Dormant Spray KitTo protect your trees and shrubs from destructive insects and fungi you should spray them with a Dormant Spray Kit! The kit combines horticultural oil and lime sulphur to combat the overwintering pests before they do any damage. Apply when: The tree or shrub is dormant and the buds have not opened It is 0 degrees Celsius or above for a minimum of 24 hours There is little to no wind (to prevent drift) There is no precipitation (rain snow) during the