Author Topic: Japanese Maple buds moving  (Read 3491 times)

bwaynef

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Japanese Maple buds moving
« on: January 02, 2011, 07:50 PM »
I have a handful of j.maples in similar (grow) pots.  Some were repotted this spring and some were dug from a grow-bed in preparation for my recent move.  Since we were having (TONS of) work done on the house before we moved in, we lived a few (LONG) weeks with my inlaws and had all of our stuff at their place.  The trees were placed against the back of the house in a fairly exposed location.

All was well until it was forecast to get down to 16ºF and I thought it best to move some of my more tender plants to my greenhouse (that I hastily resurrected).  I got the my satsuki (and several flats of cuttings), shimpaku cuttings (that I'd started in about October or November), Tridents and Japanese Maples, and tucked them inside with a small heater.  I ordinarily would've left the japanese maples out, but didn't want to risk it with the recently collected trees, and didn't have time to distinguish which trees were recently collected and which ones weren't.  After threat of dangerously low temps passed a week or so later, I turned the heater off and left the greenhouse to its own devices, which can easily get 60º+ even when daytime temps are freezing.

I was out there the middle part of this week and thought I noticed swollen buds along the trunk of one of those japanese maples.  I immediately sat it outside the greenhouse to prevent the warmer temperatures from stirring those buds any quicker.

My question:  should I leave it alone and let the rest of winter take its toll on the tender new growth?  Should I rub the buds (and any growth) off now and hope it resumes dormancy? 
 

donmaple

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Re: Japanese Maple buds moving
« Reply #1 on: January 03, 2011, 08:44 AM »
bwaynef, be careful putting those maples back out in the freezer. The buds will be the least of your concerns. If the sap is starting to flow a severe freeze will freeze the cambium and split the bark along the trunk. I lost at least two Japanese Maples in Birmingham, Al when we had a LATE hard freeze. Keep them as cold as possible but try to avoid drastic changes in temperature. Nature usually cools them down slow and warms them up slow, but she can also be fickle. Hope this helps you some and good luck! Don.
 

rockm

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Re: Japanese Maple buds moving
« Reply #2 on: January 03, 2011, 09:29 AM »
If the buds remain unopened, the tree still retains its winter hardness and it will be fine outside with no assistance.Once leaves break from teh buds (even if you can juuust make out the edges of a leaf pulling away from the bud, the tree has mostly likely lost its winter hardness and ability to cope with colder temps.

For what it's worth My JMs here in N.Va. get only a wind break and mulch in the winter--and have experienced single digits sometimes for days in late winter. I've found that heaters are a bad idea for overwintering temperate zone trees for the reasons you're experiencing.

 

bwaynef

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Re: Japanese Maple buds moving
« Reply #3 on: January 03, 2011, 10:01 AM »
Rockm, I was more concerned with the just-collected roots on some of the JM's.  I wouldn't be having this problem if I'd had daylight to be selective of the ones that were just collected when I was putting the trees in the greenhouse.  (...or if I hadn't been lazy and picked the others out when I did have daylight in the ensuing days).  The heater hasn't been on except for to keep the greenhouse above 28°F.  The greenhouse itself heats up in the sunlight and that's what has caused the issue (complicated by my inattention).

Regardless, I'll take a closer look and see if leaves are starting to form.  Thanks for the pointers.
 

rockm

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Re: Japanese Maple buds moving
« Reply #4 on: January 03, 2011, 01:55 PM »
Bill,

If those were mine, I'd pile about six inches of pine straw or shredded pine bark on them on the ground (making sure the pots were on bricks or something to allow dainage) and forget about them until spring.

Winter storage depends as much on keeping things cold (at an acceptable level) as keeping them "warm." I wouldn't be concerned about temps for unprotected plants until they got to about 15 F. I'm not too concerned about temps below 10 F with a heavy mulch covering on all my trees--Even then, I'm not too concerned, as even my collected Texas and La. trees have faced winters that have had single digit nights.

FWIW, here on the East Coast, we've had an extremely cold Dec. with deep freezes early. That means as Spring approaches, more plants will be fulfiling their "chilling hour" requirement earlier, which means the danger of early bud break may be more prevalent the closer we get to the end of winter.

