Ulmus Parvifolia woes!

RJMacReady

Hey there BonsaiTALK, new member here. Even though I've been with, read about and loved Bonsai Trees for about 11 years, I still don't really know how to care for them properly. I bought an Ulmus Parvifolia from the garden centre where I work and have had it outside ever since. It looked dowdy and a little sad, but it now looks great! I have a very large number of Bonsai books that contradict themselves. One book says its best for Ulmus Parv. to be outdoors, another says they can be perfectly happy indoors. And to top it off, a website told of great woes concerning it losing its primary buds if it doesn't have a period of dormancy? What is a man to do!?

Any advice greatly appreciated.

PS. It's sitting on my windowsill right now, since I'm undecided as to what information I should follow.

Advertisement

rockm

ALL trees are happier outside, period. Trees were not meant to be grown indoors. This is true even of tropical species that do better with "vacations" outside in the summer.

Chinese elms are sold as "indoor" trees because they are among the species that can tolerate indoor conditions, not because they're "happy
with the treatment. Far from it. They endure such treatment. Chinese elms are deciduous temperate zone plants. They require a period of cold dormancy. Inside they linger and die.

Get the tree outside ASAP, if you want it to be healthy through the winter and next spring. Trees outdoors are in the mid-stages of preparing themselves for winter dormancy. This preparation is started by shortening day lengths as we slide towards autumn. The process started back in June. If you keep your tree inside now, you will have to overwinter it indoors--which is generally exteremly tough on the plant.

RJMacReady

Ok doc, sounds good to me! Funny thing is, I can actually see how the plant is happier outside. The tree is comfortable in the light rain and gentle breezes.

On that topic, when the winter months do eventually begin rolling in, whats the best method of keeping the Bonsai? Should I build a cold frame/cover the tree with fleece or somehow protect it? My Ulmus is the variety with smooth bark (Which I might add a book told me to keep indoors, because it's less hardy than the corky-bark type).

What do I do?

rockm

Let the tree get hit by a few frosts and even freezes in autumn. This helps the tree "harden" itself for the coming winter.

Find a sheltered spot in the garden out of the wind, on the ground. Place a few bricks on the ground in the spot, put the bonsai on top of them--making sure the drainage holes aren't blocked, water it well. mulch with shredded pine bark halfway up the trunk all the way around, making sure the mulch pile gently slopes to the ground. Water the mulch all the way through. Let the plant alone for the winter, checking every week or so, to make sure the soil stays moist. You don't want soggy, you want moist.

Don't worry too much about frosts and freezes. They aren't going to affect the tree much if the temp doesn't drop much below 20 F for long. You're not trying to keep the plant "warm"--which is a bad thing for overwinter. You're trying to keep the plant's roots at a constant lower temperature. That temperature can even be below freezing--provided it's not much below 20 F for long. You don't want constant freeze/thaw cycles. Make sure the plant doesn't get direct sun, or you wil have problems with winter kill on the top portion.

Books can be wrong or inaccurate...

RJMacReady

Thanks for all your advice. Since I live in England, the temperatures are slightly different. 20 Fahrenheit is about -6 Degrees Celsius. December is generally just wet, windy and cold, so the only time we get snow or freezing that bad is in January.

As far as mulching goes, cover it completely to half way up the trunk: Is that covering the pot too, and the bricks? Or keep it contained within the pot? And what month am I best to be carrying this out? Nov/Dec?

Alasdair

You'll probably find late february, march and early april the most dificult for your tree. It starts to get warmer and your tree will start to leaf out and do its spring thing, but a late frost will damage all the new growth and buds. At that time of year keep an eye on the weather forecasts and shelter your elm if it we have a late frost. I bring mine just inside my back door where it stays realativly nippy, but doesn't freeze. Then i put it back out in the sun through the day and it seems to do just fine.

Al

__________________
I can feel another "I wish that was my tree" moment coming on...
Currently studying BSc Plant Biology at the Universty of Wales, Aberystwyth

rockm

Keep it in the pot--or not. I leave my trees in the pots over the winter. Some remove them. I leave mine in because root start growing before you unover the trees for the spring. This can cause some problems if the roots grow too big to get back into the pot--although if the tree is due for a spring repotting anway, this doesn't make that much difference, as you will be root pruning the plant.

Anyway, Mulch over the pot and the bricks (which are there to provide a drainage field underneath the pot. If you put the pot on top of mulch or the soil, it's likely to become clogged and water will pool at the root zone. That's VERY bad.

You're after a big mass of mulch over the tree's roots. This mass won't really keep the tree "warm" --although it wil probably keep it warmer in the colder months for the most part--it will "lag" temperatures, though. That is, keep temps from swinging too quickly, or reaching extremes. The mass will also keep the roots cooler in the spring, an important thing to prevent premature growth during warm snaps before actual spring arrives.

RJMacReady

Well I work in a Garden Centre, and we usually cover the plants (From December to about February) in the evening before leaving, then uncover them at about 9am. Would fleece/netting be sufficient to keep the frosts off until they wane and disappear?

EDIT: Thanks for your info too, rockm.

Alasdair

A good layer of fibre fleece should do the trick. I don't know this from experience so don't hold my word, i'd wait and see what someone else says, just incase.

Al

__________________
I can feel another "I wish that was my tree" moment coming on...
Currently studying BSc Plant Biology at the Universty of Wales, Aberystwyth