3 months ago a large Sycamore tree at High Kelling Hospital lost a limb during one blustery afternoon, no damage done but a worried homeowner whose workshop was underneath the tree. We were contacted by SERCO – Anglian Support Partnership (National Health Services grounds maintenance company) to identify and compile the data, survey the site and submit a management plan to reduce the risk of a larger failure. The survey found that the homeowner had contracted in another arboricultural contractor to complete a crown thin and reduce some of the over hanging limbs. Our findings from our arboriculturalist found that:
1) Some reduction points were taken to internodal points resulting in sporadic and dense reactive regrowth causing an increase in crown sail at the branch ends.
2) Over pruning by removal of 35-40 of the total green matter (leaf area) along these branches, confined to a 15ft area off the main stem.
3) Point 1 & 2 have been key in the failure of the limb onto the property through
a) Increased volume and reduced airflow on the tips of the crown.
b) Increased lever arm, which has had an increase in weight every year after the initial and incorrect pruning techniques.
So the findings had found that the tree was at risk of multiple failures of this kind. So the next step was to draw up a management plan to reduce the risk of limb failure for the next 5 years. We choose a sympathetic lateral crown reduction with no thinning of the crown to allow the construction of a smaller crown but denser in the future to keep the percentage of leaf area roughly the same as before the pruning happened which caused the limb to fail.
Jump forward to today.
We arrived at the site in Holt for 8am to meet with the homeowner and with the help of my trusty laser pointer explained exactly where we were going to cut and reasons why (backed up with the report of course). Carrying out the remedial works was tricky enough, every single piece had to controlled, lowered and redirected to clear the building below. Normally this type of reduction works will take anywhere between 2-3 hours, with the added structure below this task took around 6 hours to complete but the task came in on time with our client pleased with the works.