Questions on bending pines after cutting a wedge out of the trunk

[Noble]

I bought an 8' tall lodgepole pine (Pinus contortus) in a large plastic pot for $30 from a private seller about a year and a half ago. The trunk just above the base was about 4 inches in diameter. I was going to plant it in the front yard, but in the summer I noticed that it had a powdery orange blister rust infection starting about 4" up the trunk. The infected area was about 4 or 5 inches tall and wide. Upon reading that there was no cure for blister rust and that the tree would eventually die, I decided to try drastic measures and try some bonsai bending techniques on it. Late spring of this year I cut a wedge out of the trunk where it was about 3.5 inches across that completely took out the infected bark and wood, cutting through about 90% of the width of the trunk. Then I bent the trunk a full 90 degrees trying to connect the severed cambium layers, tied it in place, and sealed the wound with a Japanese cut paste. I trimmed the total height down to about 4 feet. I felt the operation went pretty well for my first attempt at doing this kind of severe bend, though some of the bark at the back of the bend did split. To my surprise, I didn't lose any of the numerous remaining branches above the bend, and they all put up candles that are still vigorous now in July. There has been no sign of the blister rust since I cut out the section. It has gone so well, that now I'm wanting to bend the trunk in two other places above the previous bend and really work on shaping the tree. I completely understand that the blister rust could, or likely will, return. So I'm torn between working more on the tree and destroying it to prevent spread of the disease. I have several smaller lodgepole pine that I'm trying to trunk up. But I don't have any fully developed lodgepole bonsai, so I'm only mildly concerned about spread of the blister rust, though I do have a black pine and mugo that I'm fond of, but I don't know about their vulnerability to this blister rust (I'm assuming it's the comandra blister rust that attacks lodgepole out here in the west). But, this seems like a good opportunity to try some radical bends on a fairly large trunk with not much to lose.

My questions: 1) When is the best time for doing these drastic bends after cutting wedges out of trunks? My late spring bend did well. Can I also attempt this in late summer or early fall to allow for some recovery before winter (Willamette Valley of Western Oregon, so mostly rain and little snow). 2) How many bends can I make on a trunk at one time using this method? Should I do one major bend and let it recover for a year before attempting another, or can I do more than one at once, or one in spring and one in fall?

I'm grateful for any any advice on either the bending technique or the blister rust.

Thanks.

 

[Shibui]

I have not done much of this wedge bending but from a purely plant point of view I would be reluctant to make more than 1 at a time. Reason being interruption to sap flow. Sap flows mostly in straight lines up and down the trunk. Tree can reroute sap to go round one major cut as sap can still pas through the unbroken section until the cut heals and re-establish sap path. making a second cut above and, presumably, on the opposite side will stop the sap flow from below and maybe the tree cannot compensate quickly enough. That's all theory rather than practice so please take it with the grains of salt it deserves.

This tree still has possible health issues so maybe use it as an extreme test case and try several bends. Success should be definitive but failure would not absolutely rule out the technique. We would need some more trials before considering it impossible.

 

[Noble]

@Shibui Thank you for the reply. Your answer about reluctance to attempt more than one of these severe bends with wedge cuts at a time is helpful. I was concerned about effectively girdling the tree if more than one wedge was cut at a time, but I thought there was a possibility of having the cambium layers being matched back together that might reduce that impact. Your reasoning about sap flow likely being able to be rerouted only around one cut makes sense. I will definitely try another bend, and perhaps another above where I'll likely want to chop the trunk later as an experiment. I just don't know how long to wait to let the previous cut heal. So I've not decided whether to try this fall or wait until spring.

 

[Potawatomi13]

Check if can be answered on Mirai Forum?

 

[leatherback]

Check if can be answered on Mirai Forum?

Bit of an odd recommendation on a forum.

 

[leatherback]

Take a look at other forms of bending. Instead of wedge cutting, look at hollowing out the core through a narrove slit instead. This will probably be easier on the tree. In the end, it is all about weakening the trunk so it will bend without breaking AND make it realistic to bend.

Naturally, pine is very limber, and when wrapped properly with raffia, big bends are possible on thick trunks taking enough time.

 

[Noble]

@leatherback Thank you for the recommendation on the technique of hollowing out the core through a narrow slit instead of cutting out a wedge. I have not used that technique, and it sounds like a viable option (I've only used trunk splitters for severe bends before). I used the wedge cutting technique on this particular tree specifically to completely remove the area infected with blister rust. And it went so well that I think I got focused on continuing with that technique when other options are possible. The hollowing technique sounds like it should, indeed, disturb less of the cambium and leave a smaller wound to heal. I have not seen this technique demonstrated. For very severe bends I would imagine that the bark would want to fold and split at the sides of the bend unless tightly wrapped with raffia.

 

[leatherback]

Keep in mind, you are doing massive surgery to the tree. Allowing a full year recovery before doing ANYTHING else is not an unreasonable approach. A friend of ming did a 160 degree bend on a big pine and waited 3 years for styling, so the tree was completely back to health

 

[Noble]

@leatherback Your recommendation to wait a year before any more work on the tree is really helpful. I had been thinking I might try another bend this Fall, but I'll heed your advice and wait until Spring, which will give the tree a full year of recovery from the first major bend. Thank you.