I am no expert but that seems short. The Azaleas at my childhood home's garden(lower NY) were there when my folks bought the house 35 years ago and are still going strong despite 5 kids, a series of dogs and periods of neglect.

of course you will see in an earlier post my own didn not survive one winter :(

There is no such thing as the life span for all azaleas. There are so many variables that it would vary from a couple weeks in areas where the plants were really struggling to perhaps 1,000s of years in their native habitats. So maybe evergreen azaleas in coastal Texas would typically get straggly looking in 20 years, that is by no means typical for the rest of the world. Some varieties will thrive and live forever. Some will struggle and always look like they are going to die or actually die. My rhododendron and azaleas are mostly over 40 years old and look like they will last forever.

I may just be gullible or uninformed, but I know of some Azaleas in my area that have been around since the revolutionary and civil war periods.

Sorry, didn't mean to post that in this thread, thought I was making a new one.

There are Indica azaleas in my garden that have been here for more than fifty years, planted by my late MIL. They are in an ideal climate, which may explain the longevity.
Nell

Azaleas at my grandparent's house in Charleston are at least 150 years old.