March 30th, 2015

Acer pycnanthum in autumn

What is tree of the month?
Acer pycnanthum – the Japanese red maple

Why is it tree of the month?
A rarity in the wild and less familiar in cultivation than it’s American counterpart Acer rubrum, it is going to flower for the first time here at Westonbirt!!

Where can I see it?
Close to Loop Walk on the north end of Holford Ride.

Dan Crowley, Dendrologist

Testing! Testing!

March 30th, 2015

Come to Westonbirt on the 8th and 9th of April and you can help us to user test our brand new app!

Westonbirt App visual

We are especially looking for people aged 12-21 who have a smart device (iOS or Android) to take part. The app allows you to create a new arboretum adventure with challenges along the way.

Participants can use the app on one of two specially created trails (one in Silk Wood and one in the Old Arboretum, which is a dog-free zone) and then tell us what they really think in exchange for a hot drink and a crème egg!

Not in the age bracket? Don’t worry; you can still have a go at the app! Look out for the app testing banner and a member of staff as you enter through the Welcome Building, for more information. We’ll help you download the app and get started on your adventure!

We look forward to seeing you there for some tree challenges!

Susanna Byers, Interpretation Support Officer

Stuck between rot and a hard place…

March 16th, 2015

Deciding when to remove old trees is one of the hardest decisions we have to take here at Westonbirt. All of the arboretum’s trees are regularly inspected for safety reasons and we try to strike the balance between allowing old and valuable trees to remain and visitors’ safety.

As trees reach the end of their lives they tend to go into decline (known as senescence) and as managers we try to care for specimens through this process, for example by gradual crown reduction. However, we can only delay, rather than prevent, the inevitable. Sooner or later we have to say goodbye.

The time has sadly come to fell a magnificent giant redwood (Sequoiadendron giganteum) that has graced Main Drive since the Holford family started their arboretum in the mid-nineteenth century, as its health has been in decline for many years. We have taken the difficult decision to remove it following lots of close monitoring and some recent investigations. Although the decline of this specimen is fairly obvious, it can be tricky to get a clear picture as to what is actually happening inside a tree’s trunk.

The external signs of decay

The external signs of decay

To help us in this instance we recently arranged a specialist test on this tree with the Treetronic system, which uses electric current/voltage to investigate the internal properties of the tree. The result of the measurement is a two-dimensional map of the electrical impedance (EI) of the tree. Importantly, each tree species has a typical impedance (water/moisture) distribution, and to properly analyse the EI results, the operator should have a good working knowledge of how the subject tree species grows and how the water/moisture distribution may vary in different seasons.

As suspected, our results indicated a central column of dysfunction/decay, which corroborates the external characteristics. The resulting diagram for this tree revealed a high degree of decay (red areas), which matches the outer visual evidence. Based on past experience, we can assume that the decay also extends into the root plate, which would adversely affect the tree’s stability.

Graphic showing internal decay in red

Graphic showing internal decay in red

On a brighter note, we do have over 50 other giant redwood specimens throughout the arboretum, and we also hope to collect more wild seed later this year from western USA.

Finally, if a reminder were ever needed that our trees do not live forever and that we do need to manage older specimens in particular, then just a short distance away on Loop Walk you can still see the uprooted remains of a large Nootka cypress (Xanthocyparis nootkatensis).

The uprooted remains of a large Nootka cypress

The uprooted remains of a large Nootka cypress

This tree was being monitored closely due to decay in the base, but unfortunately fell during high winds over the Christmas period before we had chance to remove it.

Mark Ballard, Curator

New life and old traditions

March 9th, 2015

The role of the Community Inclusion team is to enable a greater number of people from under-represented groups to experience the arboretum and to connect with trees. Funded by the Heritage Lottery Fund, Community Youth Officer, Karen Price is working with young people so that they can discover, explore and enjoy the arboretum, either as part of an organised group or as individual visitors.

A group of young people around a camp fire

Its been a busy time in the coppice coups at Westonbirt this winter with the Community Coppice Programme. Almost 50 teenagers have now swapped their pristine trainers for green wellie boots and endured rain, and even snow, to bring new life into one of the derelict coppice coups off Willesley Drive.

The Battle of the Bramble is nearing an end with just a few rogue tendrils holding out against the onslaught of loppers that has rained down on them. Hazel, holly, field maple and ash, all of which have been quietly going about their own business of growing for the last 80 years, have been felled and processed into bean poles and faggots, pea sticks and hedge stakes.

Coppicing in Silk Wood

But what may at first glance look like a scene of destruction, is already springing back into life. It seems strange to cut down a tree to help it grow but that is really what coppicing is all about. The arrival of spring will stimulate a vigorous regrowth of multiple stems from the remaining stump, which will quickly flourish into trees again.

Bluebells, orchids and Arum lillies are beginning to poke their heads above ground, and the increase in sunlight now reaching the woodland floor will soon awaken wood anemone, primrose and hopefully violets. More wild flowers means more butterflies and the birds that feed on them and their larvae. And before long, the biodiversity of the once derelict coppice is thriving once more.

And what about the wellie wearing teenagers? They are helping to keep alive centuries-old traditional skills; learning about managing the woods, charcoal burning, carving spoons and making faggots.