I keep my maples and other deciduous in a shady spot all winter under eight inches of shredded mulch. This keeps them from warming up too much during warm spells..
 

elroyc

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Re: Japanese Maple buds moving
« Reply #5 on: January 03, 2011, 05:18 PM »

I keep my maples and other deciduous in a shady spot all winter under eight inches of shredded mulch. This keeps them from warming up too much during warm spells..

Do you have problems with mice or other rodents in the mulch?

Elroy
Ottawa, ON
 

bwaynef

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Re: Japanese Maple buds moving
« Reply #6 on: January 03, 2011, 05:39 PM »
Bill,
I assume you're talking to me.  I'm Wayne.
Quote
If those were mine, I'd pile about six inches of pine straw or shredded pine bark on them on the ground (making sure the pots were on bricks or something to allow dainage) and forget about them until spring.
So essentially, you're voting to let nature take its course (assuming they're not too far along yet, from your previous post).

Quote
Winter storage depends as much on keeping things cold (at an acceptable level) as keeping them "warm." I wouldn't be concerned about temps for unprotected plants until they got to about 15 F. I'm not too concerned about temps below 10 F with a heavy mulch covering on all my trees--Even then, I'm not too concerned, as even my collected Texas and La. trees have faced winters that have had single digit nights.

Ordinarily I don't take my trees off the bench.  Our winters just aren't that cold.  This problem started when I had recently dug japanese maples and was facing 16ºF lows for the better part of a week.

Quote
FWIW, here on the East Coast, we've had an extremely cold Dec. with deep freezes early. That means as Spring approaches, more plants will be fulfiling their "chilling hour" requirement earlier, which means the danger of early bud break may be more prevalent the closer we get to the end of winter.

I keep my maples and other deciduous in a shady spot all winter under eight inches of shredded mulch. This keeps them from warming up too much during warm spells..

That's interesting about the chilling hour requirement.  It makes sense and I've heard it before; just hadn't thought about how it would apply to this winter.
 

rockm

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Re: Japanese Maple buds moving
« Reply #7 on: January 04, 2011, 07:19 AM »
elroy,

I have not had a problem with mice. I suspect it's because my trees aren't enclosed in a cold frame---which could offer a more comfortable place for rodents to inhabit. We have a few predators around too, cats, owls and hawks...

Sorry Wayne, got confused with the psuedonyms...

I am advocating leaving things to nature. Sixteen degrees air temps aren't really that bad--provided you have protected the roots adequately--that's the whole issue with overwintering trees. If the newly collected trees' roots are protected under a heavy layer of covering, things should be OK, I'd think.

Chilling hours are tricky. If we get a cold early winter, the trees may fulfill their requirements early. Late winter warm spells can be trouble--but mulch tends to lag temperatures enough to prevent early bud break.
 

subnet_rx

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Re: Japanese Maple buds moving
« Reply #8 on: February 01, 2011, 12:27 PM »
Hi all, great thread, I'm a little concerned about the late freezes after buds break myself on my maples.  What temperature would accomplish killing the new growth after it's started?  32? 
 

rockm

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Re: Japanese Maple buds moving
« Reply #9 on: February 01, 2011, 03:53 PM »
Depends...If it's a frost, you will lose leaves and new shoots--which wil turn black over a few days and drop off. If the soil freezes through, you could lose the entire tree or large portions of limbs and trunks. Once buds "move" -- leaf edges visibly pull away from the bud--the tree has lost most, if not all, of its ability to withstand freezing temperatures. It's not the same as swelling--if buds remain "tight" but a bit plump, there is no danger.

The damage from a deepish freeze (below 32 for more than a few hours) is on sliding scale depending on how cold it got and how deeply that cold penetrated the root mass. Trees with more soil around their roots aren't as vulnerable, while those in smaller containers could be in dire danger.

If a tree is pushing growth and temps are forecast to be anywhere in the vicinity of freezing (In early spring I bring trees that have begun growing in if the forecast has nighttime temps near 37 or even 38) you should consider brining it inside until the freeze danger has passed. This can be a few days. Trees won't be harmed much if they're inside for that long. They will be harmed if left out in freezing weather and they have new growth.
 

subnet_rx

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Re: Japanese Maple buds moving
« Reply #10 on: February 01, 2011, 05:18 PM »
ok, thanks for the information and advice, that clears things up for me