Calochortus are usually grown in containers in Britain, say, or occasionally in a corner of a "xeriscape" in drier climates (there are some high mountain species I suspect would do just fine in a sunny rock garden anywhere, but they are the exception...).
My garden is over a half acre: too big to try and irrigate in our semiarid climate. So half the garden grows largely on what does (or doesn't) fall from the sky. I have a small meadow planted mostly to blue gramma grass (Bouteloua gracilis), the shortgrass that probably would have been on my garden prior to disturbance. Five or six years ago I purchased several hundred bulbs (they were ridiculously cheap at the time, like $.25 apiece!) of four species of Calochortus from Brent and Becky's bulbs. Cc. luteus, venustus and speciosus all went into this meadow. I'd scattered several hundred seed of Calochortus gunnisonii I'd had sitting in my seed files for years as well. It took several years for the gunnisonii to come into bloom: I now have dozens of these as well: the original Californians have taken well to their Colorado captivity. The second shot shows these last summer blazing away. I now look forward to seeing what permutations show up: some of the original clumps have five or more stems, and a dozen flowers this year! Can't wait till May when they bloom again!