Hosta Katherine Lewis will form a medium sized clump of 16"-24" in height,with a spread of up to 36", at maturity. What a lovely Hosta, Katherine Lewis is. Apparently it is a sport of a seedling of Halcyon. Overall it forms a clump with thick leaves, that emerge almost entirely blue, and as the summer wears on it gradually develops a bright gold centre, which of course will be brighter in lighter positions. It produces long 30" scapes with pale lavender flower atop, in summer.  It is a very good grower, and I recommend it. It is also slug resistant and will tolerate some sun, particularly early morning.