Encouraging Calochortus to Set Seed

Giant Coreopsis giantcoreopsis@gmail.com
Fri, 16 Aug 2013 16:37:41 PDT
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

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
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