Art Knapp gave me lime sulphur in the summer for peach leaf curl and they said to use it in the winter. So…is that now? And can I use it on other plants? Thank you!
It should be applied sometime in the next few months before the leaves start to emerge. Wait for a few days of dry weather to apply.
On my apple trees I like to give 2 applications spaced a month apart. It is usually applied with horticultural oil, as they often come as a kit together. Avoid spraying nearby conifers or plants in leaf.