[kindredspirit]

They look good and the burnished red/brown colour will complement the green of plants.

[Good guy]

Yes. They are unglazed, but they are made from a stoneware clay and have been fired, at a guess to well in excess of 1200 degrees C. The burnished sheen is a result of fly ash (probably from wood) acting as a flux on the silica in the clay - the large amount of iron oxide in the clay would help in this.

[Greengage]

Nice job well done. Suggestions for the pots, Camelias, Magnolia soulangeana,Box, Olive tree (Maybe not in Donegal), Banana, Citrus, Phormium, Agave,Lavanders, brugmansia suaveolens.

[Good guy]

Thanks, Greengage. I'm also thinking of smaller azaleas, rhodos. Not sure yet whether to go for one permanent plant around which I can put short-lived ones or annuals or whether to treat the whole thing as a 'changeable feast'.

Whatever I go for, if a permanent plant it will need to be hardy. No way I'm moving that pot when it's full!

[Greengage]

There are Rhodos which are lime tolerant and grow in poor conditions, i think they are called Cunningham White gtrafted onInkarho rootstock, Ill have a look see....
Found a reference to it.
http://www.telegraph.co.uk/gardening/6581138/The-new-lime-tolerant-rhododendrons.html
The Inkarho rootstock has taken a good 20 years to develop. Its story began when a self-seeded rhododendron was spotted growing in a quarry with a known limey soil and bedrock. This then was bred with R. 'Cunningham’s White’. The resulting progeny of about 20,000 seedlings were grown on and eventually the growers chose the Inkarho. Many factors apart from lime tolerance would be important in this choice: bushy habit, vigour, uniformity and good grafting ability to name a few. This extensive work has been done in Germany by a consortium of about 20 large nurseries. Several British nurseries are now importing the plants. About 40 different rhododendrons are on the market in a range of popular colours, which, it is claimed, can be grown in a far wider range of soils than rhododendrons will usually tolerate.

[Good guy]

That's a very interesting article, Greengage, I'll keep an eye out for them. I've no problem growing rhodos here, on my soil, except when builders' rubble intrudes! But some of the plants shown look stunning and worth a try.

[kindredspirit]

There's a load of Inkarho Rhododendrons planted a couple of years ago in Blarney Castle Gardens in soil under which there is Limestone Bedrock. They're doing well, apparently.

[Good guy]

I'm just remembering the thickets of rhododendrons in the woods of Florencecourt castle where I used to wander as a young lad (since largely cleared by the National Trust). That is close to Marble Arch caves and much of the local stone is limestone around there. There is sandstone, too, so maybe that underlies the rhodies.
I often used to walk past the Florencecourt Yew - source, I believe, of our fastigiate Irish Yew.

[Sue Deacon]

In Austria there is a rhodo, known as the Alpenrose (Rhododendron ferrugineum) it grows in about 6" of peaty soil on a bedrock of Limestone, nice - just like everything else in Austria.