The optimum time to plant or transplant is from late September, then by incremental changes, less favourable until next summer.
The earlier trees, hedge and shrubs are transplanted during this period the longer they have in their new locations, to begin to establish prior to it becoming hot and dry. This enables them to start to create a root system to support themselves. This reduces planting/transplanting stress, the level of aftercare required and increases the quality of transplant.
Deciduous trees/hedges/shrubs transplanted in autumn, before leaf drop, in our experience only enter autumn (leaf fall) phase early.
The benefit of planting/transplanting early in this cycle is only marginally eroded as the calender progresses.
Later in this period the planting/Transplanting process does not need to be amended until it gets into Spring and Summer. We amend the process with larger rootball if transplanting / root preparation and always increased aftercare. Also we cut down the time between delivery and planting of trees and shrubs.