There is supposed to be difference in flavor of hops grown in different soils...I can't speak from personal experience since my taste buds are not that highly refined.
What I can tell you is that most homegrown hops will have more flavor/aroma than commercially purchased ones. This is because they are usually fresher, handled more gently and are dried at lower temperatures which preserves more of the oils and aroma than commercially produced hops. So if you are trying to compare home grown hops to ones purchased at the store, its somewhat like trying to compare sweet corn from your garden to sweet corn shipped from California up to the midwest. The stuff from CA may have been better to begin with, but it has been so abused in transport and processing that you would never know.