I used to have violas in one of my containers. I think I bought about 5 little seedlings from Home Depot and have planted them first with my schefflera in Nov 2010:
I thought it will start to dwindle come winter time, but it was a rainy winter season then, it loved the rain and come end of March 2011 it grew this much:
I had to move the schefflera coz it was being overwhelmed by the violas and in its place I have put our lavender anouk in june 2011. I did not know what happened to the violas afterwards, as I had emergency travel back home which lasted the whole summer..I think the plants got fried by the summer heat and my hubby tried his best. And so far it did not return..I was hoping there could be some little seeds left on the container. But then again our winter this year was really very mild and drier.