March 7, 2015
Wild native trees flourish without human help, but maintaining the size, health and productivity of introduced varietal fruit trees requires periodic pruning– Once begun, the stimulated regeneration of cut tissue requires a commitment to continue the practice, as annual suckers over-grow and create a palette of potential choices, and consequent “unnatural growth.” The annual ritual of selection, with an eye towards a future of adequate light and air exposure, branch placement, & bud count are part of the arcana of an elusive discipline. Even after years of observation, this process remains mysterious, as the ever-growing training ground manifests in un-predictable ways.
Repairing both the mistakes of previously established plantings, and my own early attempts is always challenging, I never want to remove too much wood at once, and consequently the learning curve is on a scale of years, becoming decades!
A major challenge is tree damage, injuries from wildlife, from the pawing and limb breakage of hungry bears, to the root or trunk girdling of subterranean rodents, & the invisible destruction of burrowing insects. In my bio-region, the Flat headed apple borer is a serious threat to young saplings, a tiny pinhole is the first detectable sign, the point of origin for a developing grub that tunnels through the living cambium of the tree. If caught early a wire probe threaded in the hole under the bark can kill individual grubs. This pest is more likely to to take advantage of stressed trees, many early plantings, struggling, under-watered & over-heated specimens succumbed to this tiny insect before I even knew of their existence, as the small diameter saplings were quietly girdled, the vital cambium layer destroyed, the trees vascular flow is choked off, & they soon die. If the tree sustains a less dire injury, the race is on- will new tissue outpace the seed of decay?
Many older trees show the healed scarring of early injury. Woodpecker holes ring mature trunks with little effect. Steady growth can often outpace the damage sustained.
Prune trees are vigorous and hardy European plums that produces a firm, fleshy fruit perfect for drying. This French varietal is less than ten years old and sustained early borer damage that threatened its survival. Every year I survey the extent of the encroaching decay caused by the initial injury. Removing decay, chiseling protuberances down to sound heartwood, gently abrading the leading edge of the wounded areas to stimulate scarring, and protecting the damaged area from sun, water and dehydration with a coat of acrylic latex paint.
As its ever increasing girth and advancing scar tissues attempt to encapsulate and isolate damaged tissue, the healthy side of the trunk is compensating for the vascular needs of the tree, and one day can regrow enough to protect the vulnerable interior,
Extending the life of this otherwise healthy and productive tree
