in before planting out new plants.

When to use fertiliser

Match your fertiliser use to the needs of each garden area.

• Lawns – apply once in spring and, only if needed, again in early autumn.
• Ornamentals – apply in spring and autumn.
• Native planting – apply only very low- phosphorous (P) fertiliser in spring for new plantings, and not at all for established plants.
• Productive (vegetable or fruit) gardens – apply:
  • when planting, and then
  • quarterly.