Its Labor Day weekend and it time for an end-of-summer graft check-up. I've had some great growth on my bark grafts with many scions growing over 5 feet this summer (photo at right). This tree appears to have more leaves at the top of the tree than in the middle and lower portions of the scion. What you are seeing is the result of a normal slow-down of shoot growth that happens towards the later part of the summer. As shoot growth slows, the distance between buds decreases. Likewise, the distance between leaves along the stem becomes shorter as growth slows. More leaves in a shorter stem span gives this tree its top-heavy appearance.
All summer long I've been removing stalked buds from this tree so I wanted to make sure new stalked buds hadn't formed since I checked the tree back in
late July. I looked at the top of the tree (photo at left) and discovered only sessile buds and a well formed terminal bud. This is good news. This tree has stopped growing and can now start hardening-off in preparation for winter's cold.
Not all my trees have stopped growth for the year. The graft pictured at right was still creating new leaves and had formed stalked buds near the top of the tree. My first step was to prune all the stalked buds just like I had been doing all summer. But at this time of year, I made one more cut. I pruned out the tip of the central leader to encourage the tree to start shutting down. A scion that grows vigorously, well into the Fall, is at greater risk for mid-winter cold injury.
I also checked on the condition of each tree's graft union (photo at left). It appears like the tree is healing over nicely. The scion has covered over nearly three quarters of the stock's cut surface. The white paint I applied in early August served to prevent sun-scald to the union and inhibit insects from feed on callus tissue. However, the best thing about the white paint is that now I can look across the field and easily spot which trees I've grafted.
