Bonsai Study Group Forum

General Category => Evergreen Bonsai Discussion => Topic started by: twigboy2000 on June 09, 2015, 12:24 PM

Title: Mugo pine dying buds
Post by: twigboy2000 on June 09, 2015, 12:24 PM
I've got a pretty healthy mugo except for 5 or 6 branch tips that have up and died.  Two weeks ago these were healthy.

I switched over to an organic spray this year (my wife is passionate about this so I have to sneak the good stuff when she's not around) and I'm wondering if it's mite damage.

Any ideas?

Title: Re: Mugo pine dying buds
Post by: 0soyoung on June 10, 2015, 12:57 AM
Assuming the buds aren't dry and fall off when you touch then, excise one of the affected tips, cut the bud and the nearby tip in half lengthwise, and let us know what you see. Anything green? Any little tunnels? Etc.
Title: Re: Mugo pine dying buds
Post by: twigboy2000 on June 10, 2015, 11:57 AM
I found one that was just starting to wither.  The inside is green and no sign of borers.

Title: Re: Mugo pine dying buds
Post by: 0soyoung on June 10, 2015, 01:18 PM
The basic issue is that these dying buds are not getting enough water - something is jamming the xylem. Borers eat some of the xylem. fungi can clog it, roots can quit supplying enough water, etc.

If I am understanding correctly, this is also progressive - the problem is getting worse and spreading through the tree (as opposed to the affected tips are the same, just those are drying up day by day)?

I assume you didn't repot recently (in which case, your tree doesn't have enough roots and you want to get it into some shade).

On the other hand, if the affected tips are on just one branch, I would consider removing that branch.
If it is just one of two or more tips of the same branch that are affected (i.e., the sibling tips are okay) I would consider removing just the affected tips (autopsy before tossy). More info ...
Title: Re: Mugo pine dying buds
Post by: twigboy2000 on June 11, 2015, 01:20 PM
So a little background for the more info part.

spring 2013 it was nursery material and transplanted into a training container with better soil.
fall 2013 I did a little bit of branch selection to thin out some over crowded areas.
2014 it was left to grow and fed/watered well.  Looked really healthy.
spring 2015 was repotted into a smaller container with a little root reduction (say 15%).

Initial bud break looked healthy and it was moved back into full sun in later May (early spring here in GA).

The bud dieback was mostly at the same time and affected maybe 10% of the tertiary branch tips.  It seemed to be onesie/twosie on each major branch and not a whole branch at a time.  The good news is that it's a project tree and still has several years of development and refinement ahead of it.  Once it's stable that is.

I had intended to move some of the leggier branches back around and approach graft them back in closer, but I think I'll wait another year and just feed/water it well again.

Oh, and I didn't think the spray was a problem.  I'm lucky if I get three regular applications in per year.  Day job and all...

Title: Re: Mugo pine dying buds
Post by: 0soyoung on June 11, 2015, 10:04 PM
I've always repotted mugos in August, well after all new growth is hardened. Even at that, I lost one after doing some light root work and returning it to the same (relatively) shallow pot that it had been in for the previous three years. It suddenly started getting that lifeless grey overtone in the needles, not long after the repot. I lost another that I dug from the grow bed this past August. Otherwise, I've not been the least bit careful about the roots and the mugos have thrived (6 various cultivars of various sizes). The only thing that I can identify to have possibly been the cause is being potted deeply in relatively shallow pots.

My suggestion is that you keep the pot tilted15 to 30 degrees and return it to shade for a little while. Once buds stop withering, or it seems healthy despite the buds not moving, return it to full sun, but continue keeping it tilted. As long as the needles stay their normal bright green, it will be okay. Mugo needles last about 5 years and you can normally prune all the new shoot (just like JBP candle pruning) after it has hardened for 3-4 years in a row (it will back bud strongly). So, not to worry about the buds - worry more about the needle color. This may well not be what your tree is suffering from, but it will do no harm if I am wrong.

The catch-22 about root issues is that there is insufficient capacity to supply the foliage, so the foliage doesn't conduct as much photosynthesis, but this means lowered food/material and stimulus for root growth. So we must reduce the transpirational stress (shade and/or humidity tent) to get the foliage working, which then gets the roots growing, etc., etc.

