Biodynamic Management of Avocados

Avocados need good biodynamic management. They are heavy feeders and need applications of at least 1 wheelbarrow compost under the canopy in Autumn each year and a good cover of carboniferous mulch – wood chips are ideal. During the growing season a green manure such as cow peas can be planted under the tree or grass mulch from slashing between the trees can be spread under the trees.

Avocados also respond to rock dust – highly paramagnetic basalt dust is the best. If you can source rock dust from local quarries it can be put on at the rate of 1 trailer load/large tree. This would suffice for up to 10 years. Smaller amounts can be incorporated into your compost as you make it and spread under the trees in this form. Rock phosphate and biochar incorporated into your compost as you are making it will also be of benefit to avocados.

Biodynamic Paste is also a favorite of avocados and can be thickly painted on the bark and large branches and any wounds or pruning cuts. A biodynamic soil spray (Horn Manure or Combined Soil Preparation) should be put out at least four times per year followed by the atmospheric spray (Horn Silica with Summer Horn Clay and Fresh Equisetum). Do not spray out Horn Silica when avocados are flowering.

Biodynamic Management of Phytophthora cinnamomi in Avocados

A member who grows Biodynamic Advocados at Telegraph Point on the mid-north coast of NSW has had success using alternative sprays of fresh Casuarina tea and Horn Manure (500). Young and old trees infected with Phytophthora have recovered.

Our member mixes Horn Manure for one hour at the recommended rates of 85g in 32 litres of water and drenches the drip line of the affected trees with it. The next day he brews up fresh Casuarina tea* with a fire under an old copper or cast iron bathtub – cover 1/3 volume male Casuarina needles with 2/3 volume good quality water – bring to the boil and simmer for 20 minutes then strain off liquid. Our member mixes 25 litres of frech Casuarina tea in 145 litres of water and drenches the leaves and the root zone of infected plants.

This program runs for three successive days each week over three weeks. He drenches around the drip line with stirred Horn Manure the first afternoon and then he drenches the leaves and soil with fresh Casuarina tea the next afternoon and on the third afternoon drenches with Horn Manure again. The next week he sprays over three successive days Casuarina tea then Horn Manure then Casuarina tea and in the final week he goes back to Horn Manure then Casuarina tea then Horn Manure.

Recovery occurs after only 1 week of spraying. The next two weeks spraying are worthwhile to insure against re-infection.

*Equisetum tea can be used to replace the Casuarina tea.