Great pics, Lin. Yours show up much better than mine do, as mine are so entangled in the 'jungle' out there! I did have this smaller one that has really 'propped' itself up with its prop roots. Some of them are wrapped around the stem, too.
I agree, the half-barrel sounds like a good interim solution, before you go to all the trouble of planting it permanently. Might as well find out if the plant will tolerate and adapt to the weather, location and other factors first. They're such resiliant plants, it probably won't die on you, but it might end up looking so ratty you'd wish it would. Much better chance of keeping it pretty in a pot.
If/when you do plant in the ground, Dawg, I'd amend very generously with loose humus-y compost and then as Lin says use a generous mulch to keep the area moist and keep your clay from compacting as well. You'll have to amend on at least a yearly basis - top dress with a couple wheelbarrows of compost or that kind of stuff, and of course if you have a tree that loses its leaves, collect them up and mulch that plant with them, too. You're trying to duplicate as much as possible the natural environment where these Philos grow, and that is in semi-trop to tropical forests where the soil is loose, leafy duff. Clay soil and low humidity are your enemies as far as this plant is concerned.
