Juniper problems and dormancy in regards to different parts of the country

[october]

What has prompted me to post this is actually seeing the health of cascade's (Dorothy) junipers. The health of her trees reminded me of how my junipers, as well as junipers at the nurseries here in the northeast, used to look up until about 4 years ago. This will be an open discussion about the health of junipers in regards to dormancy in different parts of the country.

It has become well know that in the last 3-5 years, here in the Northeast, we are having quite a few problems with junipers. Not only bonsai, but landscape junipers as well. Junipers are just not flourishing like they used to. There are fungal diseases, scale, mites and other problems which are not that clear as to what is causing them. For me, the last 2 years have been pretty bad. I am finally getting things back on track. I never had juniper problems until about 3 years ago.

Also, as mentioned, it is not just bonsai. I went to a local nursery during the summer. About 50% - 60% of their junipers were decimated, brown, pale and completely lacking vigor. Our winters around here can have quite the swing. A few years back, we had a winter where half of it was in the 50's, actually hovering around 60 degrees F. Last winter we had temps in the low teens and single digits with wind chills below 0.

What I am looking for are temp ranges and how people more toward or in the south keep their junipers. Especially cascade (Dorothy) or other people with very healthy junipers in the South Or West or in between.

Dorothy.. If you would be so kind as to share how and where you keep your junipers in winter. What are the temp ranges and how much sun, if any, do they receive. Also, do they go completely dormant like around here. I am wondering if the situation of one winter being mostly in the 50's, then the next in the single digits and teens, might be taking a toll on the junipers in the Northeast. I have thought of maybe, some how, doing a looser dormancy. Sort of mimicking the care they would get in Florida or surrounding states.

It seems like every other week for the past year or 2. Someone comes on with a juniper problem. Just want to do everything to try to resolve these on going issues for everyone having problems.

Rob

 

[jkd2572]

We have very mild winters down here and my junipers look great. My problem is spider mites. I don't wait for a problem to happen anymore. I spray my junipers once a month with pesticide. I find that once I discovered a spider mite problem it can take up to two years for the juniper to regain its health. Nasty little guys.

 

[october]

We have very mild winters down here and my junipers look great. My problem is spider mites. I don't wait for a problem to happen anymore. I spray my junipers once a month with pesticide. I find that once I discovered a spider mite problem it can take up to two years for the juniper to regain its health. Nasty little guys.

This year was the first year I had spider mite damage. However, I found it immediately and no real damage occurred with the exception of a few tufts of pale foliage that are not even visible.

I am starting to think that maybe some of the junipers are not as equipped to deal with extremes, especially cold. It could be that much of the quality junipers come from California and sometimes Florida. They make their may around here and may do ok for a couple of years, then they start to decline. Of course, this is just a theory.

I am seriously considering giving them sun during the winter and not exposing them to long periods of below freezing temperatures.

Rob

 

[Dav4]

Rob, do you really think it's the winter cold? The last two winters were exceedingly mild to the point it's almost funny to think about it. Honestly, when was the last time you remember the temps in your neck of the wood approaching or falling below zero F(most of Bristol County MA should be classified as zone 6, so expected winter lows SHOULD fall below zero every year.

I have some trees that go back to the winter of 1999-2000, when my daughter was born. The day she came home from the hospital, the day time highs didn't reach 20 f....the next 10 days or so were equally chilly with night time lows between 0 F and -8 F and daytime highs barely making it into the low 20's F. My trees, overwintered in my yard or unattached garage, did fine then, and continued to do fine, mostly, until I moved to GA 4 years ago. Since then, I have had some issues with my junipers, mainly mites and apple cedar rust.

I've done a lot of thinking about this and I suspect it's a combination of issues at work, mainly regionality and horticulture. By regionality, I mean that I suspect mites and rusts are just a bit more common in the SE USA, and so my trees are more likely to be exposed to them. Horticulturally, I do my best but it's not ideal by a long shot. My property is heavily wooded and on a steep incline, so I basically have had to cram all my trees into the one part of my back yard that gets appreciable sun, terrace style with one set of shelves almost directly behind and above the other. The trees are crammed together, and at best, get 4 hours of midday sun a day. So we have sub optimal sun exposure, AND less then optimal ventilation, which I am beginning to feel is more significant then anything else when considering pests and their impact on the trees.

