Chris wrote: >>do I get a follow up question? As many as you want. >> How deep Calochortus roots tend to extend below the bulb (esp for the various Mariposas)? Good question. I've never had the courage to dig one up while in growth and check. >>How deep should I plan for the bulbs themselves to dig? I grow them only in pots, and never tried to dig them in the wild. But I remember seeing anecdotes from some of the old bulb-collectors that talked about following bulb cases down and down and down... When I grow them in pots, they seem to go down 1-2 inches every year, meaning I have to repot after two years or they'll be at risk of running into the bottom of the pot (after which they usually die). I've never been sure if they dive deep because they're looking for cooler soil in an overheated pot or just because it's in their nature to move down. Personally, I'd try an experiment in which you put a layer of about 6-8 inches of your planting mix above the local adobe. I know that's enough depth to keep the bulbs safe from rot for a couple of years, and with luck the roots will be able to reach the moister soil. Then after about three years dig them up to see how far down they've gone, and if any are in the clay. I'm not sure that growing into the clay would hurt them, as long as it's far enough down that it won't get hot. But I think the biggest issue isn't the depth of the planting mix, it's keeping up the watering until the seed pods are mature. >>If they reach a water-retentive layer, will they tend to stop digging, or will they dig into it and potentially rot? Unfortunately, I don't know. Sorry. By the way, perlite is going to make your soil mix even more fast-draining, unless the perlite is full of fines. Mike San Jose, CA