I received packets of seed for Calochortus bruneaunis and Calochortus leichtllinii during the surplus round, and am wondering how to handle them. Lately, overnight temperatures have settled either side of freezing, with daytime highs forecast to range between 41 and 50 F for the next two weeks.
Calochortus seeds are totally new to me, and I couldn't find much information about a germination protocol for them. Do they require stratification? I figure I have three options:
1 Sow immediately in a gritty mix, and expose to the elements (they may not get enough of a chill to germinate)
2 Toss the seed and some lightly moistened vermiculite in a ziplock bag and refrigerate for a period (how many weeks?) then sow once the seeds germinate.
3 Refrigerate the seed packets in a ziplock bag, and wait till autumn to sow them, placing the pots in an unheated greenhouse for the winter.
What would give me the best chance at success?
Put the seeds in a freezer
Put the seeds in a freezer bag with some fine, damp sand (sand like "play sand" obtainable at home improvement stores), and leave the bags in the refrigerator (not the freezer) for about four weeks. After that, the emerging embryos should be visible with a 10x lens. You can then sow the entire bag of seeds, or just the ones which are germinating. (The seeds often don't all germinate at once.)
The seed can be sown in pots, on top of a soil-less mix, the seeds one-quarter to half an inch deep. (.6 to 1.25cm) You will see seedlings emerge within a couple of days.
That's the easy part.
Once the seedlings have germinated, the seed pots need to be moist, if not soaking wet. The tip of the seedling will register any unhappiness first with browning or yellowing, followed by death. After a few months, if the seedlings aren't already dead, the tips will start to yellow, and this is a sign that it's time to let the pots dry out.
At this point, I would plant them out in the garden (and wait for rabbits to devour the emerging foliage next spring), but that depends on the climate in which the bulbs are to be grown.
Here is a photo of seed of
Here is a photo of seed of Calochortus nuttallii germinating, using method described above.
I had gotten a lot of Calochortus seed last year(2013) in the surplus round, too. I had decided just to futz with the seeds and experiment a little. Not sure this will help much, but this is a good place to show some unscientific results.
We had an unusually cool April, and into May last year when I planted these seeds from the NARGS seedex.
species/number of seeds/date planted o=outside/date emerged, number of seedlings, a=uniform emergence
Calochortus barbatus 16s
Calochortus catalinae 7s
Calochortus concolor 11s
Calochortus howellii 13s
Calochortus obispoensis 14s
Calochortus splendens 14s
Calochortus superbus 10s
Calochortus uniflorus 8s
Calochortus venustus mix 13s
Calochortus venustus 14s