The Encroachment of an Old Tree

Collapsed Lilac

A bit of a problem with a tree: October 2021

I had noticed the encroachment of the lilac over a dormant and barely used child's trampoline but I assumed this was simply all down to the tree's growth. One autumn day revealed a more significant problem, however, as a sizeable section of the tree collapsed and was only being supported by the trampoline frame and an old pallet. There was clearly some work to do here and my initial task was to extricate the trampoline.

The trampoline hadn't been used for a long time - children's needs change with their growing maturity - but its disuse was perhaps in part due to the branches that had started leaning over it and also because of some undergrowth of brambles. I would periodically remove these and note, with admiration, the rapid growth of a bramble. They could easily string out a length onto and across the trampoline's 8-foot diameter. In recent years the trampoline's primary users have been the local cats, finding its heat-trapping black mat a comfortable place to repose.

The collapse of the lilac's limb provided the motivation to permanently rid the garden of the trampoline but its removal wasn't entirely simple, especially with an extensive part of the weight of the limb upon it. Rusty bolts, the usual quota of weed growth and legs bedded firmly and gripped by grass roots added to the general challenge. It eventually emerged in its constituent parts from beneath the tree and has now found its way to a new home courtesy of Freegle.

The pallet which was partly holding some of the collapsed limb's weight was part of a construction the children had made many years ago to form a bit of a den within the tree. There were other bits of old den still being clutched by the lilac's branches. These mostly just comprised logs resting in the tree in horizontal arrangements but there were a few elements of the old den that were tied in place with orange baling twine. When I finally removed all of the den debris, including the pallet, the limb of the tree fully laid itself down in the newly created space of the trampoline void.

Lilac's tend to grow in multiple trunks from the base of the tree so perhaps 'limb' is the wrong term to have used to describe the section that collapsed. It's really a sub-trunk. Examining the base of it, there was clearly evidence of weak, partly rotten wood. I'm not sure if the tree has a disease but I suspect this is just how lilacs age; the sub-trunk had just reached a point where it could no longer support its own weight. Lilacs produce many suckers in the course of a growing season and it seems like this collapsed trunk will just produce new suckers itself and thus slowly spread itself outwards. I think yews behave in a similar way, eventually creating a natural ring of trees around an original tree which eventually decays completely to just leave the ring of newer trees.

For my lilac sub-trunk, I wanted to let it behave as naturally as possible but its outer branches extended rather too far. They spanned the whole of the space previously occupied by the trampoline and extended up onto a border area on the next level. I decided we needed to share the newly reclaimed trampoline space. The tree could have half of it to itself to grow new suckers or gradually decay the collapsed trunk. A bit of trimming was therefore required.

It will certainly be interesting to see how the tree behaves during the next and subsequent growing seasons. Even if this section of the tree dies and decays completely, it will provide shelter and nutrients in doing so and is therefore a valuable wildlife resource.