As nearly as I can judge, the English get their great and glorious mass effects from only six or seven groups of rock plants. I think they depend chiefly on the saxifrages for white and for lacelike effects; on the rock roses, or helianthemums, for a wide range of colour; on the sun roses or cistuses for large individual blooms; on gentians for blues; on primroses for yellows and crimsons; on the purple rock-cress, or aubrietia, for big carpets of bloom cheaply raised from seed; and on the pinks for fragrance.
All of these we can grow on a good rockery, but I believe it is folly for us to try to get great landscape or garden effects with any of these plants, save pinks. I am confident that we shall get equally gorgeous effects, but with a different set of plants. And I know we have done wrong in making a big fuss about the few plants which we cannot grow as well as England, instead of trying to see how we can get just as big effects that shall be distinctly American.