Rhodies should grow everywhere in Middle Tennessee as long as they aren't in full sun or sitting in a pool of water.

In my experience some varieties do better here than others. Proven R. catawbiense performers that are pretty easy to find are 'Roseum Elegans', 'English Roseum', 'Chinoides', 'Alba', 'Boursault', 'Nova Zembla' and 'Vulcan'. R. maximum and its hybrids do quite well in middle TN, too. I've heard rumors of wild R. maximum occurring in Hickman Co. If anyone knows where they are, email me!

Why many rhodies fail in this area is due to how they're planted. They DO NOT want to live in heavy wet clay soil. So they must be planted high, in soil significantly amended with pine fines (soil conditioner) or a similar acidic organic substance. Excellent drainage and a high percentage of organic matter is key, as is an acid pH, preferably below 6.

Marty

I'm also interested to learn more about this. Rhododendron is an absolutely huge genus and it shares some of the same issues of other Ericaceous plants. It is possible to find Azalea, Kalmia etc growing wild in and around middle Tennessee but often they are isolated rather than in large stands. Also, the ones I have seen in mTN are typically at elevations of around 900-1000 feet or so. Our warm, humid nights are probably an issue too because they encourage some foliar and fungal problems that many Ericaceae are prone to. In plateau and mountain regions, though days can be as hot or hotter, nights frequently are considerably cooler. Providing proper drainage and consistent moisture can also be challenging, most places except certain microclimates would require some supplemental watering even after the plants are established. Most I have grown and seen have been relatively short lived, but some have been ok for 8 years or more before succumbing and slowly deteriorating.

I would like to learn more about rhododendrons of Turkey and Asia (there are like 700 species or something!), particularly ones that grow at lower altitudes. I'm sure there are some that would tolerate our combination of funky nights and often less than ideal root media and moisture. One red himalayan species we had was spectacular for years but eventually hit the wall. Even the native ones seem to thrive in the mountains but not so much elsewhere. A combination of factors no doubt. If they were easy and long-lived here I would expect to see more old plants around, especially in old or public gardens? Most I've seen in cultivation in middle Tennessee are not decades old. On the other hand, maybe some of the new cultivars we see in landscapes will be around 30 years from now. Does anyone have rhodies in their gardens in mid TN that are decades old?