My front garden was originally tiled right over. Rather than dig up some
tiles for a flower bed, I simply laid 18 inches of soil on part of it. In
this bed I have a couple of small conifers bushes (about 2 feet high) which
have suddenly decided to get quite a bit bigger this year, after about three
years of sitting there quietly and hardly growing at all.

To keep them 'small' I try trim the foliage back. But for better longer
term results should I dig them up and try to trim the *roots* back, or will
trimming the tops be enough to do the job? Thanks for advice.