Chinese elm

Does anyone know much about giving chinese elms a dormancy and growing them indoors? Ive heard people grow them indoors, and also that some people give them a 42 to 45 day dormancy peroid and then take it inside to bud back out and grow until spring and then put it back outside? Insight? Thanks Jake

Most varieties of Chinese elm, & the normal type, are hardy deciduous trees. They belong outdoors all year round. They will winter in southern ohio with a little protection. Bringing them indoors is foolhardy.
There are two exceptions. The cultivar 'Hokkaido,' the one with very tiny leaves, is not hardy. in the North, it is left outdoors until frost, and then wintered indoors in greenhouse conditions. I don't know if it will survive on a windowsill.
The other exception is the cultivar 'Catlin,' which reportedly originated at the southern end of this species' range. It is said to be amenable to being grown indoors. I would treat it like 'Hokkaido,' except it might grow on a windowsill. Like all "indoor bonsai," they should all go outside for the summer.
Iris

I allow my Chi-elm a full winters dormancy under my house at a constant 30F and I am rewarded with such vigorous growth in spring and all summer I can barely keep up, give them a good long rest and they'll love ya for it.

Great! Thank you both very much. I never really use window sills alone though. I use terrariums with lights and humidity and i put them in front of the windows just to make sure the plants get enough light. they seem to love it. My tropicals grow better in those conditions than they do outside in the summer. I have 4 chinese elm cuttings in one tank and there growing like there on steroids so thats why i was asking. Thanks again, Very helpfull. I always want whats best for my trees. Jake

Every time sunlight passes through a transparent medium such as glass a phenomena known as the red shift occurs, the spectrum of the light shifts more towards red, and thus produces heat. This is how greenhouses work and why putting your hand in front of a sunny window feels warmer than if you placed it out in direct sunshine on the same day. With your terrarium in front of your window the sunlight passes through 2 pieces of glass, and though losing intensity, the shift to infra red allows heat transference Your tropicals are probably thriving due to the heat that is allowing them to grow faster.

or at least thats the nearest to how I understand the principle.
-Jay

I travel quite a bit and so have to entrust care of my trees to my "apprentice"-- my thirteen year old grandson. On a recent long trip, he let one of my elms dry out. It lost its leaves, but put out a new flush of growth, and will be just fine as long as it doesn't happen again. The new growth has not yet hardened off, and we are expecting a frost in a couple of days. So. . . I am going to be bringing the tree inside until the foliage hardens off. But, as soon as it does, I will be putting it back outside.

Tim Ahlen
Dallas, TX
Zone 8

In your case, I would not put the tree outdoors this winter. Keep it in as cool a location as possible, but just above freezing. After the current flush of leaves hardens off, put a baggie around it & put it in the refrigerator, or put it on a windowsill in an unheated room.
Iris