You honestly cannot believe a rose that your mother planted 50 years
ago is still living. If you do believe in this then i suppose you
would believe anything your mother told you?
There are of course, countless examples of roses living this long or
longer. My own mother who is 90 years old has a 'Peace' rose that is
planted in her garden and growing well that was planted in the 50's.
Still blooms every year, and hasn't reverted to the root stock.
Go into any old neighborhood in America and you will find roses on
every single block that are of the same era or older.
The 'Texas Rose Rustlers' organization is predicated on the idea that
there are old roses all over the place that can be 'discovered'.
Varieties that were thought to be lost to history.
Own root roses are more likely to survive a long time than budded or
Zone 6 in Salt Lake City