Time for contemplation

But they are also taking away a lot more. They have learnt perseverance when lighting a fire in the rain. To take risks to try something new and to manage risk when felling a tree. To work as a team by looking out for each other’s safety and wellbeing and to break down a task between them to make it more manageable. They have learnt to trust themselves with sharp tools and that others have trust in them. And for me, most importantly, they have learnt to explore and discover and be amazed by the world around them.

Karen Price, Community Youth Officer

Tree of the month: March 2015

February 27th, 2015

Illicium simonsii

What is tree of the month?
Illicium simonsii

Why is it tree of the month?
It is a lovely pyramidal shrub with small, pale yellow, fragrant flowers that are worth seeking out for both their look and scent. It usually flowers towards the end of the month, so keep your eyes peeled!

Where can I see it?
It can be found in both the Old Arboretum (close to Main Drive and Savill Glade (tree number 25.0799)) and in Silk Wood (Sand Earth (31.1424)).

Dan Crowley, Dendrologist, Westonbirt, The National Arboretum

>> Visit the Westonbirt Map to search for trees by name or tree number

The Wolfson Tree Management Centre: An Update

February 26th, 2015

The new yard is now complete!

The new yard
This is a photo taken from the new viewing area location where visitors will be able to view the Tree Team at work.

The new yard

This photo shows the completed vehicle wash-down ready for the jet wash and scrubbing brushes! The temporary fencing around the new yard will soon be replaced with a solid timber fence with a viewing section into the yard.

We are about to appoint a contractor including timber framers who will build the large ‘machinery store’ building using the timber from Westonbirt, which was hewn and milled on site. Work will begin in April. See the artists’ impression below showing a 3D model of the timber frame.

Superstructure of Machinery Store_3D Image

Sophie Nash, Project Manager

Offers just for Friends

February 20th, 2015

Our spring 2015 magazine is out now and contains some great offers for Friends of Westonbirt Arboretum. You’ll need to show a valid membership card to claim the discounts and offers. Enjoy!

  • Cattle Country 20% off for all Friends of Westonbirt Arboretum members – bring magazine voucher with you (page 28)
  • King’s Arms FREE bottle of house wine with a 3-course meal for two – quote ‘FOWA’ when you book and bring your membership card (page 33)
  • Spring Special at Mayfield House Hotel. Buy 1 Get 1 Free on main courses (page 54)
  • Landcare – trees shrubs and wildflowers – 10% off to Friends until 31 May (page 57)

Make sure you look at the adverts in the magazine itself for any additional terms and conditions. Click on the cover image to read online!

Spring 2015 magazine cover

Lousia Lockwood, Editor

Tree of the month: February 2015

February 1st, 2015

Picea farreri
What is this month’s tree of the month?
Picea farreri
Farrer’s spruce

Why is it tree of the month?
Graceful form, glaucous (blue-ish!) foliage.

Where can I see it?
Sand Earth in Silk Wood, set slightly back from Willesley Drive.

Dan Crowley, Dendrologist, Westonbirt, The National Arboretum

The Wolfson Tree Management Centre: An Update

January 30th, 2015

Work is currently underway on what will become the new Wolfson Tree Management Centre. The new facility will provide all that Westonbirt’s expert tree team needs to manage the tree collection.

The foundations and floor slab are now complete for the new machinery store. The contractors have now started work on the drainage and completing the new yard.


This is a photo taken from the edge of the new yard marked out with a timber edge. Drainage channels form a boundary around the new building to protect it from heavy rainfall and to ensure any rainwater runs along the channels and pipes to a soakaway.


This is a photo of the first section of the new yard which has been finished. This area will become the tree team’s new vehicle wash down and fuel fill up point, their own a miniature fuelling station! The waste water and any potential spills of oil or diesel will drain along the new channel, where it is then filtered by a very large oil interceptor tank, see photo below. This tank holds any leaked oil and fuel which we can then remove safely.


The new yard and building floor slab have been created with a very high level of care and attention to detail although the brush finish across the site has been created by using just a brush and some rope!


Sophie Nash, Project Manager

A Wonderful Winter Walk… with one exception!

January 27th, 2015

Today I ventured over to Silk Wood to see how some of the Tree Team were getting on with essential tree safety work, which reassuringly was being carried out to a high standard as always.

I was also pleased to see that other team members together with volunteers had resurfaced parts of our rustic woodchip path network, using safely processed material from our very own on-site woodchip pasteurisation unit.

Brian Williamson credit to Charles Budd
I bumped into two of our independent coppice workers nearby, busy tending to the freshly cut hazel stools in one of their coups.

Large parts of Silk Wood have been managed for hazel coppice with oak standards over hundreds of years, and it can be a rare pleasure these days to see people managing such woodland in the traditional way.

If you look closely, you may even see the coppicers putting the cut hazel to a variety of different uses depending on the thickness of the stems.

I believe that we are very lucky to have wooded areas to enjoy at Westonbirt, as well as the contrasting open space of the downs and landscaped parts of the arboretum.

It was beautiful out in Silk Wood but I was very sad to find lots of discarded plastic dog poo bags and surprisingly even some abandoned bags full of dog waste and tied.

It’s in everyone’s best interests to keep the whole arboretum tidy, so that the magic of the place can be enjoyed by all.

But it is also a working environment and looked after by a small and dedicated team, and it is not very pleasant for them to stumble across dog waste during a working day.

I would kindly ask visitors to help us to look after the arboretum, by just popping poo bags in the bins provided.

Mark Ballard, Curator