CAMPANULA Campanulas are a major element in the summer garden; the genus displays great diversity in size and form providing everything from tiny trough species to huge gaudy border perennials. Admittedly the color range isn't much, most are blue with the attendant albino versions, and what passes for pink or yellow is pretty pathetic, still how can you go wrong with blues and purples, at their best they rival the finest gentians in terms of color. Most are easy and free blooming, producing a spectacular display in the garden. For the rock gardener there are species that will test the patience of even the most skilful grower. Campanulas are an indispensable group of plants that can keep your interest for years; for as long as I have known her Betty Blake has been busy growing every species Crook lists, not to mention all the new ones. The list below should give you a fair start on her quest.