Trilliums from seed

[Leena]

Although, at the end of the warm treatment, the temp does go down to about 15C, just because it is cooler in the winterl where I have kept them. 

Maybe this is what is needed, in autumn the temperatures drop in the nature too. Maybe this can also affect the root/rhizome formation??

[Véronique Macrelle]

therefore, if sowing from dry seeds, the pots should not be thrown out for 7 years.
i start to have a collection of pots on hold..only in the long run, the earth settles.
luckily, I also received some fresh seeds last summer and I have hope for this spring: I am waiting for you to tell me when the first leaves come out, to go and visit them one by one. the problem is that these old seedling pots, I tend to lose interest in them, and you have to keep watering them.

 this year I believe it!

It is only with you that I can talk about these seeds that take too long to germinate and my stubbornness in sowing them: elsewhere, I would be taken for crazy ...

[Maggi Young]

After  a  few  years old pots of ungerminated seedlings  can get  tossed on the  border  soil - and  that can lead  to some  nice  surprises in coming years as recalcitrant  seeds  finally  decide to grow!!  And yes, Véronique, we're  all crazy! But  in a  good way! 

[Gabriela]

Maybe this is what is needed, in autumn the temperatures drop in the nature too. Maybe this can also affect the root/rhizome formation??

I strongly believe Leena that the fluctuations in outdoors temp. have an influence on the dormancy release of various seeds, and not only for Trillium. I also mean the fluctuations from day to night temp. which are more pronounced in late fall.
Reason why, by sowing and keeping the pots outdoors sometimes leads to different results than when providing stratification in the house/fridge at constant temp.

Trillium wise: Trillium erectum always germinates mainly in the second year, even when sown fresh. Maybe there is not enough time for its warm period in the first season. or who knows...The seeds here mature in August.

This year I will be able to add more knowledge for T. luteum germination: for two years in a row when I obtained only one capsule with few seeds, I planted them right away outdoors and they always germinated promptly in the spring (seeds mature in mid August here).
Last year when I had more seeds for the first time I also stratified them in a bag and kept them in the house: room temp. and since late Nov. to cold. None of the seeds have formed rhizomes to this day.
It will be interesting to see how they will evolve as the spring approaches.

[Leena]

And yes, Véronique, we're  all crazy! But  in a  good way! 

I agree!

I strongly believe Leena that the fluctuations in outdoors temp. have an influence on the dormancy release of various seeds, and not only for Trillium. I also mean the fluctuations from day to night temp. which are more pronounced in late fall.
Reason why, by sowing and keeping the pots outdoors sometimes leads to different results than when providing stratification in the house/fridge at constant temp.

Last year when I had more seeds for the first time I also stratified them in a bag and kept them in the house: room temp. and since late Nov. to cold. None of the seeds have formed rhizomes to this day.
It will be interesting to see how they will evolve as the spring approaches.

Gabriela, thanks for your thoughts, and I agree about the fluctuation. Some seeds germinate better when they are  outdoors (under snow) over winter even here. Mostly I think especially Ranunculacea are better sown that way, and even so they may take two years. I'm just impatient to get more Trillium plants, and that is why I use the ziplog method:), and it seems to work at least for some species. Maybe T.erectum needs different conditions than some other species.

T.luteum: I got seeds in early October last year, soaked them overnight and put in vermiculite in ziplog bag Oct 3rd, and bag was kept inside. In Jan 26 I had sowed the seeds in a pot and put it in the cellar for cold stratification. I had written in my notebook, that there were good roots(rhizome) at that time ( I had also some other T seeds without roots which I potted anyway, one of them T.erectum), but I don't know if all the T.luteum seeds had roots. Anyway, I will see in May how they will come up.

[Carolyn]

[quote author=Leena link=topic=15015.msg418486#msg418486 date=1612257589

Carolyn, I just remembered that also T.hibbersonii from your fresh seeds germinated the first spring . I sowed the seeds straight to a pot in early summer so I don't know how and when they formed the rhizome, but next spring there were seedlings, the whole potful.
[/quote]

That’s good to hear. It’s a species which does often come up in the first spring, if the seeds are fresh. I think the rhizomes form in late autumn - sometimes I can’t resist having a rummage in the pots to see!
By the way, your hepatica seeds all germinated last spring, so very soon I will be potting them on. Thanks!

[Rick R.]

I certainly do believe that fluctuating temps affect seed development. 

In the case of my trillium seeds inside, noting that the temp difference was only a few degrees at the end, I wonder if that was just a gentle nudge for the seeds. The seeds had already completed their initial stage of development and were just waiting and waiting for a little "encouragement" to go on.  And I propose that a month before, assuming that initial requirement had been met, a larger temperature gradient would have been needed.   I know that with certain Lilium spp., the effect (of the length of this "waiting" for the next development step) can go one of two ways: either increasing or decreasing the impetus strength needed to progress.

For seeds with arils, where insects bury the seeds, how would day and night temperature fluctuations affect these?  If the seeds were buried, say 3 cm underground, is there a day/night temperature fluctuation?  Perhaps exposed to direct daytime sun, but what about shade?

What about trillium seeds that don't get so buried, and just drop from the pod?  These are certainly more exposed to diurnal fluctuations.  I find a lot more evidence of this kind of germination, than seed that is carried away and buried.  In fact for trillium, I haven't found that yet.  (But really, only have 5 years of observations.)

Tangentially:
I didn't realize that Saruma henryi seeds have arils, but I guess they must?  For 15 years I have never found a seedling near the mother plant, but there are many in the sunnier areas 3-4m away.

