Repotting Indoor Chinese Elm

Hello everyone,

I bought this small Chinese Elm at a nearby nursery today. Yes, I know it is a mallsai. Yes, I know how to pick good material. Believe it or not, this was the best looking one of them all. Had the best taper and everything. The tag on it was wrongly labeled, of course, and said it was a Zelkova Elm. Looks like a regular C.E. to me. Anyway, the tree is in full life, as according to the tag that came with the tree it came from Florida. The soil is the usual poor, peaty muck that holds too much water. I will leave this tree indoors of course, as it is still winter here. Since this tree hasn't been exposed to the seasons, would it be all right if I repotted it into something free draining? Here are some pics:

Side A:


Side B:


Soil:

I would not repot it now. Just try not to overwater it. It will not thrive indoors. For the rest of the winter, keep it as cool as possible just short of freezing. As soon as temperatures warm up, put it outdoors during the day (a Little at a time at first) and bring it in overnight until the last frost. Repot in March or April.
You will probably have to air-layer it.
Iris

I would not repot it now. Just try not to overwater it. It will not thrive indoors. For the rest of the winter, keep it as cool as possible just short of freezing. As soon as temperatures warm up, put it outdoors during the day (a Little at a time at first) and bring it in overnight until the last frost. Repot in March or April.
You will probably have to air-layer it.
Iris

bonsaisr wrote:I would not repot it now. Just try not to overwater it. It will not thrive indoors. For the rest of the winter, keep it as cool as possible just short of freezing. As soon as temperatures warm up, put it outdoors during the day (a Little at a time at first) and bring it in overnight until the last frost. Repot in March or April.
You will probably have to air-layer it.
Iris

Thank you Iris, should I let it go dormant?

If it appears to go dormant, let it. You can't force it. At least don't force it to stay awake.
Iris

Ryan,

correct me please Mrs. Cohen, there is a reference to a Zelkova schneideriana, as opposed to the Ulmus parvifolia. The zelkova one is supposed to be sub-tropical, with more of a preference to being evergreen and more tropical.

Whatever the reason, elms listed for indoors do well down here, as does the roots of a tropically grown catlin, and the seiju. I will one day obtain the hokkaido and see how that does.

I just lifted 8 or so of one mother elm's [ say zelkova s, for the discussion ] children, and replanted some 50 or so roots. If grown in very coarse soil the roots have more quality than the tops. Takes about 6 weeks for the roots and the new shoots appear becoming a new tree.
[ they were allowed to grow from around 97 or so and just chopped down once a year.]

So instead of wasting time with airlayers, you could just set up an outdoor situation or very large pot with coarse soil and use your time on the roots.

A chop before the first curve would probably yield a more workable specimen.
Best to you.
Khaimraj

* Oh, and elm roots often change into new sports. I have from another normal elm, a sport that grows only in curves, and one from an "indoor" elm that has leaves smaller than the parent, very vigorous, but larger leaves than a seiju.

Growing bonsai indoors in the North has very very little to do with how they grow in the tropics. They are on two different planets.
Ordinary Chinese elms are sometimes imported with a label Zelkova, to get around import restrictions. I doubt that there are any Zelkova mallsai.
I have grown 'Hokkaido' indoors, but as a subtropical with a fall rest. 'Catlin' is supposedly a subtropical cultivar that can be grown indoors. I have not seen any of these as really successful bonsai in this area.
I suggested an air-layer because to me, the upper part of the tree looks more promising. Try both!
Iris

Thanks Mrs. Cohen,

I do wonder if it helps to supply the air temperature of the earth and the ambient temperature of trees grown in the tropics and the same for those grown in apartments. As well as light exposure.

Has anyone on your side done any work on that ---- just curious.
Thanks again.
Khaimraj

Thank you Iris and Khaimraj!

I think I will air layer it, probably where Khaimraj suggested chopping it. The top, given time, could be used as well.

