Q.I have some box plants that need raising in their planter
I have some three year old Box trees that are in a raised planter but the soil level has sunken quite dramatically. I want to lift them add soil and re-plant but not sure if this is a good idea and if the moving will effect the trees
You certainly can lift the plants, check the roots and detangle them gently if needed. Add new, good quality potting soil and replace into the container or move up 1 size in containers. Add a bit of new soil to the top of the container after you have adjusted the height.
It does help to water the container well 1 or 2 days prior to doing this so your soil is not too dry or overly wet.