Fertilisers are different to soil improvers and compost. Fertilisers feed the plant while compost and soil improvers feed the soil. When you add fertiliser to your soil, you provide your plants with three basic chemicals, often abbreviated to their chemical symbols; nitrogen (N), phosphorus (P) and potassium. Packaged fertilisers list the amounts of NPK each product contains, in ratio form.
As a general rule, nitrogen encourages leafy growth, phosphorous stimulates overall growth while potassium assists with flowering.
Liquid or granules?
Liquid fertilisers are useful for getting young plants established as quickly as possible. Plants suffering from deficiencies may also benefit from a liquid fertiliser boost. Granular fertilisers release nutrients to the plants over the course of a few months. This means that you won’t need to fertilise as often, and nutrients won’t be wasted by washing away or leaching into the groundwater.
Specialised fertilisers
Some plants benefit from specialised fertilisers, but you don’t have to buy a different fertiliser for every plant in the garden.
Australian native trees and shrubs
Many Australian native plants are sensitive to phosphorous - too much can kill them. Use a specially formulated lowphosphorous fertiliser.
Young & newly planted trees
Use a fertiliser high in nitrogen for strong growth.
Gardenias, camellias, azaleas & roses
These are acid-loving plants so use a specifically-designed fertiliser to give them the nutrients they need.
Fertilising tips
- Always follow the product’s application instructions carefully.
- Water well after applying granular fertiliser, especially on lawns.
- Spread granules evenly to avoid pockets of over-fertilised soil.
- Store unused product in a cool, dry place, clearly labelled.