[Catwheazle]

Great   
Thanks for sharing your observations

[Gabriela]

Gabriela, thanks for your thoughts, and I agree about the fluctuation. Some seeds germinate better when they are  outdoors (under snow) over winter even here. Mostly I think especially Ranunculacea are better sown that way, and even so they may take two years. I'm just impatient to get more Trillium plants, and that is why I use the ziplog method:), and it seems to work at least for some species. Maybe T.erectum needs different conditions than some other species.

T.luteum: I got seeds in early October last year, soaked them overnight and put in vermiculite in ziplog bag Oct 3rd, and bag was kept inside. In Jan 26 I had sowed the seeds in a pot and put it in the cellar for cold stratification. I had written in my notebook, that there were good roots(rhizome) at that time ( I had also some other T seeds without roots which I potted anyway, one of them T.erectum), but I don't know if all the T.luteum seeds had roots. Anyway, I will see in May how they will come up.

The fact that Trillium erectum has a different dormancy than T. grandiflorum can also be observed in the wild populations. While carpets of T. grandiflorum can cover the woodland floor (and I showed pictures), T. erectum only shows up here and there and many times as isolated specimen or a small group (in this  part of Ontario at least).
It is possible to be due to the fact that T. erectum requires mostly a 2 year period for dormancy release while T. grandiflorum has a high percentage of seeds which germinate in the first spring? Hard to say.

I am happy to hear about T. luteum! Were the seeds from me, or another accession?
My seeds were placed in a colder room in late Nov. like I mentioned, so if you kept yours at room temp. until Jan., it means quite a few more weeks at warm.

[Gabriela]

I certainly do believe that fluctuating temps affect seed development. 

For seeds with arils, where insects bury the seeds, how would day and night temperature fluctuations affect these?  If the seeds were buried, say 3 cm underground, is there a day/night temperature fluctuation?  Perhaps exposed to direct daytime sun, but what about shade?

What about trillium seeds that don't get so buried, and just drop from the pod?  These are certainly more exposed to diurnal fluctuations.  I find a lot more evidence of this kind of germination, than seed that is carried away and buried.  In fact for trillium, I haven't found that yet.  (But really, only have 5 years of observations.)

Tangentially:
I didn't realize that Saruma henryi seeds have arils, but I guess they must?  For 15 years I have never found a seedling near the mother plant, but there are many in the sunnier areas 3-4m away.

It is very clear Rick, even if we follow only all the writings about Trillium germination in the forum, that there are differences between species in regards with their needs for dormancy breaking. That's why I think is best to write the species name not just Trillium when we refer to something.

Regarding the seeds with aril which get buried (in general), various studies have shown that many will actually not germinate because they are either too deep in the ground or in unfavorable conditions for germination.

Trillium grandiflorum and T. erectum seeds which may be found sometimes on the woodland floor, will just dry up in this part of ON. Late July and August are pretty hot here.
A percentage of those who are carried away, if not hidden too deep, will manage to germinate. But it will be a tough life for those young seedlings I have to say.
I am in awe every time I see those tiny one leaf seedlings in the woods and wonder how many will reach flowering stage.

Yes, Saruma seeds have arils (just like Asarum) but they dry up very fast and are not visible anymore. Seedlings can appear everywhere in the garden if the conditions are favorable.

[Véronique Macrelle]

How much do you bury your Trillium seeds in the pot?

[Gabriela]

How much do you bury your Trillium seeds in the pot?

I don't particularly pay attention to this, probably 1-1.5 cm; I keep the ratio between the seed size and sowing depth, like for other species.
In the second year there is usually a need to top up the pots with more mix.

[Leena]

By the way, your hepatica seeds all germinated last spring, so very soon I will be potting them on. Thanks!

It is good:). They are just ordinary blue and pink ones but very hardy here, and have formed good clumps in my woodland bed. Much bigger than in the wild.

I am happy to hear about T. luteum! Were the seeds from me, or another accession?
.

They were your seeds:). Thank you again, and hopefully when they flower, there will be also seeds from my lonely one T.luteum, which has never (in 5 years) set seeds:).

[Herman Mylemans]

Very interesting discussion! Between 2014 and 2018 I have been sowing a lot of Trilliums of different sources.
Seeds need to be fresh! If not I put them at least 24 hours  in water and sometimes I used GA3. For me it is a hobby so I don’t need 90% succes. Some Trilliums like grandiflorum, cuneatum, ovatum, erectum, luteum, germinate very easy in our garden in Belgium if I don’t remove the berries it is like weeds. Reasons maybe:
- humusrich soil between shrubs, airy soil on top and deeper heavy soil.
- our winters start late, coldest period mostly Februari most frost.
- fluctuations in temperature periods.
- enough moist during the most of the year
   (the last summers were sometimes to dry, so Trilliums did go early to rest)
In pot for sowing I use a humusrich airy mixture. For lime lovers I put some tufa in the mixture. The seedlings stay in the same pot till they flower. So I use big pots depending on the number of seeds. First I placed the seeds on top, but later I placed them allways around 3 cm deep (ants also move the seeds to a deeper position). Sometimes I saw one leave during the first year, then there were different periods of colder and warmer weather. But mostly one leave appears after two winters. The pots stay in the greenhouse because of troubles with birds (digging in the pots). At flowering stage they go in the garden, always in a group. Enough space (a few meters or more) between the different Trillium species, so the chance on crossings is less. Germination of Asian  Trilliums is mostly very little, I think they like more moist then the American ones.

[Carolyn]

Herman,
Some interesting observations. I remember that after the hard winter of 2010 i had some good germinations.
As for birds digging in pots outside, I put my seed pots in a tray and cover it with horticultural fleece. It keeps out weed seeds, old leaves etc too and offers some protection from slugs and mice.