Archive for the ‘Tree Team and Propagation’ Category

Plant hunting . . . an exciting opportunity to make a difference!

Friday, October 7th, 2016

New specimens are the lifeblood of any botanical collection. They are needed to provide an all-important uneven age structure, which should ultimately ensure there will be trees for future generations to enjoy.

Together with an expert from Royal Botanic Gardens Kew, we are about to set off on a three-week trip to Italy this autumn to search for internationally important tree species.  We will be travelling light and covering as much ground as possible to make the most of this exciting opportunity.  We’ll start collecting in the far southwest, before heading to the northeast.

Dendrologist Dan Crowley, Propagator Penny Jones and I will explore hundreds of miles of Italian countryside to seek out a target list of species that we have carefully selected for a variety of reasons.  We will be accompanied throughout our trip by several Italian botanists and researchers, who have kindly helped us with the planning and logistics.

Left to right: Dan, Penny and Mark.

Left to right: Dan, Penny and Mark.

Some of the trees and shrubs identified as targets will be familiar, but it will be useful to test a more southerly provenance of these species in view of our predicted changing climate.  When I asked Dan what he was hoping for, he immediately stated his main aim is to collect seed from Lobel’s maple (Acer lobelii), as this is rare in the wild and in cultivation.  Penny wishes to see trees growing in their native range and habitat, which will importantly help us to position new plantings correctly within the Westonbirt landscape.

The species that are grand in size will be sought to maintain and develop the historic landscape at Westonbirt, but there is potential that some of these species could also have a big impact on the forestry industry in years to come.  In partnership with Forest Research, we have been gathering information on a few key species which have the potential to become timber trees, hopefully with less risk of pest and disease.

Recent work by our Forest Research colleagues has shown that European silver fir (Abies alba) can be a productive species when grown in Britain, and could be more widely used to diversify our UK forests.  The work showed that seed collected in Calabria, Italy performed well and we now need to establish better contacts in this area to collect new seed.  We also want to learn more about how altitude, soils and other factors affect the growth of this tree.

We will endeavour to provide a few updates along the way, and as always, we look forward to seeing how well these new trees will grow at Westonbirt and elsewhere.

Tree of the month: October 2016

Tuesday, September 27th, 2016
What is tree of the month?

Nyssa sylvatica


Why is it tree of the month?

One of the very best trees for autumn colour, Nyssa sylvatica never disappoints. It is somewhat overlooked at other points during the year but come October, it stands out even among the riot of colour with leaves that turn strong shades of red, orange and yellow. It really is worth trying to catch our trees at their best.

Native to eastern North America, it grows in the company of many other of our favourites for autumn colour including cherry birch, Betula lenta, bitternut, Carya cordiformis and red maple, Acer rubrum.

Where can I find it?

Examples can be found dotted around both the Old Arboretum and Silk Wood, including on Pool Avenue, Holford Ride and Broad Drive.

A day in the life of a student arborist

Tuesday, September 20th, 2016

Once again our student arborist placement is well under way, and this year we’ve been thrilled to receive the generous support from two funders, the Finnis Scott Foundation and the Ernest Cook Trust, which has covered all the costs for one of our placements.

Joe is with us following his studies at Myerscough College, and having been with us for 2 months, he’s definitely getting stuck into the role. We asked him a few questions about his experience so far.


How’s the placement going so far?

It’s going well – there’s been a really good mix of practical activities and desk-based work. It’s been great as I’ve been able to really tailor the role in terms of getting bits of experience I need. For example, I wanted to get to grips with job-coding, which involves examining trees and determining their health and how much upkeep they need going forward. Mark [Westonbirt’s curator] has been really accommodating in making sure I’ve been able to take on tasks to ensure I gain skills in all areas of tree management. It’s also been good to be around people with so much knowledge. Everyone’s prepared to take the time out and pass on the benefits of their experience.

What’s been the best bit? What have you particularly enjoyed?

