The large ones can get very large, forming a clump up to a metre across and 60cm high with large leaves. They do need space. The small and the medium growers are obviously in between. Hostas come in three basic colours - blue, gold and green, and an abundance of white and yellow variegations on these colours. These may be blue with yellow margin or green with a white margin, or yellow with a green margin or any other combination.
Hosta flowers are all in the blue-lilac colour range except for a few white ones.
Generally they are grown for their foliage rather more than their flowers. The exception is the very fragrant pure white flowers on H.plantaginea which is a delight on a warm summer's evening. There are very few other scented hostas. The keen collector can indulge their interest endlessly with subtle variations. However, we often see people bearing their landscape plans as if they are gospel, searching out the exact hosta named when there are usually varieties which will suffice just as well.