Thanks Mike. I will test your drying-out theory this year. Everything you read about Calochortuses tells you to make sure the mix is well-draining, and I have only ever seen them in the wild growing in very well-draining situations, so I may well have overdone it. (Coincidentally John Wickham had the same thought about them succumbing to a dry spell, and a similar suggestion how to address it.) So, this season I will try a water-retentive layer below the bulbs, at a depth where the roots can reach. The question is how deep. Protocol ... do I get a follow up question? (Sorry I’m new here.) Might anyone provide me some guidance re: a) How deep Calochortus roots tend to extend below the bulb (esp for the various Mariposas)? In other words, how deep a water-retentive layer should I make? b) How deep should I plan for the bulbs themselves to dig? I forget which species dig in more than others, but I recall some of them pull themselves deeper each season. Does that mean a bulb could sit 20” or more below the surface and still bloom? If they reach a water-retentive layer, will they tend to stop digging, or will they dig into it and potentially rot? Finally regarding the other potential causes Mike and Jane raised: - I appreciate Jane’s caution against chlorinated water, a concern in LA. (The tap water reeks of chlorine, at least in summer). However, my plants are watered from a fish pond, so this shouldn’t be an issue. - Didn’t notice any infestations or pollen-eating beatles but will keep an eye out. - Inbreeding? That might once have been an issue (eg, where I had only a single bulb of a species), but I think I have genetic diversity for everything now. Regards, Chris. On Thu, Aug 15, 2013 at 10:47 AM, Michael Mace <michaelcmace@gmail.com>wrote: > Chris wrote: > > >> A capsule develops (sometimes to full size) but stops developing before > the seed matures. I am wondering if this is common > > I'm not really an expert, but I have some experience, so let me speculate. > > In my experience it's not common for Calochortus to abort their seed pods > like this when the bulbs are completely happy. > > I've seen Calochortus bulbs in pots abort their pods when the pot dries out > a little early while the seeds are maturing (for example, I had that happen > this season with one pot of C. argillosus that was in full sun). What seems > to happen is that if the pot dries out too much while the seeds are > developing, the bulbs immediately stop putting energy into the pods. They > just stop growing. They'll dry out, but they never open and often the seeds > inside are not mature when you open the pod. > > I'm just speculating here, but I wonder if maybe your soil is drying out > too > much during the seed maturation process. In nature, many Calochortus grow > in > the ground in decomposed serpentine that can be surprisingly > water-retentive. I tried putting some of that soil in pots once, in an > effort to grow some rare Calochortus species. The soil stayed completely > goopy and waterlogged all winter, and then turned into a concrete-like > substance in the summer. > > Even though your plants are in the ground, the adobe underneath them may be > so deep that the plants can't reach it to draw on it as a water reservoir. > So they're growing exclusively in the planting mix you created, and maybe > that's drying out too fast. I grew up in LA, and I can imagine the full sun > and low humidity sucking all the moisture out of your planting mix. > > You could try a couple of experiments if you want: > > --Create a different part of your planting bed with the adobe only about > six > inches below the surface, so the bulbs can reach into that for moisture. > > --Try watering one section of your growing area a few times as the seed > pods > are maturing. In my experience, Calochortus bulbs are not too vulnerable to > rot from watering if they're still partially in growth. The time you really > don't want to water them is when they're totally dried out and brown, even > down to the stems. > > Two other possibilities to think about: In California there are many small > beetles adapted to eating the pollen of Calochortus. They go along the > anthers like they're ears of corn, and strip off all the pollen. I've had > some plants stripped so thoroughly that they can't set seed. So you might > want to try some hand pollination. > > The other question to ask is whether you're sure that you have genetically > different individuals of each species. I find it harder (but not > impossible) > to get seeds from a single self-pollinated plant than from several > individuals crossed together. If you got your bulbs from one of the mass > market bulb companies, they might all be genetically identical clones. > > Hope this helps. > > Mike > San Jose, CA > > > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >