Chinese elm went dormant indoors?

[Yoshi]

Hello Helpful Gardeners

I currently have two outdoor bonsai and two indoor bonsai. Last year, mid august (just before autumn), I also started some sprouts from different species meant to be kept indoors. Three of the sprouts where Chinese elm's. I keep them in my bedroom where the temperature is always at a minimum of 15c (59f).

The sprouts started out nicely and quickly had two/three sets of true leaves. Then when it got a bit colder and the daylight got scarce the color started changing from green to pinkish purple. It actually looked really nice . Two sprouts then dropped all of their leaves and are now just tiny little twigs. The other sprout only got purple at the leaf tips and is still holding on. It however has not grown for over six months. It is almost as if it is hibernating with it's leaves on. After a month of growing light treatment (the bulb that my serissa loves ) it still has not budged!

Today I did a mini scratch test on all three the sprouts, they all have a healthy green color underneath and are definitely not dead.

So my questions are:
1. Is it normal that inside elm's go into dormancy?? (never heard of it)
2. For the leafless sprouts: now that the weather is getting warmer and there is plenty of light, will they come out of dormancy naturally, or will I have to do something to activate them?
3. For the sprout with the purple leaf tips: how do I get it to ever grow it again, am I stuck with a nanosai sprout here?

Thanks for reading!

Greetings,
Yoshi

[tomc]

That purple leaf tip, or under-leaf is cold related inhibition to potasium uptake. It should pass as light and heat levels increase.

Again if you really want local to you advice about care for a tree, ya'all have to amend your profile or signature block with enough geographical identifiers to make it possible to advise.

Your elms are going out of doors as spring rolls around, no matter what. when ever that is seasonally true for you.

[Yoshi]

Hello Tomc, thank you for your reply .

I added my location: the Netherlands. We have freezing dark winters and hot sunny summers.
Although the heat in my room is regulated, I am afraid I kept them too close to the cold window. That and the little daylight probably triggered it's dormancy. I guess when I removed the sprouts from the window and gave them a bit of extra lighting I tricked one out of going into dormancy fully. The one with the purple tips that is.

I know when a Chinese Elm goes into dormancy once, it must go into dormancy every year. So instead of keeping them inside, they will be outdoors trees now. I will try to keep the not fully dormant Elm indoors trough fall and winter though.

I guess I got a little confused because I have a friend who has a fully grown Elm indoors. No special treatment, it just sits by a large window year around. He has had it for about 5+ years now. No growing lights or nothing. Maybe sprouts are a bit more sensitive eh .

Thanks again

[Yoshi]

Yes, they made new leafs and came back as u predicted