When do you lime Leyland cypress trees?

At the time of planting and in the fall describe the times when Leyland cypress trees can be limed. The evergreen hedge and screen in question (Cupressus x leylandii) flourishes in slightly acidic to neutral soils, especially in pH (power of hydrogen) ranges from 5.0 or 5.5 to 6.0 or 6.5. Soil tests need to be conducted about every three to four years and lime applied if results suggest raising a pH at or below 5.0 into the safety zone up to 6.5.