Hi everyone. So last night at HD I was browsing around and picked up a few things. A small 'August Beauty' Gardenia and this very pretty Hydrangea!!!! It's called a 'Show Stopper' I'm really excited because I killed about 6 Hydrangeas last year when I was an extreme rookie and had NO clue!!!! I bought a little limelight hydrangea that's doing AWESOME and well I wanted to try my almost green thumb at a regular Hydrangea. This one is labeled as a Hydrangea Marcrophylla 'Show Stopper' I want to pot this hydrangea which by the way is currently in a 2 gallon pot. I do not want to put it in the ground because #1 my soil is horrible, meaning, lots of rocks, etc which I'm currently amending it now but I know will take some time. #2 I want to establish the plant first before I do put it in the ground since I've read here on GW that many Hydrangeas come from green houses which are forced to bloom and therefore sale in big box stores. So, my plan was to put it in a pot, but I don't know what size pot to use. So some suggestions would be great. 2nd question would be what soil do I use? I prefer organic and wanted to actually make my own with:
1 part coco noir, 1 part compost, 1 part perlite & 1 part peat humus ( adding some bloodmeal for nutrients)
I'm still a newbie so I would love some help in making sure

I do not want to kill this one. It looks like it's about 1-2 years old from the size of it and it looks like it's going to start blooming. (I'm pretty sure that's a bud) Do I cut off the current flower on it? I've read somewhere you want to cut off the flowers when you first get a hydrangea and I'm going to assume this is to establish some good roots. Given this is an established hydrangea do I still cut off the flower?
thanks!!
Elce