It is a real tree, but no tree hibernates, they just go dormant, and it may be what yours is trying to do. However, bringing it indoors is not the way to let it happen. Where do you live - it matters very much to whether the tree should and can be outdoors or not. You also need to say how often you water and how you do it, and how fast the water runs through the soil, as well as the type of location it's in (both in and out) to be able to diagnose things better.

I live in the UK. (it is 0 degrees and snowing at present to give you an idea of the weather here right now!)

I water whenever it is dry and do it by submerging it in a tray of water left standing. I also mist it whenever it has been in for more than a few hours.

When it is less cold, it is left outside on a south facing patio in the sun all day. When I being it in (due to frost etc), it is in a south facing room (about 10-15 degrees) in front of a French window.

The water drains through the soil at a medium-ish speed (the soil being quite rich and dark in composition).

Thanks for the help so far :)

Chines Elm need to go dormant for the winter to stay strong. They can survive a year or two without dormancy, but it weakens them quite a bit.

By bringing it in when it gets cold, you are probably breaking its dormancy and then placing it back in the cold is slowly killing it.

chinese Elm can survive pretty cold temps, including temps below freezing for short periods of time (say, overnight or for a day or so). Living in the U.S. i am used to dealing in F, not C so will have to give you temos in that.

To go stay dormant, they need temps that stay pretty consistantly below 40* F. Like, I said, not sure the exact conversion, but would guess htat is below 10*C.

The best way to witer them is either in an unheated garage (so its cold, but not below freezing for extended periods and protected from frosts) or to leave it outside and cover the entire pot in mulch to prevent complete root freezing (freezing of the roots is the real danger of cold temps).

If you are scraping the bark and the result is brown, it sounds like htat part of hte tree may already be dead, if it still green lower down though, the roots and trunk are still alive.

At this point, your best bet is to bring it indoors and place it i a sunny window at room tempurature. The tree is most likely no longer dormant and as it takes weeks to fully go dormant, it will jus tdie if you leave it outside. Bringing it in even after a short dormancy is best now, and will give it the best chance of survival.

Good Luck!!

Your tree, likely potted in bad 'potting soil' originally, is probably holding a fair amount of water between times, and it should be repotted with half the mix changed to grit (the small size glassy looking gravel sold for aquariums is good, along with some perlite) and all mixed together, with no shards or pebbles on the bottom or anywhere else, and the water should drain out faster. Never let it sit in drain water (it'll rot roots). Water only when the top 1/2" of the mix is dry, and never, ever water by submersion! It doesn't allow 02 into the soil, or 'old' salts and chemicals to wash away. Also, do not mist your tree... it's a waste of water, and can promote mold, etc. If you're concerned about humidity, keep a wide tray of pebbles and water under the pot, but never allow the water to reach the pot. Don't keep bringing your tree in and out. It may well be too late to acclimate your tree to being out this year, and C. elms can survive one season indoors if not left in a too-warm/dry place - just be sure it's getting lots of sun.

Thanks..

The thing is there is SO much conflicting information!

I read submersion was the best way to water it and that misting it when indoors was good for it.

The tree was repotted by a bonsai specialist about 18 months - 2 years ago now, so I am pretty sure the soil compo is correct for the tree. Should I still change it?

I've put the pebbles and water under the tree already and it's being kept at a constant 15degrees C or so (Just below room temperature) in front of a large south- facing window.

I'll see how it gets on

Thanks

Lucy is right, submersion is not a good way of watering. It works for certain applications - like after trimming the roots and providing a root stimulator and can be used for feeding occasionally, but the roots need oxygen and the water running through the pot pulls air into the soil. Also, unless you are using rainwater, the water will contain calcium and other minerals which you will see start to stain the soil white. Pouring water helps to flush these out (yes, I know repeating what Lucy said).

Misting the leaves is "supposed" to help keep the tree moist - instead of humid and it just doesntwork. Yees, the trees can absorb some water through theoir leaves, but not enough to make a difference.

As for the humidity tray. honestly, it doesnt hurt to have it, but it doesnt work - the theory is that directly above the tray will be more humid, however - nature doesnt work this way. evaporation is not sufficient to raise the humidity unless the room is sealed and any slight increase will mix with the air to even itself out resulting in no practical increase.

Like I said, it doesnt hurt, but its no replacement for a humidifier.

I'd keep it in the south facing window the rest of the winter - it should be fine (so long as it is still alive now).Then come late spring, put it back outside - do not put it out in early spring, or the cooler htan house temps will cause it to try and go dormant again. Then, next winter, just put mulch around thepot and leave it outside out of the wind.

good Luck!!!

Thanks again everyone...

We have a greenhouse that is in a shady-ish part of the garden.. I am wondering if this is a good place for it next winter? as it gets pretty cold in there (but it will keep the frost and the wind away) and with the door and the roof panels open I would imagine it would be a good spot for it for next winter?