So what does this mean...I honestly don't know....but I suspect that I'm onto something concerning my yard's foibles (and the subsequent horticultural shortcomings it creates) and the relative increase in disease my junipers have had. I am actually planning on removing a few trees to add maybe another hour of morning light. I'm going to spend the winter examining options on spreading the shelves out more to improve ventilation while still getting adequate light for the trees. My trees stay out on the benches year round and that won't change. Junipers are EXTREMELY cold hardy and I don't even consider doing anything unless temps are falling below 20 F and the forecast for the next few days will be equally cold...then they MIGHT get placed on the ground. Mind you, the first two winters down here, the temps fell into the single digits...the last two winters the temps barely fell below 25 F....the difference in cold didn't seem to affect the trees for good or for bad.

I guess my only suggestion for you would be to really step back and look at how you maintain your trees, both in summer and winter, and analyze them objectively. I think it's very easy to become complacent and assume that since you've been doing something without issue for a long time that you're doing it all just right. With that said, if you're still overwintering your trees inside the cold room, I'd really look at the ventilation, or lack there of, that may be at work there. Good luck with your junipers, as they're some of the best we see here.

Dave

 

[october]

Rob, do you really think it's the winter cold? The last two winters were exceedingly mild to the point it's almost funny to think about it. Honestly, when was the last time you remember the temps in your neck of the wood approaching or falling below zero F(most of Bristol County MA should be classified as zone 6, so expected winter lows SHOULD fall below zero every year.

I have some trees that go back to the winter of 1999-2000, when my daughter was born. The day she came home from the hospital, the day time highs didn't reach 20 f....the next 10 days or so were equally chilly with night time lows between 0 F and -8 F and daytime highs barely making it into the low 20's F. My trees, overwintered in my yard or unattached garage, did fine then, and continued to do fine, mostly, until I moved to GA 4 years ago. Since then, I have had some issues with my junipers, mainly mites and apple cedar rust.

I've done a lot of thinking about this and I suspect it's a combination of issues at work, mainly regionality and horticulture. By regionality, I mean that I suspect mites and rusts are just a bit more common in the SE USA, and so my trees are more likely to be exposed to them. Horticulturally, I do my best but it's not ideal by a long shot. My property is heavily wooded and on a steep incline, so I basically have had to cram all my trees into the one part of my back yard that gets appreciable sun, terrace style with one set of shelves almost directly behind and above the other. The trees are crammed together, and at best, get 4 hours of midday sun a day. So we have sub optimal sun exposure, AND less then optimal ventilation, which I am beginning to feel is more significant then anything else when considering pests and their impact on the trees.

So what does this mean...I honestly don't know....but I suspect that I'm onto something concerning my yard's foibles (and the subsequent horticultural shortcomings it creates) and the relative increase in disease my junipers have had. I am actually planning on removing a few trees to add maybe another hour of morning light. I'm going to spend the winter examining options on spreading the shelves out more to improve ventilation while still getting adequate light for the trees. My trees stay out on the benches year round and that won't change. Junipers are EXTREMELY cold hardy and I don't even consider doing anything unless temps are falling below 20 F and the forecast for the next few days will be equally cold...then they MIGHT get placed on the ground. Mind you, the first two winters down here, the temps fell into the single digits...the last two winters the temps barely fell below 25 F....the difference in cold didn't seem to affect the trees for good or for bad.

I guess my only suggestion for you would be to really step back and look at how you maintain your trees, both in summer and winter, and analyze them objectively. I think it's very easy to become complacent and assume that since you've been doing something without issue for a long time that you're doing it all just right. With that said, if you're still overwintering your trees inside the cold room, I'd really look at the ventilation, or lack there of, that may be at work there. Good luck with your junipers, as they're some of the best we see here.

Dave

Thanks Dave, I don't do the cold room thing anymore. Winters are too crazy. I realize that too warm in winter has it's affects. The room I used to use is not longer acceptable due to certain winters getting up near 60's for half the winter. In fact, as far as fungal issues, that started after the warm winter 2-3 years ago. So that part, I might have that problem solved. The trees are now wintered in a shed in the yard. All in all, things are doing better, some are looking pretty good again. It's just something that I am not willing to go through again. It was seeing how healthy Dorothy's junipers are that made me wonder how much cold they are exposed to in Florida.