What are the dangers of it not having a rest? If it can be a semi-evergreen, why can't I let it stay awake? Just curious, thanks!

Ryan,

dormant the plant rejuvinates, trying to grow without a rest will weaken or kill it. This is why I refrigerate the Celtis / Gingko / Trident and now testing an idea of Mrs. Cohen - junipers.

Elms.
What I have been trying to determine is what really happens to this tree in the tropics from November to February. The way my house and yard are placed, the yard enters complete shadow in late October, and gets down to 19 deg.c in the air at night for hours, without sunlight this might continue for hours into the day as well.

By February the 26th [ marked it on the calendar some years ago and stuck it to my bedroon door on the inside.] the sunlight begins to return and by March the yard is back into sunlight.

Since I repot from the 2nd of January, by November, the elms will have normally root bound the pots and can be lifted out an examined.
November sees no growth on the 5, I have from China, via Holland, via UK. as their tops go.
However the roots seems to be still active and obviously the soil does dry.

I have had my Catlin and Seiju since 81' or so, and the Chinese Elms since 86' and 94' and their roots have provided all the new children.

So I wonder is it short days as light goes or cold [ 19 deg.C / 69 deg.F isn't that cold.] that makes them sleep ?

With apartments the information seen is only air temperature, but no one records the temperature of the soil. So if your comfort zone is say 70 deg.F or higher, are the trees able to rest or is it the root zone being cooler, or is it the light ?
I remember Philadelphia in winter being sunny in winter, where Florence, Italy is cloudy and dull. What is China like in winter, bright and sunny or dull and cloudy ?

If I knew exactly where these elms were coming from and their year round situation with regards to sun and temperature, I could optimize my elms performance.

All that said, my elms rest for about 4 months, no real growth, and the Catlin will form cracked leaves which yellow and fall.

In an apartment, you need to know what brings on the dormancy, cold or lack of light.
This way you could make sure they get the rest they need.
Sorry only questions.
Khaimraj

* By the way the elms via the UK, were supposed to be 16 to 35 years old, and one in particular, grows way better than the others.

Very interesting debate in regards to dormancy, temp. vs. light, you are starting Khaimraj. Thank you for taking the time to reply though!

Any clue how I could find out which works without killing my tree? There were other un-interesting trees that I could buy to experiment on. This one I liked. If at all possible, could I place it outdoors in a cold frame, let it go dormant, then once temps start heating up again, bring it back indoors to place it in a fridge for an added dormancy?

Then again, who's to say this tree hasn't already gone through dormancy? Could it be that it got cold enough in Florida to allow the tree to go dormant? Could it have been a more northern part of Florida?

Ryan,

I was either the same age as you when I started Bonsai, or 1 year older. Killed a lot of trees along the way. Elms grow easily from roots. In late spring take a few root cuttings and grow some for outdoors, grow some indoors, read, experiment, take notes. Be kind to yourself, these things take years and you have youth on your side.
[ just grow for trunks, no training.]

Jack Wickle at Jerry Meislik's site has a good article for growing under lights, see what he did.

I am presently using a plastic aquarium to see if I get a 1 and 1/4 inch cutting to grow roots, how does that grab you for an experiment. Thanks Ryan.
Be prepared to experiment, with sense.
Khaimraj

Khaimraj Seepersad wrote:Ryan,

I was either the same age as you when I started Bonsai, or 1 year older. Killed a lot of trees along the way. Elms grow easily from roots. In late spring take a few root cuttings and grow some for outdoors, grow some indoors, read, experiment, take notes. Be kind to yourself, these things take years and you have youth on your side.
[ just grow for trunks, no training.]

Jack Wickle at Jerry Meislik's site has a good article for growing under lights, see what he did.

I am presently using a plastic aquarium to see if I get a 1 and 1/4 inch cutting to grow roots, how does that grab you for an experiment. Thanks Ryan.
Be prepared to experiment, with sense.
Khaimraj

Thanks again!

