I bought a Mikado about 3 weeks ago, and it has been doing fine outside. 3 new blooms are growing up, so I feel I've not killed it. My last Mikado, well... I didn't know how to take care of it and neither did the place I originally bought it from.

I need to bring it in the house for the fall in a month or so, and feel I should also repot it in a slightly (not much more) larger pot. What soil type should I use? I've seen a couple of things on the web:

http://www.wildchicken.com/nature/garden/nature_200_140.htm

and that site lists 'Acid compost' but I'm unsure what to use. The soil in the pot does not look like regular potting soil - it is a bit spongey. Also, a green moss has started to grow.

Also... about watering...

I've been watering it from the bottom every couple of days as the soil gets less moist. I haven't let it dry out, and I'm wondering if I can just leave the pot sitting in water, or if that will cause root rot.

There are so few details about this plant, but I really want it to last this time!