JBP repot time and airlayering


(Jean MAssumi Hara) #1

Hi mr Dupuich and members of this forum

I was reading your posts about decandling by the 100th time,and you usually say that in warmer áreas we should decandle after cold áreas.Why did you get this approach?Cause here in Brasil,we usually repot a JBP on winter time.If we do on spring,its death for sure.So,all the procedures shouldn´t be earlier than ?
When you say warm area in USA,is it like Florida?
And if you can answer one more I like to ask if you do air layering on JBP.I bought one that has a great tip,but not good for the base.And I think its is a pity to loose that…
Thank you very much everybody.


(Jonas Dupuich) #2

Good question. By warm and cold, I’m referring to the difference between warm areas like Texas or Georgia and cooler areas like New Hampshire or Washington state. Because black pines grow more vigorously in warmer areas, we decandle later (July) as it’s easy for pines to produce good summer growth quickly. In cooler areas, pines need more time to develop good summer growth so we decandle there earlier (May).

I don’t have experience with black pines in tropical or sub-tropical climates. Roughly speaking, the time to decandle is after the spring growth hardens. As it’s warm where you are, decandling about a month after the spring growth hardens might be a good starting point, though I’d love to hear from anyone who has worked on pines in truly warmer areas like Florida or Hawaii.


(Jean MAssumi Hara) #3

Hi Mr Dupuich and members
Still pursuing a good way to develop healthy trees here…
Another question for you guys:The vigor of JBP summer growth is more related with warm temperatures all year long or the dormancy period in winter?Something like “cold winter and hot summer”.I dont know how much is necessary(or how long)to get the dormancy…but I´m sure that here in my area(southeast of Brasil),pines dont get it…i
t´s clearly a low performance comparing to temperate places,even with the same soil,watering and fertilizing…Thank you…


(Sely) #4

Temperature does effect root growth. For my understanding, dormancy occurs 2 times a year for me in Texas, winter and summer. During these 2 seasons roots do not grow, they only grow in spring and fall. Most of the time when I repot it’s late winter, meaning that roots are just waking up or just starting to grow- the white tips.
For some of us it could be late February or March, depending on cold climate zones to semi tropical zones. Most of us have to protect it from late freezes which can occur after winter into spring.
For grafting I must break the dormancy in a greenhouse in a much warmer temperature just to get sap flowing, which is about the time white root tips starts to show up.
So assuming that I was to live in Brasil, the lowest temperature in winter in some area might not even dip below freezing, but at that time should be perfect to repot because root production is at its minimum and it’s getting ready to warm up for faster growth.
As for air-layering, some people do it after the first flush of growth or even during winter, I tend to do mine during late summer because fall is the second season of root production but as for pines Muranaka bonsai a has several example on layering pines.
For dormancy, I think seeds needs at least 60 to 90 days so the I guess the tree itself needs it to. But I stratified mine in the top shelf of my refrigerator which is above freezing, I think it’s at 35 to 40f.


(Jonas Dupuich) #5

I also know people have grown black pine in Florida and Hawaii. It’d be great to hear how the trees grow there or if there are good learnings to share about their care in climates with little or no winter.


(Jean MAssumi Hara) #6

Thank you Sely and Jonas for the helpfull answer…
I was wondering myself if pines goes into dormancy in the summer time,but what about the second flush of growth?Isnt it indicate an active period of the plant fisiology?
Sorry for make all these questions ,but I really try to understand the plant behavior.
Ex:I never saw a JBP pine cone here…I guess they simply cant close the reproduction cycle …and maybe it happens because there is a lack of cold days in winter.
So do you guys think that we can have healthy trees here?Worth?
Thank you very much


(Sely) #7

The second flush is the remaining energy it has before dormancy starts. I don’t remember but I think root stops growing above 90 to 100f. Decandling is a way to force a flush, it’s the same thing as defoliating a maple in mid season. The plant try to recover it’s losses by producing more foliage from it’s reserves. So summer is a resting period after the growth and fertilization resumes again in fall to store more energy for spring.
Actually, the plant remains active throughout the whole year. Photosynthesis still occur through winter but slower. For deciduous, don’t quote me on this one but I think they are only active with foliage.


(Neli Stoyanova) #8

I am in Africa and have JBP for the third season now. I think they are doing well but I keep them in partial shade> 30% shade cloth. I think they like it better than full sun. I dont follow any month for decandling just look at the needles and decandle. Not sure if I am doing it right but so far they are OK and back budding very well. Mine are mostly mame and shohin.
I have learned never to decandle or cut weak branches or they will die.
some time I cut back to old needles if branch is long and they back bud well.