Chinese Elm, southern strain

I posted a question about this tree once before, but I couldn't find it in Search. I got it last year in a raffle and I thought it might be a named cultivar. These are shohin trees imported from China and I gather there are a lot of them in UK. I discovered they are only half-hardy and the one I had was damaged by the cold in my winter porch and went dormant until July. Meanwhile I bought another one recently. It is coming along, but it is potted in nursery semi-bonsai soil (in a bonsai pot). It will rot in my fall conditions. Can I safely repot it in early September?
Iris

Hi BonsaiR,

This is what Graham potter say about them:

Chinese Elm Tree
Ulmus parvifolia. Chinese elm are probably the best and most robust species used for Bonsai. The small oval serrated edge leaves are perfectly in proportion and the tree makes wonderful tight and fine twigging within just a few growing seasons. Very vigorous and hardy outdoors in most areas. We recommend keeping Chinese Elm Bonsai outside where temperatures do not drop lower than -6 Celsius. If kept outside the tree will lose most of it's leaves in winter thus displaying it's lovely fine ramification. Trees kept outside also develop incredible flaking bark after a few years. Prefer to be cool over the winter if kept indoors.

Keep in full sun to partial shade all year round. Water and feed very well. Re-pot every year if you want to maintain vigorous growth. Once fully mature re-pot every second year.

Myself, ive re potted them or slip potted them whenever ive felt like, with minimal fuss from the tree..

And from the Tropics zone 13
Ms. Iris,


repotting is done after 2nd January, when temperatures are in the high 80's by day, around 70 to 68 deg.f from dusk til late dawn, the occasional 66 thrown in.
Best of growing.
Later.
Khaimraj

If I could find them around here,I would certainly grow them.Looks like my winter temps are similar to your West Indies ones.Maybe I will get lucky.

These replies are not much help in USDA Zone 5. However, since it is a tough species, I can probably repot in September. Standard practice in this area is that most trees in the ground can be planted after Labor Day (first week in September). Where do you live, Geo? It should be on your profile. Chinese elm is sold for bonsai all over much of the world.

It is in my profile and listed next to my post .Baja California,Sur. And ,believe me ,in a small town and one badly run Mexican nursery,it ain't easy!

I forgot, if I'm not officially logged in, that information doesn't show. Can you import plants at all?
Iris

Chinese elm are chinese elm. They can take temps of below 20 degrees F. They can also live in sub tropic places where they will stay evergreen. All they need is acclimation.
I ordered 2 from South Carolina where the winters are mild. I kept them outside all year the first year,the second I gave them some winter protection. Last year it didn't matter.Temps of 35 below and more did all of my zone 5 trees in.

Sorry Mr. Frary, I beg to differ. This strain is from southern China and is not hardy. A Seiju that spent the winter next to my southern elm was not damaged from the cold, nor were any previous Chinese elms. Bill Valavanis' advice is to treat it as a subtropical, give it a cool rest in the fall, then put it under the lights as I do with subtropicals like pomegranate.
Here are my two specimens. The first one is the original tree from last year. The second is the newer one that I have to repot in September. Both in 6 inch 15 cm pots. Trouble is, I don't know which one to keep, so for now I have two. Any suggestions?
Iris

Oops, forgot the pictures.





Iris

The Seiju will be a little hardier because of the rougher/thicker bark. the normal (Chinese elm the smoothbarked one) isnt as hardy as the rough barked one, but thats not to say it isnt a tough little tree, its a tree after all and wants to be outside, it just needs to adapt. even more so if it was being previously kept in doors. its semi evergreen and needs a period over winter without feeding. if not fed too heavily they will actually drop some leaves over winter. if you want to keep a smooth barked chinese elm outdoors for the winter, it will have had to be outside from march/apr.....in time they will start to develop craggy bark, when kept outside.