Stratification for Trillium seed?

[GordonT]

I received seed (not moist packed) via the seed exchanges of the following species: Trillium albidum, Trillium chloropetalum (mixed forms) and Pseudotrillium rivale. I would like to do the right thing by them.

My usual routine would be to rehydrate the seed in a soak before planting it. What to do with the seed flats is the main question. Should the pots be kept at room temp for a while before cold stratification? How much cold should the seed pots experience? There is still plenty of snow on the ground here,although daytime high temperatures are trending upward (0 C to 10 C by day, and -5 c to +2 c overnight). I could place the pots outside, or in our cool basement for steady cool temperatures, or in the unheated polytunnel greenhouse (might get too warm during the day).
Any advice would be welcome.

[Susan Band]

My suggestion is rather than use seed trays if you are wanting to try different stratification methods I would put them in ziplock bags with damp perlite. The can then fit in fridges/ house etc. whatever method you use they won't be immediate germinators so you have plenty of time to check them over. When they do start you can see some of them putting out a small root and then you can put them in trays. Good luck

[Herman Mylemans]

I received seed (not moist packed) via the seed exchanges of the following species: Trillium albidum, Trillium chloropetalum (mixed forms) and Pseudotrillium rivale. I would like to do the right thing by them.

My usual routine would be to rehydrate the seed in a soak before planting it. What to do with the seed flats is the main question. Should the pots be kept at room temp for a while before cold stratification? How much cold should the seed pots experience? There is still plenty of snow on the ground here,although daytime high temperatures are trending upward (0 C to 10 C by day, and -5 c to +2 c overnight). I could place the pots outside, or in our cool basement for steady cool temperatures, or in the unheated polytunnel greenhouse (might get too warm during the day).
Any advice would be welcome.

Gordon, there is an interesting article for you on internet "Germination of Dry Trillium Seed, by John Gyer" https://www.nargs.org/sites/default/files/free-rgq-downloads/VOL_57_NO_1.pdf
Good luck with sowing Trilliums

[Carolyn]

Gordon,
I always soak any dry trillium seeds for 24 hrs before sowing, then the pots are placed outside with no protection until germination - no protection, that is, except a piece of horticultural fleece tied over the top of the pot.  This keeps out marauding mice, birds, weed seeds and to a certain extent liverwort. I find that germination can take anything from a year up to several years.  I keep the pots for as long as I can tolerate the liverwort build-up! Here are some photos of recent germinations:
1. Trillium rivale, sown Jan 2014, germinated Mar 2015
2. Trillium rivale, sown Jan 2014, one seed germinated later that spring and more germinated Mar 2015.  I was amazed to have a seed germinate so quickly after dry storage - I have read that fresh trillium seed will sometimes germinate immediately if sown very fresh, but I have never observed this myself. The larger leaf in this photo is the one which is in its second season.
3. Trillium pusillum, sown fresh in Aug 2013 and germinating Apr 2015.
4. Trillium rugelii, sown Feb 2013, germinating Apr 2015.
I could also show you rather a large collection of pots awaiting germination, but I don't want to discourage you!