If you are keen to make your own nourishing tree paste for pruning cuts, for painting on stock damage on trunks, or even as a tonic or pick me up for a tree that needs some helping along in the winter, you might like to try this recipe.
3 parts potters clay or soil containing clay
4 parts fresh organic cow manure
2 parts either silica sand or diatomaceous earth
Mix well with water until it is a runny paste. Scrub the tree bark with a scrubbing brush to remove algae, lichen, overwintering insects etc, then apply nourishing paste with a paint brush.
The clay makes the paste stick well to the bark as long as it has 24 hours to dry before it rains. I found the easiest place to get it was from a potter. The diatomaceous earth keeps pests away and helps strengthen the tree. I mix it in a bucket and apply with a brush during pruning on all the bigger tree branches and pruning cuts.
“The underlying purpose of tree paste is twofold. Clay as a tissue rejuvenator. Manure as a rich source of microbes. Nutrition is always good” Michael Phillips