I have very tall cedar hedges, probably over 12'. This may be a dumb question, but is it possible to cut a cedar hedge in half and replant the top half? Will roots grow from the top half of the stump? Or do I need to do it using a small branch and start from there? The reason I'm asking is that we have some bare spots and some cedars that are dying which I'd like to fill and replace. Getting full grown, matching cedars may be difficult since I have no idea what the original type is. Using the full grown ones I can fully fill in the voids since they are more rectangular/box shape rather than conical tree shape. I was gonna trim down those tall hedges anyways. I know it isn't good to lob a tree off in half and expose the top, but if I could regrow the top half, then it would be justified to wait until the hedge is tall enough. Cutting it in half would still retain a very tall bottom. Instead of tossing it in the bin as tree clippings, it would be good if I could salvage and replant them.
No, you can't stick the cut tops in the ground and expect rooting and growth. If you cut the existing plants in half you may then later have to take the whole thing out and start over in order to have an attractive hedge. To maintain a complete furnishing you have to avoid cutting back beyond the outer layer that still has foliage on it. To have full sides in the lower half you need to shape the hedge as it develops so that the upper half is narrower than the lower, does not shade it too much.
Take a cutting to a good garden centre. Ask them to match it to the type of Cedar you have....or walk around and match it by yourself.
