I am in Pennsylvania, but there are a number of people in your area growing rhododendrons. The areas in the Red River valley and the Mississippi valley are probably hotter and more of a challenge for rhododendrons but OK for some azaleas. However the hills in between would be suitable for a number of varieties of rhododendrons, especially the R. hyperythrum hybrids that were bred for the Southern US. The American Rhododendron Society has a list of rhododendrons that do well in Arkansas at
http://rhododendron.org/alphalist1.asp?PP=OZ. This list includes some very hardy varieties that do well in both heat and cold. The ARS also has a Rhododendron of the Year program that has a South Central section that should include your area at: http://rhododendron.org/roy15sc.htm. If you look at the bottom of the page, you can see the selections for previous years dating back over 10 years. I would guess the earlier selections are the more obvious choices and the more recent are perhaps more marginal. In any case, there are people near you growing rhododendrons. They probably are using very good drainage since root rot thrives in hot areas, and some "high shade" to cut the impact of the summer sun. Three varieties have the unique characteristic of being Heat & Cold and Sun & Shade Tolerant: Boule de Neige, Nova Zembla and most PJM varieties. One hyperythrum hybrid that has proven reliable in your area is Peppermint Twist:

Peppermint Twist – 4', -15F. It has red buds, opening to rose pink flowers, with red flecks in the throat and a white circle in the throat that slowly grows larger each day. Just as attractive as the flowers is the glossy dark green foliage, that is held for three years on a vigorous, but compact, plant.

Good Luck!

I can state that in NW Arkansas (near Fayetteville), rhodos aren't usually grown. I had a Nova Zembla once for about ten years, it did really well for perhaps four or five, then went into decline and died over the next few years.
I'm inclined to believe a root pathogen alluded to above during the heat of summer.
There *are* native evergreen rhodos as far south as Georgia, botanically, those that are decidious called 'azaleas' are hardier...and you might want to look at those instead. Azaleas do quite well in NW Arkansas and indeed three species are native to the area.

Thank you so much! I am from the west coast and have missed my familiar Rhodos after 5 years in the prairies. So I was hoping I could get away with it in AR! Rhodyman: Your detailed reply is very helpful especially after asking at 3 different nurseries and having no luck. Dbarron: Perhaps I will try a large tub to control drainage issues better? They have azaleas all around here so I was determined that a rhodo could do well too! Cheers

We had an American Rhododendron Society convention in Tulsa and ARS members from eastern Oklahoma, eastern Texas and Arkansas were there. They are doing especially well with the Southgate and other Thornton hyperythrum hybrids like Peppermint Twist. Retired veterinarian and longtime plant breeder Dr. John Thornton of Franklinton, La. is the person who created the Southgate and other
hyperythrum hybrids that are doing well in the south.

I am sorry, but I don't understand how a large tub would improve drainage.

The conventional technique is a raised mound. Also, to keep root temperatures down to help prevent root rot, a good mulch layer is very important. The combination of a good acidic soil, a raised mound, a good mulch layer, and high shade would be the best bet, and then choose varieties that have proven to be heat resistant. The first time I met someone from east Texas growing rhododendrons I quizzed them about what did well and they were using the hardy iron clads like Nova Zembla. Now with the many hyperythrum hybrids, there is bigger choice. Unfortunately, most hyperythrum hybrids are white to pink. Peppermint Twist is the most colorful. Thornton is working with Steve Krebs at Holden Arboretum in Ohio to produce some hyperythrum hybrids that have more color. Steve Krebs had some at Holden Arboretum during last years convention in Ohio that were spectacular. I understand that Thronton will be releasing some of these soon.

Some nurseries that carry the Southgate rhododendrons include:

Greenleaf Pike Rarefind Transplant

Rhodyman: I thought I could perhaps better control drainage in a tub (with lots of gravel) BUT now that you mention the raised mound idea that sounds better! I would like to do a raised berm landscape in one well sheltered area of the yard, so that may be a good opportunity to try a plant ...or 2. The soil is very clay-like, but so was our west coast soil and they didn't seem to mind as we had rhodos, azaleas and the like. Perhaps it was the high peat content they liked that supplied the acidic soil necessary?

You need to modify the clay to get good drainage. In a raised bed it is ideal to use a good acidic top soil to raise the bed. When I planted in a moist area in my yard, I just dumped bags of Peat Humous on top of the ground and planted in these mounds. I am using Southgate plants there and it is working well.

rhodyman: I've done a search of Nurseries who sell "Peppermint Twist" and no luck so far. The 4 nurseries you mentioned above don't have them either. It seems to be a tricky one to locate!

"Perhaps I will try a large tub to control drainage issues better?"
It doesn't really work that way...too much to go into.

Raised bed...don't overcomplicate it, too many things an amateur could go wrong with IMHO. Just take your native soil, as long as its acid, and mound it up, slighty, in a certain area. If it isn't acid enough, well, there are other threads here about dealing with that.

Just grow any of the hyperythrum hybrids, whether southgate or not. If necessary, call Rarefind and ask which they have in stock. I wouldn't even mess with anything non-hyperythrum derived, like Nova Zembla.