it needs an acid soil, if you are not sure of your soil then you can get a test kit ( or see if the hydrangeas growing locally are blue-acid or pink-alkaline-- ) that gives you an idea but gardens can vary

I did the same about 3 years ago,and it has done well.My soil isn't acid,but I put lots of ericaceous compost in the hole,plant the pot grown Camelia with as much of its existing soil as you can,so as not to disturb it too much..Plant it to the same level as it is now,and water well,even in the wet weather,to settle it in.They prefer a position that doesn't get early morning sun,so as not to scorch the flowers in the frosty period.north facing is ideal,if possible.Give it a mulch with said compost,and it should be ok. Important to water well all summer,as this is when the buds are forming for next year.You may,of course,not see much bloom the first year,till it gets established.

Thank you very much