Heat damage to JWP

mapleman77

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I've read much of Brent's articles and they all seem to say (along with just about every other internet source) it's a bad idea to grow a Japanese White Pine in the deep south or any very hot area. Well, I'm in a hot, humid area and of course bought one. I've had it for a couple of months and am getting a little worried about the coming summer. It looks absolutely beautiful (not burn whatsoever) but I'm concerned that when the REAL summer hits, it'll sustain damage from sunburn and the roots overheating.

We've had about a week straight of low 90's and it took the sun just fine, I just kept it watered. It is not in direct sunlight but gets a little shade through the day. I also know that it'll get up to low 100's in the worst part of summer here.

What I guess I'm trying to ask to any person that's grown many JWP is, what is your experience with JWP as far as summer heat/sun damage? I don't think that I'm going to lose my 'Zuisho' JWP but I want to do everything to make sure that I'm never in that situation.

Thanks,
David

PS: Brent's solution to these problems is shade cloth. anyone had success with that as well?
 

greerhw

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I killed three in Oklahoma after everyone warned me they wouldn't live here (hard headed).
They live about three years and die a slow death, so I've yieded to mother nature, no more JWP.
Good luck with yours.

Ciao,
Harry
 

BUBBAFRGA

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Well, JWP is only pine i have kept alive except ones that come up in my pots from the long leaf trees in my back yard.

But it is a stick in pot....it was a seedling that I got three years ago. It is currently in a colander. I live in the DEEP south, 100 + degrees for weeks in the summer with 100% humitity. I move it under the magnolia trees toward end of May until it goes in the cold green house in October.

It will be another 20 years if it lives before it will be anything.
 

amkhalid

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Protecting it from the summer heat is one thing...

But the warmer winters might be the bigger issue... and harder to control for. Some trees just need that deep freeze.
 

mapleman77

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Thanks for the tips, guys. I feel that I can protect it enough from the summer heat and sun....but I've been (recently) more worried about the winter--i'm glad that you brought that up, amkhalid. It never gets THAT cold all of the way down here in LA...does 29 degrees F count? I think that was just about the lowest our winter got this year. Also, I think that duration might be more important than the actual temp, at least to some degree (no pun intended).

For now, it's in bright sunlight for most of the day and just enough shade. When it gets really hot i'll move it into more shade and go from there...but I have no idea what I'll do to try to get the amount of cold that the tree needs.
 

DaveV

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Mapleman77, I too have heard that it has more to due with the wintering of JWP. The summers where I live (iowa) gets very hot and humid as well, 90- 100 (with humidity) and mine seem to do just fine. I store them in my attached ,unheated garage in the winter and here it gets about 30 degrees all winter long ( the root ball actually freezes).
 

grouper52

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I have also heard that it is the failure to thrive due to lack or deep dormancy that slowly does them in, not the summer heat. Even in an area like the Puget Sound here - our summers are quite mild by the standards of most of the rest of the country, but our winters are not typically that cold - almost no one I know of messes with JWPs because they in variably fade away over time. They need a deep, dormancy-inducing winter cold. JBPs, OTOH, thrive here.
 

johng

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thoughts on JWP in the South

I have also heard what has been said about JWP. Here in South Carolina it gets as hot in the summer as it did where I grew up in Texas. Winters are also very mild...we may get some temps in the low 20 or upper teens but there is very little prolonged cold. I have had this tree for more than 8 year JWP are grown for nursersies...it has virtually the same latitude as Charlotte, NC..mild winters and steamy summers. I have also been maintaining a mame JWP since the 2005 World Bonsai show in DC...it does a little better every year. Here is a pic of the big one...I will try to remember to add a pic of the little one later today... I have other bonsai friends in the area that have had various JWP for nearly 20 years now and they are doing just fine.

In the heat of the summer my trees enjoy full morning sun but are protected in the afternoon.
 

mapleman77

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Maybe I should have named this thread "Cold Dormancy Requirements for JWP" because it seems that there is not a problem protecting them from the heat, the winter cold is the problem.

johng, you have a beautiful tree. Is yours grafted? I am starting to think that grafting JWP onto JBP rootstock might solve the winter dormancy requirements, since JBP does quite well down here. I'm going to start a batch of JBP seedlings next year and [hopefully] graft some JWP cvs. onto them. Also, it seems we have a very similar climate (steamy summers, mild winters). I'm hoping that my JWP will be ok because it is evident that yours is doing just fine.
 

greerhw

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Brain fart, maybe I will try one more time, clean out a spot in my wife's freezer and keep a shohin in there this winter........

