Rhododendrons: Buds not blooming!! :(

My father in law has a beautiful rhodo in his yard not in full sun but in morning and late afternoon sun...It has not flowered for the past couple of years..All the buds are there, but they remain unopened..No visable damage to the plant..leaves are still dark green..Any ideas why the buds remain unopened? Thank you!

 

You need a little more explaination as it sounds like you are saying it has the same flowerbuds for two years waiting to bloom.

Normally Rhodies will start to form new terminal buds in the fall -- some will be longer and narrower growth buds and some the rounder flowerbuds. These will overwinter untill spring when the growth buds grow and the flower buds flower. Sometimes these buds burst into growth/bloom as winter hits and are damaged, calld bud blast. But bud blast can have other causes. Sometimes the buds are good, but a warm winter thaw or sun will cause them to swell and then a cold comes and freezes the buds and kill them. Warming but the sun during the day and freezing by night is a cause of bud blast. Sometimes it is a insect and/or fungus that cause bud blast.

But in most years the terminal growth will break into bloom and or growth in the spring. Sometimes with the later blooming varieties, leaf buds under the flower break into frowth well before the flower blooms and can almost hide the flower. If you lucky though, you have masses of flowers that bloom before the growth starts. Sometimes you get a second or even third growth sperts/blooms before winter especially in milder climates with a longer growing season. In the colder regions one flower/growth spurt a year is healthy while two may actually be damaging. Many of these aspects are a characteristic of one variety or another -- so it depends on what variety. However I have never seen or known of a rhody stay in bud (dormant?) for two seasons.