Hello guys,

Im unsure if I have actually killed my two acer bonsai - a deshojo and a tridant maple

I repotted them as they were heavily rootbounded in marts as weather was getting warmer, though there was no signs of budswelling at that time.

Suddently the weather turned in april, and some evenings we had even minus 3oC. Over the last week weather has become slightly warmer, but my 2 acers shows no sign on budswelling at all, while my other larger japanese maples in my garden is already in full leaf.

Now Im unsure if the rootwork back in marts has actually killed my trees. Do you guys have any experience with repotting/rootworking too early?

I frequently repot in January. Also maples. Trees do not die of the repotting done early, if you provide good aftercare. A singe night with low temperatures will not be thecause of a dead tree. My maples got up to -4 I think, after leafing out. I expect them to reflush.

More likely, you cut too muf off of the roots

Hello leatherback,

Yeah, my second thought was also, that i have cut too much off the roots - that can potentially kill the tree right? Since we are in may now and temperature is 10+ degrees every day, and the trees has no signs of bud swelling

-3 or -30 celsius? The latter could be a problem. If it havent started to bud at all it could be because of too cold during winter.

minus 3 degrees:)

This winter has not been that cold, so I dun think that it is the problem. beside that all the other larger Acers in my garden are in full leaf now.

My understanding is that the repot in marts was okay, but the heavy rootwork when no sign of budswelling might have drained the tree of too much energy, that might potentially have caused its demise:(

You guys know that temperature is not the biggest factor for deciduous trees to come back from dormancy right? It is actually the sun that gives the signal. Sure warm weather might speed up things a little sometimes, but trees know it is time to start pushing growth by knowing how long the sun has been out there for a day. Where I live, I have found the best time to re-pot is around April 5th, march might work but it is early. Where I live, buds start coming out around April 5-15,and right now trees are starting to push new growth (May 2). So it depends on where you live. Just look for when buds come out, and do it then. A little early shouldn't kill the tree, and even a lot early for deciduous trees should be fine. But optimal time is when buds just come out. Forsythia are also a great indicator, the flower very early because they put out the buds on the fall. So when you start seeing the first Forsythia flowers, it is time to repot.

eangola wrote: You guys know that temperature is not the biggest factor for deciduous trees to come back from dormancy right?

Not true. It can depend on light levels, temperature, amount of water, or a combination, depending on the species.

eangola wrote: It is actually the sun that gives the signal

Actually, it is the length of the night that is critical.

Auk wrote:

eangola wrote: You guys know that temperature is not the biggest factor for deciduous trees to come back from dormancy right?

Not true. It can depend on light levels, temperature, amount of water, or a combination, depending on the species.

Let me correct myself there, after re-reading an article I had in my bookmarks:
"It is believed by some researchers that cool temperatures are needed for the plant to enter true-dormancy."

Only some... so saying that what you said is not true, is not necessarily correct

However:
"Temperate woody plants once in true-dormancy require chilling to enter post-dormancy."

It is complicated. Hereś the link:
dendro.cnre.vt.edu/forestbiology/htmltext/chapter6.htm

It is a combination of things. Night length and dropping temperature signal the tree to start autumn routines. Once started, this can for temperate species not really be halted, only slowed, by warmer temperatures.
Once dormant it is the combo of time since going dormant (which stops mid winter growth during a warm.spell) and spring indicators such as temperature that trigger it. It certainly is not purely light druven. Else spring could never be early or late..