Also, there is another thing. My trees are small. Remember they are only 6-12 inches in height so you know how small the pots are. Also, I know that John Romano now has a green house that he winters most of his trees in.

As stated, it really seems like it has been an on going problem. Like the landscape nursery near where I live. Many of the junipers were decimated. Also, the season I worked at the bonsai nursery. You had already left at that point. Many of the junipers were losing foliage at an alarming rate.

Rob

 

[Dav4]

Yeah, if I had to pick a perfect overwintering scenario for junipers, it would be daytime highs in the 50s F and night time lows in the mid to low 30s F...with lots of sun. The increase in temps without the increase in sunlight just isn't good as the trees will be more metabolically active and need that sunlight for energy. I suspect that's why the FL junipers look so good...their dormancy is short but adequate and they stay metabolically active and growing for most of the year. In the northern half of the country, you just can't do that without a really nice green house with excellent heating and ventilation control.

 

[october]

Yeah, if I had to pick a perfect overwintering scenario, it would be daytime highs around 50 F and night time lows in the mid to low 30s F...with lots of sun. The increase in temps without the increase in sunlight just isn't good. I suspect that's why the FL junipers look so good...their dormancy is short but adequate and they stay metabolically active for most of the year. In the northern half of the country, you just can't do that without a really nice green house with excellent heating and ventilation control.

Yes, I completely agree with what you just said. I am waiting for Dorothy's response to find out just how much dormancy her junipers get.

Rob

 

[cascade]

Yes, I completely agree with what you just said. I am waiting for Dorothy's response to find out just how much dormancy her junipers get.

Rob

Rob,

I do not get much winter down here. Usually the nights will be in the 50's and then dip into the 40's now and then ( about 44/45 ). Once in a great while we will go down into the upper '30s, but only for a few days in a row. Rarely will we have frost that lasts more than a few hours.

Here is my thoughts about the junipers I grow: I do not think my junipers are getting enough of a winter break. How I know? Whenever I got junipers from up North, New York State, North Carolina (San Jose junipers), they were never as vigorous as the year they arrived in Florida! Color and smell tells me all about the health of a tree.
I recall there was a problem with a fungus on juniper a few years ago. That may have been the reason for the decline you are mentioning?
Also, down here one has to already choose the right material to begin with depending on what your plan is with the tree. For a full nice green canopy you want a younger vigerous tree. For a tree with deadwood ( jins, shari) I prefer to work on already older jin beaten material. It saves me time and headaches.
This leads to one of the most important aspects of why folks down here seems to have problems with junipers as well. They overwork their trees. Constant pinching of junipers will weaken them and eventually kill them. The trees need to be planted in good soil. A solid repotting including the correct removal of the old soil ( over time sometimes) seems crucial.
Regarding the light during winter months, my junipers remain in the same locations. I actually move them more into the sun. During the hot summer months I will protect them from getting sunburned ( No, not due to watering ( myth) but due to direct hot sunlight).
I do not have a mite problem. I wash my trees almost every day with the water hose and make sure the sun gets into the interior.They get plenty of fertilizer and water. And I mean water.

I do not remove too much foliage or lifeveins at a time, and I do not transplant during wintermonths. I repot by beginning of March. I do not pinch junipers, unless I am planning to photograph or to show them. I shorten individual shoots in spring and in fall. The strong tips in spring and the sideshoots in fall. Procumbens will keep their mature foliage that way. That's just how it works for my trees in my backyard.

Best, Dorothy

 

[october]

Rob,

I do not get much winter down here. Usually the nights will be in the 50's and then dip into the 40's now and then ( about 44/45 ). Once in a great while we will go down into the upper '30s, but only for a few days in a row. Rarely will we have frost that lasts more than a few hours.

Here is my thoughts about the junipers I grow: I do not think my junipers are getting enough of a winter break. How I know? Whenever I got junipers from up North, New York State, North Carolina (San Jose junipers), they were never as vigorous as the year they arrived in Florida! Color and smell tells me all about the health of a tree.
I recall there was a problem with a fungus on juniper a few years ago. That may have been the reason for the decline you are mentioning?
Also, down here one has to already choose the right material to begin with depending on what your plan is with the tree. For a full nice green canopy you want a younger vigerous tree. For a tree with deadwood ( jins, shari) I prefer to work on already older jin beaten material. It saves me time and headaches.
This leads to one of the most important aspects of why folks down here seems to have problems with junipers as well. They overwork their trees. Constant pinching of junipers will weaken them and eventually kill them. The trees need to be planted in good soil. A solid repotting including the correct removal of the old soil ( over time sometimes) seems crucial.
Regarding the light during winter months, my junipers remain in the same locations. I actually move them more into the sun. During the hot summer months I will protect them from getting sunburned ( No, not due to watering ( myth) but due to direct hot sunlight).
I do not have a mite problem. I wash my trees almost every day with the water hose and make sure the sun gets into the interior.They get plenty of fertilizer and water. And I mean water.