Ciao,
Harry
 

amkhalid

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It never gets THAT cold all of the way down here in LA...does 29 degrees F count?

No, thats not very cold as a minimum :) I get some -25C days in winter and weeks of -10C easily from Dec-Feb. For you americans, thats like negative one million degrees fahrenheit (approximately). Things don't thaw, which is important. Brrr...

The trade off is we get to grow cedar, spruce, larch (amazing species... worth the cold) and things like JWP (a zone 4 tree) but they are hard to come by and very exotic/expensive so I don't really know many people who have them.

But you guys get to grow your share of cool trees which we could never grow. Over wintering in freezers is one option... I've heard some people taking extreme measures to overwinter larches down south. But the more complicated it is, the more things there are that could go wrong.

Good luck!
 
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It is the bud temperature for all tree's that require "chilling hour's", not root temperature. Most research has been done on fruit and nut tree's due to the cash crop value. You can find many that will require say, 1000 hours of temps below 45 per year. Some require more and some require less. I suspect that non cash crop tree's are the same way. Some conifers seem especially prone to this factor however my observations are lacking in this department.

My observations with some deciduous tree's around here are that if the bud's do not get their dormancy requirements met they will delay opening until they do. Sometimes this means a tree will not come out of dormancy untill as much as 6 weeks later than it did the year before. Over a period of several warm winters the tree can decline.

Deciduous tree's do not grow in the upper sub alpine zone. Only conifers grow here and I suspect the high alpine zone conifer may need an incredable amount of chilling hours, perhaps on the order of several thousand.
 
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rockm

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It's not really the cold, it's the heat

I've observed something related to this in the larch bonsai I've tried to keep here in the Middle Atlantic in Virginia.

Larch is native to more Northerly latitudes of North America in the cool bogs of New England, Michigan, New York and Canada. I'm within 60 miles of Larch's southern range here in N. Va., however. As a result, over the years, I've tried to keep larch bonsai, only to have them fade away over 5 or 6 years. They don't die all at once. They just show an overall decline in vigor. The slump starts showing up in summertime.

After killing two or three larches, I figured out it's not the cold--or the depth of the cold the tree experiences. We get adequate winter chill periods to satisfy other cold loving species like apple. The depth of the cold isn't really a factor, as trees can't really tell 32 degrees from 25 degrees. We get lows in the teens and single digits, which can persist for a week or so. It's not warm here in the winter.

It's the summer heat that kills larch here in Va. Larches are native to areas where nighttime temps drop below 70 degrees and the air is dry, allowing for temperatures to rise sharply in the day and drop off steeply at night--important for plants. Many plants depend on nighttime temperatures to be 10 to 15 degrees cooler than daytime temps to complete their photosynthetic cycle effectively. Humid summer air in the Southern US doesn't cool very rapidly and stays warm through the night and kills larches...
 

mapleman77

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What to believe, what to believe? There are many opinions it seems. For now I'm going to try to keep my JWP away fromsummer heat and sun but give it as much cold as I can. Hopefully it'll be enough.
 

meushi

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Well, JWP do fine in Osaka where the summer is stinky hot with 100% RH (with no temp drop at night) and the winter is mild and dry enough for me to go around in short sleeves most of the time. Maybe there is a factor other than the temperature?
 

meushi

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Osaka is in the Kansai area of Japan, close to Kyoto. 63F max (November during the day) down to 36F min (January during the night) is the normal range of temperatures for the winter. That is actually milder than spring here ;)
 

mapleman77

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Well, that is very encouraging! I wonder if you aren't right and another factor, say humidity or UV light strength is another issue.

As for now, my JWP is still looking fantastic. The needles are a deep blue-green and the white stripes are stunning. I want to keep it that way; I'm going to put it in some more shade as the summer continues on--it's getting hotter every week. Actually, it's been cool the past week because of rains and stuff, but it'll get up to high 90's, low 100's here during the summer. It'll get down to low 30's and MAYBE high 20's every once in a while during the winter. Maybe them Japanese have some secrets they need to tell. ;)

Anyway, do you have any JWP Meushi? If you do please post pictures for all to see! :D

David
 
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There are a few different varieties of white pine in range from the southwest desert to the high alpine zone to the there or over there further. It may be that all white pine or larch are not the same. Range of adaption to climate and all that. I'm still in the cold club. Also are we shure we are not getting blister rust? I have been strongly advised not to grow JWP by Brent because of the rust and lack of cold winter. He does recommend Pinus Strobis however. BTW I am under perpetual overcast all summer long with temps in the 60's.

Or maybe white guys cant grow white pine?:D
 
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