i have a pot with lobelia which i grew from seed. It looks healthy but is not flowering. I asked a guy at farmer's market who was selling lovely lobelia baskets and he suggested i use some fertilizer. i added some Osmocote but still no flowers. It looks beautiful but i wish it could flower as well. The leaves were green but they have turned purple since i put it in sun. The change was only color and the plant remains healthy.
Below are few pictures :
It was green when it was in shade:
Kept it in sun and leaves started turning purple:
This is how it looks after couple of weeks in sun: