Trilliums from seed

[shelagh]

All forumists will know  that I am not one of the best at retaining info, but stuck in my mind (probably via Diane Clement) was that when you sow Trilliums put a label in saying keep for 2 years because the first year they do their thing underground.  I was astounded when Brian brought in a pot of our own seed which I sowed in August 2016 and they're all coming up. What's happening, have I got it wrong or does it depend which Trillium it is?

I will do my best to remember what you tell me

[Carolyn]

I find that sometimes, but not always, when sowing very fresh seed that it will germinate in the following spring. I think some triilliums are easier to germinate than others - I seem to have several pots of ungerminated T. erectum lying about! I had a look at my trillium seeds from last year's seedex, soaked overnight and sown in late January. I soaked these briefly in GA3. There are signs of germination in T. maculatum, rivale and cuneatum. I don't give up on trillium seed for 5 or 6 years at least.
I wonder whether fresh seed germinates rapidly if there is a bit of warmth after it is sown, before winter sets in. Last summer I sowed several pots of T hibbersonii and left them in the greenhouse till October to keep them warm. Other pots were placed straight outside. I will try to find these tomorrow and report back if there are any signs of growth.

[Gabriela]

It seems that there are big differences between various Trillium species regarding germination. Even more, there are differences in between various populations of the same species.

I can only give precise examples for T. grandiflorum and T. erectum that I collect and keep moist right away after collecting (at warm until October then I place in cold storage). Depending on the locality/ populations, there can be 60% or more seeds germinated (rhizome only) by October (coll. in mid July usually in Ontario). The germination is random in seeds of the same provenience.

If placed at cold in Oct. by Jan. some can start expanding the cotyledons, but some will remain in the stage with cotyledonary tube attached to the seeds till spring - see image.

[Leena]

I will write in this old thread, because there is talk about the same thing I'm writing about.
I have now been lucky to sow fresh seeds from my own plants in two years. The seeds ripen here in late August/early September, and then I put them in moist vermiculite in a zip log bag and keep warm about 18-20C. Last year the seeds started to form root (or rhizome) in late December, about four months in warm, at which time I potted the seeds and put the pots in cold stratification. They then germinated well (formed first leaf) four months later in early May.
Last autumn I did the same, and again four months later in early January there were roots and now seeds are in cold and hopefully germinate in the spring.
These Trilliums were T.chloropetalum and T.kurabayashii (and this year I got fresh seeds of T.cuneatum which also did the same), but I also had my own fresh seeds of T.erectum, which did not form root in that time in room temperature, or germinate yet.

I have been thinking if could there be differences in the temperature requirement of different species for this warm period. For peonies some species need +20C to form the root, and some only +10 (and they don't break the dormancy in higher temperaturea). Can there be something like that also for Trilliums?

[Catwheazle]

< For peonies some species need +20C to form the root, and some only +10

Hi Leena,
do you (or someone else here) know, which peonies need "only +10°"

thx and greetings
Bernd

[Leena]

< For peonies some species need +20C to form the root, and some only +10
Hi Leena,
do you (or someone else here) know, which peonies need "only +10°"

In my experience P.officinalis and it's relatives germinate best in temperatures +10 -12C (not in room temperature), and also P.obovata may need lower temperatures than P.lactiflora.

[Catwheazle]

 Interesting   
Thanks for the Info.

Bernd

[Carolyn]

Leena, an interesting observation. My trillium seeds are usually ripe in July or August, depending on species, and sometimes I have had rhizomes formed during the first winter and leaves in spring - but not always. I leave the pots outside, unprotected from the weather. They certainly do not get 4 months of 18 - 20C in late summer/autumn (or indeed at any season in Scotland!)
I think I will try your method and see if it gives faster results. By the way, I find T. erectum germination can be very slow or fail completely!

[Leena]

Carolyn, thanks for your experience. I don't know what the temperature for rhizome formation should be, 18-20C just happened to be what it was, but maybe lower temperatures also work like your wrote.
Here cold comes too early, and I haven't tried them outside at all, it may be only a month after seed ripening to the frosty nights and very low day temperatures. The only Trillium which I have managed to sow outside and have germination in the first spring, is T.nivale, but its seeds ripen already in early July, so they have a lot more time before autumn, at least two hotter months with temperatures close or above 20C and even September can be 10-20C here. October is usually below 10C.

I just thought to write about this, because earlier I had thought that Trilliums always need two cycles of seasons and germinate only the second spring.

By the way, I find T. erectum germination can be very slow or fail completely!

This is good to know! Also for me T.chloropetalum has been better to germinate than T.erectum, even from dry seeds.

[Catwheazle]

How are your experiences with Trillium camschatcense? Here (= Allgäu, mountains, approx 1000NN sometimes snow in June) I brought them to "survive",
but they always have to fight with late frosts. This year I'm confident of getting seeds for the second time and I don't want to go wrong.

[Carolyn]

How are your experiences with Trillium camschatcense? Here (= Allgäu, mountains, approx 1000NN sometimes snow in June) I brought them to "survive",
but they always have to fight with late frosts. This year I'm confident of getting seeds for the second time and I don't want to go wrong.

I once bought fresh seeds of this from Yuzawa Engei in Japan and I have waited 5 years.... still no germination!

[Catwheazle]

 

[Lesley Cox]

In my (somewhat limited) experience, the larger-growing the species of Trillium, the longer it takes to germinate. But that's a very inconsistent judgement. For me the only species which germinates regularly and early (as if it were an iris or anything else bulbous) is T. rivale. All the others take from 2 to 8(!) years and the longer times are usually for the big species such as chloropetalum, though angustifolium takes only 18 months or so if the seed is reasonably fresh at sowing. My friend Dave Toole who grows many trilliums of all kinds, and who lives in a mild but damp climate, (bottom of the South Island of New Zealand) is the genius with Trillium seed and I think has posted about it on the Forum previously. At any time he has many pots of seed and seedlings and I think they also grow in his pockets, up his sleeves and in his moustache and hair as well as in pots in the open and in his shade house. He always has thousands on the go. He does have various timings which he applies but even so, the seeds come through for him regardless of time, season, weather.

Overall, freshness is probably the key and for me, I simply sow as soon as they ripen or as soon as I  obtain them then wait and hope. 
 

[Rick R.]

My experience with Tt. cuneatum, a sessile hybrid, and kurabayshii mimic yours, Leena, when I have them inside.  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.  I do have T. cuneatum and the sessile hybrid that reseed spontaneously in the garden.  I was quite surprised when I first spotted the seedlings.  I didn't think the area would be very conducive for their growth.

Trillium sessile hybrid:


Trillium cuneatum:

[Leena]

Rick, thanks for confirming my experience with inside growing. My experiece is still so limited and short, and I don't have any Trilliums yet germinating outside though I know some seeds which had escaped from seed pods before I could get to them:).

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.

How are your experiences with Trillium camschatcense? .

I have sown once 2014 dry seeds from Holubeck, and they never germinated. I think I have unfortunately discarded that pot now, will have to check in the spring.