Lilium kesselringianum?

[gote]

I wish I knew.
Sensitive plants should be moved just before new roots develop but I have not enough experience from the caucasican lilies.
I would separate them after one year simply because small plants transplant better.
Göte

[Leena]

I would separate them after one year simply because small plants transplant better.

Thanks, I will do that next summer.  Martagon lilies transplant best in a short time just after flowering, perhaps the best time for these also would be in late July or early August?

[Gene Mirro]

My experience with all the lily species I have grown is that the best time to transplant is in the Spring, just as the new shoots emerge from the soil.  The bulbs have very few roots then, and the plants do not show any signs of stress.  I know that a lot of people say you should transplant in the Fall, but the bulbs are full of roots then.  The commercial growers dig in the Fall because that is the only good time.  In Spring, the fields are too muddy.

[gote]

Gene
Have you tried to transplant martagons in other times than the spring?
We have a lawn that cntains a lot of Eranthis, Scilla, Chionodoxa and Crocus. In order to allow them a reasonable life span we start cutting the lawn latish.
Lilium. martagon seeds into the lawn and grows to flowering size in spite of being cut down in early summer. Thus I am not worried about moving them in the summer and removing the stalk. I have the impression that the new roots that emerge in the summer remain over the winter and are needed in the spring. I thus try to move them before the new roots emerge. (Of course I avoid moving in the fall)
Woodlanders like martgons and Trilliums seem to be adapted to do the most of a very short window in time that starts with frost disappearing from the soil and ends when the trees have fully developed folage. They do this by ensuring that the root system is fully developed at the time when spring sets in. Thus they resent autumn/winter/very early spring disturbance.
I would really appreciate your comments
Cheers
Göte
 

[Gene Mirro]

I have moved martagon album in the Spring.  I don't remember if I have ever moved them any other time.  There may be other good times to move them also.  But I don't like the idea of moving any plant in midsummmer while they are in full growth.  It sounds risky.  But if it works, that's all that matters.

[Leena]

I have moved L.martagon several times in spring and more in summer and once in the autumn, and in my climate they transplant better in summer, just after flowering before they start to grow new roots. If transplanted in the spring they usually grow poorly and  abort the flower buds the first year but survive and do better the next year. If moved right after flowering they flower the next year well (but of course I cut the stems from the half way and lose the seeds that year). When I had moved them in the autumn, they reacted like when I moved them in the spring, but once I had potted martagon bulbs in the autumn and kept over winter in cool cellar and they rooted fine during the winter and flowered next year. I think when I moved them in the autumn they didn't have time to root properly before the winter came, so this might be also a matter of climate.
I agree with Gote that they have most roots already ready in the spring and that is why I here they have suffered from the transplant in the spring.
However other kinds of lilies I have transplanted (Lilium bulbiferum and its hybrids), transplant fine in the spring, to me it seems martagons are more difficult.

[gote]

Many woodlanders are adopted to a growing season that starts very early and also ends very early. In order to get a speedy start they do not have the time to start growing roots in the spring. Thus they must have the roots developed before frost stops all action. Some of them like Trillium and Lilium martagon start growing next year's new roots already at the time the flowers begin to fade. Others like woodland Corydalis and Leucojum vernum start later but well before Autumn sets in.

Seeds seem to follow the same procedure. A  species that has mature seed in the summer will develop roots (and sometimes a microbulb) in that summer and sprout above ground in the following spring. (Like Leucojum vernum). Since the seed is designed to germinate under ground fairly soon it has a low shelf life and may be dead when sent out in a seed exchange.

Species that develop the seeds later (Like L. martagon and Trilliums) lie dormant until the next summer when they have time to develop the roots and then sprout in the second spring. They might have a better shelf life - L. martagon has.

Deno showed very convincingly that temperatures are important in triggering root development. Leena and I have similar climate. Gene's may be different. Thus our experience might be different.
 
The best  time to transplant any plant is probably just before new roots develop. The problem is to know when this is. Many plants will develop new roots any time of the year. However, the mechanisms that prompt some woodlanders to develop roots in time for the spring also seems to prevent them from forming roots at other times. 

I think observations about the time for root development would be very valuable for all of us. Perhaps such information should be collected in a sticky thread.
I am only 100% certain about Trillium grandiflorum which I have moved in various seasons. I am 90% sure about Lilium martagon both start root formation when the first flowers start to fade.

Cheers
Göte

   

[Leena]

The best  time to transplant any plant is probably just before new roots develop. The problem is to know when this is. Many plants will develop new roots any time of the year. However, the mechanisms that prompt some woodlanders to develop roots in time for the spring also seems to prevent them from forming roots at other times. 

I think observations about the time for root development would be very valuable for all of us. Perhaps such information should be collected in a sticky thread.
I am only 100% certain about Trillium grandiflorum which I have moved in various seasons. I am 90% sure about Lilium martagon both start root formation when the first flowers start to fade.

Thank you Gote for the explanation about root forming.
I will have to pay more attention to it in different plants when I move them. I don't have other mature woodland lilies than L.martagon, and also my Trilliums are quite young. I have seedlings and couple of bigger plants planted in the last couple of years. I have Trillium chloropetalum (var giganteum) planted in autumn 2012, it came up and flowered in spring 2013 but wilted in June quite soon after flowering in May. I thought that perhaps it hadn't had time to root properly because it had been planted in October and the winter came soon after. In spring 2014 it flowered well and kept it's leaves a lot later in the summer, and in autumn I was surprised to see it was already peeping from the ground in late October. I covered it with mulch and hope it will wait patiently until the proper spring. So it must have grown new roots early when it was trying to come up already in late autumn.