Tree works are well underway around the park, with much of the northern sector work now complete. At times there may be up to four crews in the park in order to expedite the works which it is hoped will be finished by the end of the month. Some further work may be necessary in the autumn.
A Catalpa tree which had died to the side of the path leading to the Highgate High Street gate has been felled. If you look at the stump you will see that the bark has pulled a little away from the wood. This occurs as a dead tree dries out.
A Silver Birch by the play area has also been felled due to extensive rot and cracking of the trunk. A tall stump is being left so that it may be carved to become a wood sculpture.
Many trees around the park have become overgrown with ivy and in many cases this is compromising the health of the trees. Ivy has now been cut near the base of the trunk of many of the affected trees. This will allow the ivy to die back. After the leaves fall the larger stems and ivy branches will be stripped back in the autumn so that the trees re-gain their shape and can grow again unconstrained.
As tree works overlap with nesting season the teams are taking advice from Camden nature conservation officers and carefully examining trees before starting work, and where they see active nesting sites they are deferring work unless there is an imminent danger to the public presented by the tree itself. Especially in designated ‘nature areas’ and near bird-boxes work is being deferred wherever possible until the autumn. A small tree was felled by the middle pond but further work is being deferred to avoid disturbing nesting ducks and geese.
A large horse chestnut which was in imminent danger of falling due to rot was felled on the Swains Lane border. A further chestnut was lost nearby in the recent past. Options for re-planting are currently being considered including replacement with new chestnuts or a complementary variety.
Waterlow Park is home to three mature Ginkgo trees. These are a fascinating species of generally very resilient tree. (See an article about Ginkgo trees in the park). One of the trees by the path below the Park Centre has unfortunately been discovered to be in an unsound state. Whilst at a glance the tree seems healthy enough on closer inspection lower branches have died, and it is clear that rot is reaching from the roots up to a considerable height hollowing out the tree. Whilst rotting heart-wood leading to a tree developing a hollow structure is not of itself unusual, and hollow trees can readily survive and even thrive for very many years, in the case of the Ginkgo careful assessment suggests that it is likely to become increasingly dangerous and would probably suffer further branch die back from the base if left. Additional indicators of the poor state of the tree include ivy stems that have actually grown into the trunk of the tree so that they are seen disappearing into it. Resistograph tests have also been made. In a resistograph test the trunk is drilled in a number of places whilst monitoring the varying resistance encountered. The resulting readings can plot wood density and give an indication of the health of the tree. Taking into account all the indicators combined with the lean of the trunk and position of the tree a decision to proceed with felling has been made. This has been reviewed on site by The Friends of Waterlow Park, the Head Gardener and Camden Arboricultural Officers.