Hi. If memory serves me it is not very long. I am new to Trilliums. Just got some last spring and I don't remember them being in flower very long. I would guess a few weeks. But I know there are some Trillium experts around here and they can tell you for sure.

We have many native trillium grandiflorum growing in our woodland, and I have moved some to my garden. For us they emerge while the weather is still cool, in late April-early May, and so they grow more slowly than yours would inside a house. I would say, it takes a week or more for the flowers to emerge after we see the plant coming up. The flowers last for about two weeks. They are white at first, but turn pink as they are dying down. The plants go dormant in later summer, so you may not remember where they are until next spring again. The plants are slow to spread, but if you watch when you are weeding you will find tiny seedlings around the mother plant in a few years. Around here in northern Wisconsin we see woodlands totally carpeted with white when the trilliums are in bloom. Although I grew up in Wisconsin and am past retirement age now, I still get a thrill when I see this every year. Enjoy your trilliums!

Just a suggestion. I grow several species of Trillium, including T. grandiflorum, in large shallow pots(5-6" deep), as well as in the garden. When the seed mature, they fall into the pots and germinate. It's easier to find and remove them to their own pot once true leaves emerge.
Rb

Thanks for the info and helpful hints. The sepals just 'popped out' today. These little fellows are real keeners.

I would have thought they'd spread mostly by rhizomes but I appreciate knowing about the seeds.

That's a good idea aout the pots. Mine will probably have seeded before I plant them out and I can keep the remaining soil in the pots, label and store them 'as is' in the ground. I've done this with other species to recognize plants that sprout long after I've forgotten them.

hmm, i'm worried. i bought some rootlings at my favourite mursery a month or so ago, potted them right up and put them in the window of the garage. i haven't seen anything come up. should i take them back? are they likely dead? the original poster's came up immediately!

I planted a couple about 8 years ago, and it took them forever to get going, and there's still only the ones I planted. They are blooming for me right now (central Indiana). I sure wish they'd spread though. I found a place on my way to town that is covered with them, and they are truly lovely.

I planted two trillium g. roots in pretty deep shade and heavy clay soil between a pittosporum and an escalonia, in an area that gets daily watering by an automatic sprinkler, back in March. They weren't there when I tried to dig them up a few minutes ago. I suppose the heavy soil rotted them; I don't know the ph. Thoughts? Experiences?