Being the first month of winter means it’s the first of three ‘bench sprays’ with diluted lime sulphur over the next three months. I like to do any spraying on the first weekend of the month. That way I remember to do the task and it just becomes part of the winter monthly routine. Mix 30ml of lime sulphur to one litre of water. Spray liberally over any benches you have. This will kill any fungal spores as well as pests that are lurking around biding their time to attack.
Spraying trees with diluted lime sulphur in winter helps kill pests and fungal spores but there are a couple of very important steps to follows to ensure trees are not affected or at worst killed.

  1. The first step is to water trees and pots thoroughly so the soil is drenched and all parts of the tree (trunk, branches etc) are wet prior to the application of diluted lime sulphur.
  2. Place several layers of newspaper or similar around the base of each tree to protect the soil from any spray. Pay attention to ensure that the newspaper “hugs” the trunk of the tree so that it will catch excess spray dribbling down the trunk.
  3. Mix lime sulphur with water. I use 30ml with 1 litre of water, some people use as little as 5ml with 1 litre of water.
  4. Use a fine jet pump, spray the branches and trunks of the tree. Don’t drench the tree to the point that you have a huge river running down the trunk.
  5. Leave the newspaper in place until all drops of lime sulphur have stopped falling from the tree. It is important to minimise the opportunity of lime sulphur entering the soil/ root system. Don’t re-use the newspaper on another tree.

The trees will have a whitish look to them after the spraying but this will diminish and disappear within a few weeks with watering and natural weathering.

Now the contentious bit… of those people who choose to spray trees with diluted lime sulphur, some choose to only spray deciduous trees, others spray all trees (and their leaves).

To my knowledge, no one sprays trees in flower (as it will likely destroy the flowers).