I planted two Rhododendrum plants a couple of years ago and they have never flowered. I'm not sure why they are'nt flowering. My Azaleas are doing just fine. I live in upstate NY.
thanks for any help that you can provide..

Here's some info that might help you...

rhododendron

if it is budding but not flowering, it may be that the buds begint to open when it gets warm & then it gets frrezing cold again & kills the buds.

if it is not budding, it may be soil pH or nutrients. do not fertilize with nitrogen rich fertilizer. this will promote foliage & supress flowers. use a high phosphorus fert.

what kind of sunlight are they getting? they need part shade.

they get sun in the morning and shaded in the afternoon

That sounds like a good spot then. Have you tried fertilizing? A couple of years ago, I started fertilizing my rodies both spring and fall with Holly-Tone with tremendous results. My plants are literally covered with blooms and they are so healthy that I don't even have to pick off the spent blossoms any more. Without removing spent blooms, rhododendrons can turn into alternate year bloomers.

Also, plants sometimes need a few years to make good root growth before flowering. Fertilizing will hurry this along.

yes, those sun/shade conditions sound ideal.

i agree with terry - it can take a couple of years for them to become well enough established to start blooming.

some good fertilizer never hurts!

You have got some good advice so far. Whenever people tell me their rhodos are not blooming the amount of light is the first thing I think of.

Since you live in Upstate NY I am going to assume a harsh winter It could be that you have a cultivar or species that is not bud hardy. Check the hardiness rating of the types you used.

I don't know much about rhodies, but I do know that they prefer a more acidic soil. This is probably why there are so many of them out here, tons of fir trees. I've heard you can use coffee grounds as a mulch to increase the acidity, but I've never tried it. Hope any of this helps.