Mary Sue: I did give mine bottom heat for a couple of growing seasons. I attributed the slow growth to my inexperience with Clivias. I kept them under HID lights for a number of years until they bulked up. I have two plants and a friend has one he has on the floor of a sun room that flowered last year. He knows nothing of Clivias let alone a C. 'Vico Yellow'. You can imagine how I felt when he emailed an image of his plant flowering and mine had not! Arnold