I've got 2 seperate aquariums already up and running with lights and humidifiers for my tropical trees. I could easily place my elm in with them, but that is if I do not want the tree to go dormant. I read online somewhere that these trees can go up to 2 years without needing dormancy, but they will then drop leaves no matter the season in order to rest. Is this true?

Don't believe everything you read online. Yes, you might be able to force an elm to stay awake for two years, but why would you? I don't know how to make it clearer, that an elm is not an indoor or tropical tree and it needs to go dormant in the winter. If it doesn't get its winter rest, it will eventually become weak & it may die.

<<If at all possible, could I place it outdoors in a cold frame, let it go dormant, then once temps start heating up again, bring it back indoors to place it in a fridge for an added dormancy?
Then again, who's to say this tree hasn't already gone through dormancy? Could it be that it got cold enough in Florida to allow the tree to go dormant? Could it have been a more northern part of Florida?>>
Try to get this tree into a normal cycle. Since it has been indoors this long, I would not put it in a cold-frame where it will freeze. You can't put it in a fridge, because it is accustomed to light right now. Put it in an unheated window for the rest of the winter, where it will be cold but above freezing. As soon as it goes above freezing outdoors, put it outside gradually.
I assure you the tree has not had any dormancy in Florida. It was probably in a greenhouse.

<<So I wonder is it short days as light goes or cold [ 19 deg.C / 69 deg.F isn't that cold.] that makes them sleep ?

With apartments the information seen is only air temperature, but no one records the temperature of the soil. So if your comfort zone is say 70 deg.F or higher, are the trees able to rest or is it the root zone being cooler, or is it the light ?
I remember Philadelphia in winter being sunny in winter, where Florence, Italy is cloudy and dull. What is China like in winter, bright and sunny or dull and cloudy ?

If I knew exactly where these elms were coming from and their year round situation with regards to sun and temperature, I could optimize my elms performance.

All that said, my elms rest for about 4 months, no real growth, and the Catlin will form cracked leaves which yellow and fall.

In an apartment, you need to know what brings on the dormancy, cold or lack of light.
This way you could make sure they get the rest they need.>>

The question is actually rather complicated. If you Google on Dormancy in Temperate Trees, you will get a lot of details, including applications to bonsai.
The main trigger for dormancy in most temperate trees is daylength. As the days get shorter & photosynthesis decreases, the tree is prompted to shed its leaves (if deciduous) and prepare for winter. In the spring, after a suitable cold season, increasing daylength causes the sap to rise & buds to open.
Outdoors in the North, the roots continue to grow for quite a while before the ground freezes. In an apartment, the temperature difference between the top & the roots is insignificant. If the days shorten but the air remains warm, like on a windowsill, a temperate tree may try to go dormant & shed its leaves, but the warmth will cause the tree to continue to expend energy. This may be fatal.
Iris

Mrs. Cohen,

thanks again for taking the time to respond. It looks as though I will have to find a specialist on elms to refine some of this information.

Ryan, it is best that for now you follow Mrs. Cohen's advice, we can trade notes in late spring, when you get outdoors.
I will see what I can find out with regards to why they grow and thrive in the tropics.
Stay well.
Khaimraj

I have been watching the debate about chinese elms not having a proper dormant period for a while. The majority says keep them outside all year even in zones 6- to keep up vigor. I just got back from a local nursery run by a Korean family, into bonsai generationally for many years, who has many very healthy chinese elms and even junipers that are 40yrs plus in age and in very active growth during a harsh zone 5a Canadian winter. Really made me think that forcing my ten year old chinese elm into a zone 5 dormancy was the wrong thing to do because it's been treated as an indoor for ten years. With enough care and diligence, any requirments for a tree can be met indoors. Its up to the grower. Every plant has a required dormancy period, even tropics. doesnt mean they have to drop leaves and lose vigor.

