Place one cup of quality compost or worm castings into a netted back. Fill a 20 litre bucket with rain water or if using tap water allow to stand for 24 hours to give the chlorine time to dissipate. Place the bag of compost into the water and add an air stone connected to a pond aerator that puts out approx 1000 - 2000 litres of air per hour. Now add 2 tablespoons of Kelp, 2 tablespoons of Molasses and 2 tablespoons of Full Fat Soya Bean Meal. Each of these ingredients are available from your local livestock supply shop. Allow to bubble away for 24 - 36 hours. Place a cup of the brew when finished into a 9 litre watering can or 2 cups into a 5 litre knapsack spray and apply to the soil preferably early evening so as no to harm the microbes with direct hot sun. Entire brew should be used within 24 hours after brewing is completed.


This recipe is from Kevin Handreck’s excellent book Gardening Down Under, CSIRO 2001.

Lightly moisten 10 litres of compost or animal manure and mix in one cup of iron sulphate.
Dig holes about 20cm deep in the plant’s root zone. Three for a rose bush or 6-8 for a big grevillea. Put the iron compost into the holes and water well.
The plant roots will soon grow into the organic matter. The treatment lasts for several years, unless the irrigation water is highly alkaline.