Last year in a small soil filled box which had been used for a vegetable crop many months after the crop had been harvested I noticed some small self sown plants of violas.
How they arrived in the box is debatable.
Anyway this spring I planted four into a window box and they have just started blooming.
They greet me each morning when pulling back the curtains and also every time I come home.
At present I have not cut one bloom and they are giving me enormous pleasure just as they are.