>In the literature, especially the rock garden literature, there are >articles (some of which read like calculus puzzles and kept me tied in >knots) discussing drainage. To make a long story short, I think it's >largely bunk as far as most summer dormant plants are concerned. It's complete bunk as far as anything having to do with plants is concerned, but seems to have some relevance growing plants in wet-winter climates. (I have the Deno quote about "drainage" right here on the laptop but am too lazy to include it.) As far as I know, onco species like Iris iberica, paradoxa, barnumae, etc., grow in climates almost identical to mine. I get a little more rain in July and August than do, say, Erzurum and Van. I suspect that the rain is delivered to the plants there as it is here, by thunderstorms, and all at once. The soil here never stays wet; it never rains all day, and it never rains in winter. (The only all-day precipitation we get here is in the form of snow, like today.) Nothing happens to the dormant irises here if they are rained on. The plants don't need any kind of protection (except from rabbits) or special cultivation techniques. Growth in spring starts after the snow melts, with occasional rain and hail precipitation "events". The hail sometimes destroys flower buds, which is extremely annoying. (Understatement.) Bob Nold Denver, Colorado