Hello, all. To fix some rabbit damage to a pear tree that was girdled 50%-60%, I am going to try bridge grafting 2-3 branches in the hope it’ll help the tree fully recover. Doing some research on bridge grafting, I see there is a ton of conflicting guidance so I thought I would create a new post with some outstanding questions.
My plan is to: (1) clean up the area, (2) apply Tanglefoot Tree Wound Pruning Sealer & Grafting compound to the girdled area; (3) install 2-3 grafts; and (4) wrap the grafts with electrical tape/tree plastic.
Can I do this now when the tree is fully leafed out?
Are the above steps correct? Anything to add?
How deep do I cut into the tree for the bridges?
When selecting scions for the bridges, May I select any new growth on the tree?
I assume I remove any leaves on the bridge scion?
Any good videos on this? This is the first time in endeavoring to graft anything so I’m anxious about doing more harm…
As always, thank you for the thought guidance/insight!
Thanks, @no07. I didn’t realize it had to be dormant scions. the tree is fully leafed out currently. So, I may just let it go for now. Generally speaking, is there anything I can do for the wound/tree to help it heal faster? For example, can I still apply the Tanglefoot sealant?
Trim the edges of the wound (at the transition of the wood into the bark) with a sharp knife or chisel so that you get a smooth, flat surface for better healing (also, the rest of the wound) and coat everything with the compound you mentioned.
What I would do ….
First I would remove that wire from around tree , it will girdle it.
Use something soft , like a old shirt , or cloth strips around trunk if it need support.
Then remove loose bark .
Check with a knife , if there is any green cambium left in the damaged area. Some times they don’t eat it all down to wood.
With luck there is still cambium enough to heal.
If not ,? … I would trim the boarder back to a nice smooth edge , all the way around with a knife ,so It will heal better.
If the verified damaged area with out cambium is more than 1/3 the way around I would try bridge grafting , useing straight scion from last years growth to bridge graft. Cut those scions ,now , it’s worth a shot ,remove all leafs immediately wrap with parafilm , do essentially a bark graft sticking them under the bark ,top and bottom ,cut them a little long, use 2-3.
Use a small wire nail at top and bottom to secure them. Wax over graft.
Save a couple of the shoots growing from below the damage , they will give you a good second chance to bridge next year, or maybe in August , if this year’s attempt fail .
You ask how deep to cut into tree ? A bridge graft (and bark grafts ) are a sharpened scion slid under the bark , between the wood and bark .
I have fixed many trees this way .
A few suggestions, with the caveat that I have a very poor track record with bridge grafts.
Don’t underestimate the ability of a tree, especially an apple, to heal. I’ve had ones that looked far worse that pulled through just fine, including a couple that I thought were 100% completely girdled. Apples are pretty forking tough. I think most of my bridge graft attempts have caused more damage than they’ve repaired.
I’d tend to disagree with the need for dormant scions. You’re not counting on the buds in any way, so essentially the scion is providing phloem to help keep the top of the tree supplied with water and nutrients from the roots. I’d think vigorous one year old wood should be ideal, dormant or not.
Not sure if your steps were meant to be sequential, but save the tanglefoot for last
JMHO…on a tree that young with that much remaining growth above the graft, I wouldn’t try bridge grafting. I’d either let it go as is and see what happens, or just cut it off below the damage and let it regrow a new leader. Ya, you’ll lose a year or two but you’ll still have the desired variety.
@smsmith i may try to let it recover and hope for the best. I’d rather not cut before the damage because it is fairly low (although still above the graft). Should I still clean the wound and cover with the Tanglefoot wound sealant?
Also, and for reference, it is a young tree, but is about 7 feet tall and 4 feet wide. So it is fairly well branched and a nice size.
I wouldn’t cut it either until you know whether or not it may survive as is. If the tree pushes new growth below the damage, I’ll allow it to grow until next spring. You may not know if the top will survive long term until this time next spring.
If there’s any loose bark, I’d remove it with a sharp knife. I personally do not subscribe to the idea of covering wounds like that with sealant.
I understand not wanting to lose your 7’x4’ tree. Get it and all the others protected with aluminum window screen material or hardware cloth. I’ve had rabbits damage trees during the summer as well. Live and learn.
I don’t mean to negate everything no07 said (oops) but my feeling on trimming is again best to leave well enough alone.
I had a number of apples girdled (I see now that your tree is a pear) in 2021, and thought them a total loss. The worst, a dwarf weeping crab I’d found and grafted into the orchard, had no visible bark on the bottom 16” or so of trunk. I did several bridge grafts (all failed) yet my tree is living today, and barely skipped a beat. The summer after the girdling, we had high heat and extended drought to boot.
Worst vole damage I’ve seen. I thought it couldn’t live:
Here’s what my bridge grafts looked like in case you want to try it. Though mine didn’t take l, so maybe don’t copy my technique! I graft all sorts of things BTW, not sure why these tend not to work for me.
None of these trees show any sign of having slowed down particularly. The dwarf crab (which makes 1” diameter fruit) made a HUGE crop of little apples that year. I was shocked when they ripened, and even more shocked when the tree leafed out the next year and did it again. One of the others is a golden russet. It bore well too. Amazing the fruit load these girdled trees could support, but then it’s apparent to me that even though there wasn’t bark there (and no sign of green) there was still enough tissue there to callus and heal. Probably there was phloem at least (so the tree top was getting water and nutrients through the wound. Possibly some xylem too.
I think any tissue that’s in place has already callused and can only help to cover the wound quicker. My personal take FWIW. Opinions would vary though.
Here’s the bridge graft tree in the pics. I removed the failed graft this spring. You can see the remnants of the wound from the graft thoigh. Note how the edges of the girdle wound enlarged themselves to compensate and help wall off the damaged area. Trees are smart cookies, and a lot tougher than most people realize.
I totally agree that new growth flexible scions with buds trimmed off would be far better than stiff dormant scions which are not going to bend enough to do the insertions under the bark on each end. As you say all you need is compatible new wood that has fresh Phloem to do the job!