Roots. What do I do please?

Yo!
I bought 2 roots (about a month or more back). They are called Incarvillia delavayi.
I stuck em both in the soil, but wasn't sure how deep. Should I have left the top above the soil, or completely covered them both? Nothing has happened?
They looked like brown carrots! :( so I stuck them in skinny bit down. ???
I also buried some lillies (asiatic). I was told to put them 5cm down, but surprisingly they have shot up through the soil and look like bud type things now.
I am very pleased with those

 

Thanks for the reply dude. The lillies were like bulbs with a bud at the top. They are in a garden pot thingy. They have surfaced and look sweet so far (pic attached).
It's the incarvillea I am more concerned with. I will take a pic of one of those too the stick is pointing at it