Moved into our newly built bungalow on green field site 2005. Following year planted hedge on two sides of our patio, Same time, same batch of plants, same treatment and on same day. One side, north facing, had some shelter from patio, 1 to 2 feet.. Other side open to south, no protection. Sheltered side doing very well. Open side not nearly as strong and “bare”.
Conditions can vary very dramatically in even a small area. This is likely to the effect of shelter but it might also be possible that soil conditions vary too. Escallonia is quite wind-resistant and will generally establish well even in a windy spot, but might take more time to do so.