"MARY, Mary quite contrary how does your "garden grow" runs the old nursery rhyme.
The answer lies in three key nutrients: nitrogen (N) phosphorous (P) and potassium (K). These are the macronutrients and all fertilisers sold in nurseries will carry an NPK table showing the percentage of these three.
While these three nutrients do many things, broadly speaking they act as follows.
■ Nitrogen needed for leafy foliage growth
■ Phosphorous to improve formation and quantity of fruit, flowers and seeds
■ Potassium to improve the quality of existing fruit and flowers e.g. sweeter fruit
In addition there are micronutrients such as magnesium, sulphur and calcium along with trace elements like iron, copper and zinc required to ensure healthy growth.
Most plants require all the above to thrive but be aware that Australian natives have evolved in phosphorous-deficient soils so most fertilisers for natives have very low levels of, if any, phosphorous.
There are many symptoms of deficiencies of these nutrients and they require a skilled eye to diagnose the remedy.
The main ones to look out for are yellowing of leaves or stunted growth. Take a sample to your local nursery where skilled staff can assist you.
Even if all the above are available to plants, if the pH of the soil is not right then your plants will not thrive.
Soil pH is a measure of how acidic or alkaline your soil is.
■ Too alkaline and plants cannot absorb iron.
■ Too acidic and they struggle to absorb phosphorous
Likewise take a soil sample to your local nursery and they will help measure the pH of your soil.
For more inspiration contact Michael Lee at www.greenthumbgardener.com.au.