Khaimraj Seepersad wrote: .... .... So I wonder is it short days as light goes or cold [ 19 deg.C / 69 deg.F isn't that cold.] that makes them sleep ?... ....

bonsaisr wrote: .... ....The main trigger for dormancy in most temperate trees is daylength. As the days get shorter & photosynthesis decreases, the tree is prompted to shed its leaves (if deciduous) and prepare for winter. In the spring, after a suitable cold season, increasing daylength causes the sap to rise & buds to open.
... ...

Having no specialized knowledge, I would dare say that it could be a combination of the two... Since shorter days start and last during fall -> winter -> cold and longer days start and last during spring -> summer -> hot
Comment, Mrs. Iris?

sorry to highjack the thread briefly, but I've got an elm I want to cut in half to improve the taper and because the top's rotten. It also needs to be repotted. I would do the latter in march, but not sure when to cut it and wonder if doing both at once would be stress it too much?

my nellie wrote:
Having no specialized knowledge, I would dare say that it could be a combination of the two... Since shorter days start and last during fall -> winter -> cold and longer days start and last during spring -> summer -> hot
Comment, Mrs. Iris?

As I said, the main trigger for seasonal change in plants is daylength, since this is consistent and predictable. The ensuing temperature changes are extremely variable. If it is too warm in the fall, or there is a sudden early cold snap, the trees may be damaged, but it usually won't kill them.
If you notice the migration patterns of birds, some of them in the North start to migrate in August or September, when food is still plentiful, so they will reach their southern destination in time. This is also triggered by changes in daylength.
One reason our dogs shed so much is that going outdoors and then in, they are exposed to constant changes in both temperature and daylength, hopelessly confusing that little center in the brain that controls hair loss & growth.
Iris

Thank you very much, Mrs. Iris!

Thank you all!

I've been told not to repot this tree now by others, and that if I wanted to air layer I would have to do that next year, then do a repot the following year. Is this true? Or can I just air layer, then slip pot into something free draining (once the layer is done) in one year?

The original query was about repotting this poor victim. Since it is unsuitably potted, that is probably your first step. I trust by now you have gotten it into a suitable location. Since you are in northern Virginia, probably Zone 7, it won't be long before repotting time anyway.
Check with your local bonsai club or the National Arboretum for optimum potting time for elm, which I guess will be some time in March. Pot in moderately coarse soil, in a pot one size larger than you would think. I wouldn't do any root pruning. It will soon be time to put it outdoors (little by little), but keep it out of the sun & wind until you see signs of new growth. Once you see it is growing well, you can probably air layer it this year, in May or June.
Iris

I suspect I know where this Chinese Elm came from in South Florida. In that climate it may never go dormant, but the new leaves will push off the old leaves. I have one of these, probably from the same source, but I have had to for a few years, it still has last year’s leaves on it, I am about 150 miles north of the Chinese importer.

To chop or not? I chopped the one I have, but I haven't repotted it. At this point I am considering putting all my elms in the trash as they all seem to have a disease known as "phloem narcosis" (Iris or Jim can correct this term) and there is no cure.

I don't know where the disease came from; this Chinese import is not responsible because some of my Elms had the disease before I got this tree.

Elm Phloem Necrosis

http://extension.missouri.edu/publications/DisplayPub.aspx?P=G7254

Billy M. Rhodes wrote:I suspect I know where this Chinese Elm came from in South Florida. In that climate it may never go dormant, but the new leaves will push off the old leaves. I have one of these, probably from the same source, but I have had to for a few years, it still has last year’s leaves on it, I am about 150 miles north of the Chinese importer.

To chop or not? I chopped the one I have, but I haven't repotted it. At this point I am considering putting all my elms in the trash as they all seem to have a disease known as "phloem narcosis" (Iris or Jim can correct this term) and there is no cure.

I don't know where the disease came from; this Chinese import is not responsible because some of my Elms had the disease before I got this tree.

Are you sure you have the same disease Billy? The information says it only infects American and Winged Elm.