Meanwhile, investigate the possibilities that pathogens involved further. Maybe someone else who has dealt with trouble similar to what your tree is experiencing will offer some insight into what is actually going on with your mugo.
Title: Re: Mugo pine dying buds
Post by: Owen Reich on June 12, 2015, 10:37 AM
Mugos have not always performed well in GA (I'm from Acworth).  They don't particularly like the mild winters or high humidity.  You may be better off focusing on other pine species.  By no means should you give up on this one.  Just something to consider.

I've seen and heard about a number of Mugos living for 3-5 years in GA, then dying or slowly declining.
Title: Re: Mugo pine dying buds
Post by: twigboy2000 on June 12, 2015, 08:43 PM
Thanks Owen,

It's the only one I have and it was a well meant gift.  I'm trying to make the best of it.  At the very least, I'm learning some things.  My other pines are JBP and a few natives (loblolly, virginia).  Everything else is really healthy despite fighting off some needle cast on one last year.

Title: Re: Mugo pine dying buds
Post by: 0soyoung on June 13, 2015, 08:23 PM
One more thought, twigboy.

Tree roots stop growing at temperatures around 95F (and above). You might stick a meat thermometer (steal the one from your kitchen - sterilize with alcohol and wash afterward - or buy one for less than $15 at the grocery/hardware store) at various points in the soil around the pot. Do whatever you can to keep the roots below 85F. A light colored wet towel can be wrapped around the pot and cover the soil surface to reduce solar heating and to effectively make a swamp cooler, for example. As long as your air temps aren't much over 95F, I think it will be best to keep it in full sun, but you may need to seek some shade in order to keep the roots cool, anyway.

Keep us posted.
Title: Re: Mugo pine dying buds
Post by: M. Frary on May 05, 2016, 03:22 PM
  Sounds like it may be going zombie. Not alive yet not dead. It happens if you mess with mugo roots in the spring. I had one do it and Vance has seen it too. If it doesn't die outright this year there is hope it will grow next year.
  This is not me joking. Zombie mugos are real.
Title: Re: Mugo pine dying buds
Post by: scereghino on January 16, 2017, 10:19 AM
Any update? I have been thinking about this and my guess is you don't get a lot of cold weather in Georgia. The Swiss Alps are very cold. esp up high where the mugos grow. I remember it being -10°F in town. It can be humid in the summers in the Alps but winds do dry out the peaks a little.
So my guess/assumption is the tree is not getting its natural winterization.
I have heard many folks repot in the late summer, I do so in the spring, more lime late winter (March) here in California.  My reasoning is we have 100°F days in Aug and Sept with little humidity. But...... I am also super cautious and only root prune 20% at a time.
Title: Re: Mugo pine dying buds
Post by: twigboy2000 on February 03, 2017, 03:39 PM
Here's a little update on this guy.

We had a very hot and very dry summer/fall in GA last year.  I think we were at drought conditions for part of the year.  I ended up moving this guy under some shade cloth and it seemed to do a little bit better.  All in all, I think I lost maybe 10% of the branch tips.

This year the plan is to just water and feed and not mess with it too much until I see noticeable vigor.  Then maybe I'll work some of the leggy branches back in and approach graft some buds closer in to the trunk.

Thanks for the interest,
Title: Re: Mugo pine dying buds
Post by: VanceWood on March 28, 2017, 09:25 AM
From your pictures I do not see evidence that the tree is in trouble.  There is a weevil that lays eggs in the unopened buds that can cause this. Just leave the tree alone for a while and give it a chance to grow.  As to grafting I don't do grafting on Mugos and grow a lot them. 
Title: Re: Mugo pine dying buds
Post by: bwaynef on April 14, 2017, 08:26 AM
As to grafting I don't do grafting on Mugos and grow a lot them. 

Is that because they bud so readily you don't find it necessary, or because you've managed to work around it in your designs?
Title: Re: Mugo pine dying buds
Post by: VanceWood on August 09, 2018, 08:17 PM
I have never found it necessary.  I have had to simply concentrate on keeping the growth toward the center of the tree making grafting unnecessary.  In all honesty I am not very good at grafting and I avoid it at all costs.