It's winter and we all have the lurgy. Old injuries are playing up, infections are up and about, waving their sickly tendrils. The slings and arrows are harder at this time of year. The wind bites, storms knock, rain drenches. The cold gets everywhere. Most years, trees would be sleeping aroundabout now. But this weekend I had to grit my teeth and do my winter prune in the warm, hoping that not too much sap was rising...
The early trees, the Service Bush and the Winter Cherry, already have swollen buds. The terrible insect damage on the Service Bush has crusted around with woody overgrowth. It's now been two years since the final demise of the beetle grub and the damaged stem is not only still alive, it's thriving. I never took any action to repair the plant, even though the grub left a nasty mess. There was so little to work with; the stem was the thickness of a pool cue, and the bark layer on a Mespilus is so thin, and the heart wood was thinner than a pencil, and full of dead beetle and frass.
The tree response to wounding is not to heal. Instead it compartmentalises the injury by growing healthy, new wood around the injury site, eventually covering it over with new growth. The injury remains, entombed and enrobed in a flood of new, healthy wood. Barrier zones within the transport cells (the famous xylem and phloem) prevent passage of pathogens and decay bacteria from the wounded area to the healthy wood. The wound is steadily brought inside the tree, stabilized, covered over. Cavities may be compartmentalised or flooded with new wood, depending on their size and location. This all takes time.
While I was finding this out, I discovered an internet full of American online guides about how to save damaged trees, and lots of British ones about how to hold people or organisations liable for damage caused by trees. Different perspectives, trees and damage.
There is a technique practised by arboriculturists called scribing, where the damage to the tree is tidied, bark trimmed to a smooth oval, the injury cleaned and made tidy. I didn't do this to my tree. I left the ragged edges to heal on their own. I find myself wondering if this is not something more done by and for the human caring for the tree, to indicate that the tree is valued and not available for firewood or random destruction. It also probably makes for an aesthetically attractive knothole.
Returning to my thoughts on tree protection, and preventing fatal damage to mature trees in cities, I found this lovely guide to supporting building contractors to make better choices around management of trees on or near construction sites. "Keep a close eye on all operators, be quick to let them know you mean business about unnecessary roughness."
My Service Bush is a stressed plant. Its root system is small and constricted. It could still decline and die from this injury, which is dangerously close to the base of the trunk, and if rot gets into that, the whole plant goes. The injury is too old for clever tricks like bridge grafts and ring-barking, and filling the cavity would be counterproductive. But it's also a strong and wily plant. I have high hopes, that while it may not recover fully, it will achieve closure.
The early trees, the Service Bush and the Winter Cherry, already have swollen buds. The terrible insect damage on the Service Bush has crusted around with woody overgrowth. It's now been two years since the final demise of the beetle grub and the damaged stem is not only still alive, it's thriving. I never took any action to repair the plant, even though the grub left a nasty mess. There was so little to work with; the stem was the thickness of a pool cue, and the bark layer on a Mespilus is so thin, and the heart wood was thinner than a pencil, and full of dead beetle and frass.
The tree response to wounding is not to heal. Instead it compartmentalises the injury by growing healthy, new wood around the injury site, eventually covering it over with new growth. The injury remains, entombed and enrobed in a flood of new, healthy wood. Barrier zones within the transport cells (the famous xylem and phloem) prevent passage of pathogens and decay bacteria from the wounded area to the healthy wood. The wound is steadily brought inside the tree, stabilized, covered over. Cavities may be compartmentalised or flooded with new wood, depending on their size and location. This all takes time.
While I was finding this out, I discovered an internet full of American online guides about how to save damaged trees, and lots of British ones about how to hold people or organisations liable for damage caused by trees. Different perspectives, trees and damage.
There is a technique practised by arboriculturists called scribing, where the damage to the tree is tidied, bark trimmed to a smooth oval, the injury cleaned and made tidy. I didn't do this to my tree. I left the ragged edges to heal on their own. I find myself wondering if this is not something more done by and for the human caring for the tree, to indicate that the tree is valued and not available for firewood or random destruction. It also probably makes for an aesthetically attractive knothole.
Returning to my thoughts on tree protection, and preventing fatal damage to mature trees in cities, I found this lovely guide to supporting building contractors to make better choices around management of trees on or near construction sites. "Keep a close eye on all operators, be quick to let them know you mean business about unnecessary roughness."
My Service Bush is a stressed plant. Its root system is small and constricted. It could still decline and die from this injury, which is dangerously close to the base of the trunk, and if rot gets into that, the whole plant goes. The injury is too old for clever tricks like bridge grafts and ring-barking, and filling the cavity would be counterproductive. But it's also a strong and wily plant. I have high hopes, that while it may not recover fully, it will achieve closure.
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