Our black walnut has reached the end of its life, but its story is far from over. Discover its new life as a wildlife habitat and its remarkable legacy.
Written by head gardener Lucy Hart.
For many years, one particular tree at Fulham Palace has been part of the landscape that I have come to know so well. When I started working here as head gardener in 2011, our black walnut (Juglans nigra) was already showing signs that it wasn’t in the best of health. Over the past 15 years, I have watched it gradually decline: the canopy becoming increasingly sparse, less foliage appearing each year and more dead wood developing throughout the crown.
This year, sadly, it didn’t come back into leaf at all. Our black walnut is now dead.
There are probably several reasons for its decline. I know the tree may have experienced historic soil compaction, including vehicle use on the lawn (which is strictly not permitted since I’ve been in post), which can have a long-term impact on a tree’s root system. And, like all trees, it has been increasingly exposed to periods of drought. Black walnut is considered relatively tolerant of dry conditions, but a tree that is already under stress is much less able to cope when additional pressures come along. Stress can leave trees vulnerable to a whole range of problems, and I suspect this particular specimen had been struggling for some time.
But rather than simply removing the tree altogether, we have decided to turn a negative into a positive.
Standing dead wood
The tree will be retained as a standing deadwood habitat, or monolith, at approximately 8.5 metres high. Far from being an eyesore, deadwood can be an incredibly valuable part of a healthy landscape. The standing trunk and its cavities, cracks and decaying timber will provide habitat for wild bees, solitary bees, wasps, beetles and a huge range of other invertebrates.
When the tree surgeons carry out the work, we will be using techniques such as coronet cuts and snag cuts rather than making everything neat and clean. These more natural-looking cuts leave irregular surfaces and provide opportunities for insects and fungi to colonise the timber and accelerate the natural process of decay. In time, the monolith will become a living ecosystem in its own right.
Making good use of the timber
There is another exciting chapter to the story, too. Walnut is a particularly beautiful and valuable timber, famous for its rich colour and distinctive markings. Rather than allowing all of that timber to go to waste, our fantastic group of green woodworking volunteers will be able to save some of it and turn it into useful and beautiful objects — perhaps cheese boards, bread boards or whatever else their wonderfully creative minds come up with.
I’ll also be saving some pieces and having blocks cut by the tree surgeons for woodturning. I’d particularly like to see some of the timber turned into fruit bowls. So, if there are any woodturners out there who would like to work with a piece of Fulham Palace black walnut, please let me know!
Some of the larger logs and branches may also eventually find a new home in our natural play area, which was created in 2018. The timber there is already beginning to rot down beautifully — it’s remarkable how quickly natural materials can return to the soil. The timing therefore seems perfect to reuse some of these large pieces of walnut to help revamp the play area, funding permitting. The two areas are on opposite sides of the site, so at some point we’ll need to arrange suitable transport for the logs.
Historic connection
But perhaps the most fascinating part of this tree’s story is its connection to another remarkable black walnut.
While researching the species, I discovered an entry on Trees and Shrubs Online about the current champion black walnut tree, growing in Hertfordshire. What makes this especially exciting is that the tree was propagated from a scion taken from a Fulham Palace specimen that could have been grown by Bishop Compton. Its doubtful this current tree is old enough to be the original specimen the scion was take from but its strongly connected, having been growing on the same site, and could be one of its offspring.
This gives our tree an extraordinary legacy.
We know that Bishop Henry Compton, who was Bishop of London from 1675 to 1713, was a pioneering plant collector and cultivated black walnut at Fulham Palace. Compton used his extensive network of missionaries and contacts around the world to have plant material sent back to Britain, including from the North American colonies, where black walnut is native. (We are currently researching who were the indigenous and enslaved people who helped collect the plant material within our research work).
So, although black walnut was already being cultivated in Britain, the Fulham Palace black walnut became significant enough to provide material for propagation elsewhere. And that descendant is still alive and thriving today.
I’ve been in touch with the Tree Register and, more excitingly, with the owners of that Hertfordshire tree. Hopefully, I’ll be able to visit it this autumn. They have kindly offered to save me some of its seeds — the walnuts themselves — so that I can try propagating them, as well as allowing me to collect some hardwood cuttings.
Who knows? Perhaps we can bring a little piece of the original Fulham Palace black walnut back into the collection.
Change in the main lawn’s landscape
So please don’t be shocked when you see our walnut transformed into what may at first look like a tall, straight-stemmed tower of timber. At around 8.5 metres high, this safe monolith will continue to tell the story of the tree while providing an important habitat for wildlife.
And there is one final mystery. We don’t currently know exactly when this particular black walnut was planted. When the tree is dismantled, it will be fascinating to examine some of the enormous branches and, if possible, count the tree rings. Perhaps they will give us another glimpse into the history of this remarkable tree.
The black walnut may no longer be alive, but its story certainly isn’t over.