I do not remove too much foliage or lifeveins at a time, and I do not transplant during wintermonths. I repot by beginning of March. I do not pinch junipers, unless I am planning to photograph or to show them. I shorten individual shoots in spring and in fall. The strong tips in spring and the sideshoots in fall. Procumbens will keep their mature foliage that way. That's just how it works for my trees in my backyard.

Best, Dorothy

Thank you Dorothy. We are kind of in similar boats with opposite ends. You get junipers from up North and they tend not to be too vigorous or getting enough dormancy. I get junipers from California and maybe Florida and they are subject to some pretty harsh winters here.

Your junipers are truly some of the healthiest ones I have seen on the forums. Whatever you are doing, even lack of full dormancy, seems to be working really well.

Rob

 

[ABCarve]

Yeah, if I had to pick a perfect overwintering scenario for junipers, it would be daytime highs in the 50s F and night time lows in the mid to low 30s F...with lots of sun. The increase in temps without the increase in sunlight just isn't good as the trees will be more metabolically active and need that sunlight for energy. I suspect that's why the FL junipers look so good...their dormancy is short but adequate and they stay metabolically active and growing for most of the year. In the northern half of the country, you just can't do that without a really nice green house with excellent heating and ventilation control.

The first bonsai (proc. nana)I purchased, I gave to my mother. It was 20+ years and very healthy...came from a teacher. My mother kept it in her unheated, glassed-in, back porch for the winter. It never froze and received mostly southern light. It could reach 50-60 deg. on a nice day. It always looked fowl...poor color...very little growth (even in summer). After 22 year of this treatment she gave it back to me as she didn't want to take care of it anymore (she's 87). I've had it 3 years now and I put it outside, unburied against my heated barns leeward wall in our bad winters. It has recovered and is doing very well. To me, it seems the full dormancy brought it back. I have had no problems with any juni I have and the nurserys around here seem the same.

 

[ABCarve]

The only problem I've had is an unheated garage that I store more tender stuff. Three of the four walls are heated. In the spring junis had brown tips and later in summer would have die back. Could not figure it out, until I noticed the die back was always on the side stored against the heated wall. It took me 20 years to figure this out and I blame this for most of my loses of trees. They died a very slow death. I now leave the garge door cracked and use it a a thermstat. No problems now.

 

[october]

The first bonsai (proc. nana)I purchased, I gave to my mother. It was 20+ years and very healthy...came from a teacher. My mother kept it in her unheated, glassed-in, back porch for the winter. It never froze and received mostly southern light. It could reach 50-60 deg. on a nice day. It always looked fowl...poor color...very little growth (even in summer). After 22 year of this treatment she gave it back to me as she didn't want to take care of it anymore (she's 87). I've had it 3 years now and I put it outside, unburied against my heated barns leeward wall in our bad winters. It has recovered and is doing very well. To me, it seems the full dormancy brought it back. I have had no problems with any juni I have and the nurserys around here seem the same.

Hi ABC. This is interesting. I am surprised that the tree lasted for 22 years in conditions that kept it in mediocre health. Usually after about 3-5 years, the tree dies. Also, do you think that other factors may have played a hand in it. For example, maybe not a good fertilizing, watering regimens or just not as much attention in general as it is getting with you. I have no doubt now that it is in your care it is doing better. I believe that your wintering has helped, but I also think your attention to watering, fertilizing and the other seasonal requirements are also helping.

The point of this thread was that I was interested in the wintering of junipers in different parts of the country and wanted to gauge the health of these junipers. I realize that there are many factors involved other than over wintering. Of course, junipers do grow best when given a winter where the majority of that winter in the 30's. I am just curious as to junipers in warmer climate and their health, as Dorothy's are in outstanding health in Florida.

Rob

 

[ABCarve]

Hi ABC. This is interesting. I am surprised that the tree lasted for 22 years in conditions that kept it in mediocre health. Usually after about 3-5 years, the tree dies. Also, do you think that other factors may have played a hand in it. For example, maybe not a good fertilizing, watering regimens or just not as much attention in general as it is getting with you. I have no doubt now that it is in your care it is doing better. I believe that your wintering has helped, but I also think your attention to watering, fertilizing and the other seasonal requirements are also helping.

The point of this thread was that I was interested in the wintering of junipers in different parts of the country and wanted to gauge the health of these junipers. I realize that there are many factors involved other than over wintering. Of course, junipers do grow best when given a winter where the majority of that winter in the 30's. I am just curious as to junipers in warmer climate and their health, as Dorothy's are in outstanding health in Florida.

Rob

I understand you're point but my mother was very vigilant...I made a point of it. I don't understand how it made it this far myself.

 

[MACH5]

I only keep RMJs in my collection so I can't speak for other varieties. For RMJs I have never given them any winter protection whatsoever except placing them low by a half wall I have to protect them a bit form the blast of cold drying winds. They have done very well in these conditions in the North East. I am often more worried about pots cracking than the actual tree itself.

The only time I will give them protection in an unheated garage is if the tree has been recently wired and styled.

I also had one large Hollywood juniper that I kept in the same conditions for many years with no problems either.

I do, from time to time, get a fungus due to high humidity or prolonged rainy periods in the Spring/Summer, but I have been able to easily control it with a copper based fungicide.

 

[ABCarve]

Florida gets more daylight being further south.

 

[october]

I think we can agree that here in the northeast, we might gain some benefit if the growing season was longer. It is not a cold issue, but the time frame could be improved.

Here is my scenario. Around here, temps can still be in the 40's right before or even into June. Now, I live somewhat near the water, it is actually colder, mostly due to wind at my house. People are amazed that just a few towns over, their temps are sometimes close to 10 degrees warmer than at my house and no wind. My junipers tend to not get going until later in the season. This year, due to the prolonged cold and repottings of several of them. They really did not start growing vigorously until August. That's right, August. Sometimes we get out first frost in October. Sometimes we have temps near 70 degrees F going into November. It is always changing. As far as this year. It appears my junipers are only going to enjoy about 2 1/2 months of good growing. This does not give them a lot of strength going into Winter. All in all, we make do with what we have.

Rob

 

[Dav4]

Rob, fwiw, my shimpakus, Hollywood and san jose junipers all seem to grow with more vigor and develop faster here in N. GA. when compared SE MA, and it must be our somewhat warmer springs and falls. Today will be 90 F, above the average, but temps will fall back into the low 80's and upper 70's later this week, and they'll stay there for a while. The junipers won't grow like they did in April, but they'll keep filling in for another 6 weeks or so, at least.

The RMJs do fine but don't seem to grow AS fast as they might have in MA...this may be more of a factor with their current stage of development then anything else. Hmmmm...I clearly need another raw RMJ that's completely unstyled to experiment with.....

 

[MACH5]

I think we can agree that here in the northeast, we might gain some benefit if the growing season was longer. It is not a cold issue, but the time frame could be improved.

Here is my scenario. Around here, temps can still be in the 40's right before or even into June. Now, I live somewhat near the water, it is actually colder, mostly due to wind at my house. People are amazed that just a few towns over, their temps are sometimes close to 10 degrees warmer than at my house and no wind. My junipers tend to not get going until later in the season. This year, due to the prolonged cold and repottings of several of them. They really did not start growing vigorously until August. That's right, August. Sometimes we get out first frost in October. Sometimes we have temps near 70 degrees F going into November. It is always changing. As far as this year. It appears my junipers are only going to enjoy about 2 1/2 months of good growing. This does not give them a lot of strength going into Winter. All in all, we make do with what we have.

Rob

Yes this is very true. My junipers did the same. They did not really get going until about July. Now they are in full swing and growing nicely.


Perhaps with species like RMJ that are from colder climates this is not so much of an issue going into Winter as much as others from warmer climates that may need a longer growing season?

 

[Brian Van Fleet]

Hmmmm...I clearly need another raw RMJ that's completely unstyled to experiment with.....

We should talk...particularly around November 1...

 

[Dav4]

We should talk...particularly around November 1...

Hmmm, yes we should......don't tell my wife, though.