Definitely tractor driving, which I hadn’t done before I started at Westonbirt.

Is there one key thing you think you might take from this experience?

A highlight will definitely be being able to look back and see that I’ve been able to influence the landscape.

And what are your future plans?

I’m hoping to go into land management, working for a tree team as an arborist or I might even go freelance as a consultant.


Mark, who manages the placement and is Westonbirt Arboretum’s curator, believes fervently that this placement is of huge value both to the arboretum and the students.

The placement is well established and has been running successfully for many years now, and it really benefits both parties. 

The students obviously gain valuable work based experience and not only learn new skills but put existing experience into practice. They always enjoy the chance to use the academic knowledge gained at college or university in a ‘live’ situation, and take a lot back into the final year of study. They always find the chance to work alongside experienced practitioners very beneficial, as our arborists can pass on helpful insight and practical tips on a daily basis. 

We in turn enjoy fresh faces in the team each year, bringing enthusiasm, the latest thinking and an exchange of ideas. It keeps us on our toes, as the students are constantly questioning our methods and reasoning. This regular scrutiny helps us to make sure we are on the right track with our plans and policies in particular.

The opportunities to gain essential experience can be limited, especially for mid-year students, and so we feel it is very important to keep this offer alive. After a year with us undertaking a wide variety of different tasks, students often have a much better idea as to which particular area they would like to specialise in the future too.”

Thanks again to the Finnis Scott Foundation and Ernest Cook Trust for their generous funding. Our student arborist placements run every year and need funding to cover a salary for the student, qualifications & certification, tools & equipment, learning visits to other arboreta, and clothing & personal protection equipment.

If you would like to support the tree team by making a donation, please contact

A sad story to share…

Tuesday, September 6th, 2016

Over 450,000 visits are welcomed at Westonbirt each year and the vast majority of people enjoy a wonderful time in a picturesque setting.  Thankfully, problems such as anti-social behaviour or vandalism are extremely rare indeed.  And even more unusual is intentional damage to any of the trees and shrubs within our collection.

However, this was regrettably not the case recently. Our tree team found what strongly appears to be deliberate stripping of bark from the stem of an old Rhododendron, within a handsome group of specimens on Circular Drive.  Sadly the damage didn’t stop there as not only was the bark been stripped from ground level to six feet up, but people’s names and other messages have been carved into the bare stem of this plant.

We are in the middle of a big project across the Old Arboretum of identifying Rhododendrons and this was one we were interested in as it produces an array of attractive white flowers tinged with pink every year.  Unfortunately this Rhododendron group is also very special to someone, as it is commemorated.

Bark is to a woody plant what skin is to us humans; it performs the essential task of protecting the tissue within. The loss of this amount of bark has resulted in the need to fell the particular stem.

As Curator, it’s hard to understand the motivations for this and I’m sure it’s something that every botanical collection faces as their popularity and appeal grows far and wide.

Whilst I felt it was worth highlighting this as one of challenges we face here at Westonbirt, these incidents are particularly rare and the Rhododendron will, we hope, continue to live happily one stem down.

Mark Ballard


Carrying out some TLC

Tuesday, September 6th, 2016

The Tree Team are currently working hard between Broad Drive and semi-natural woodland beyond the western side.

This is an area that has needed attention for quite some time as there is a line of young woodland trees, mainly ash and sycamore, that are adversely affecting the growth of our specimen trees.

This section is designated as ‘arboretum’ instead of ‘woodland’ within our long-standing Forest Design Plan, so we have decided to act now, in order to prevent further suppression of the specimen plants.  The problem of suppression is exasperated on this particular side of Broad Drive by some over-mature Leyland cypress, that will at some point in the future be in danger of blowing over if left standing.  They have become very big and tall, and unfortunately block out a great deal of important light.

IMG_1671 IMG_1677

So you may hear the sound of chainsaws, as the appearance of this part of Silk Wood changes for the better and this landscape restoration is complete.  I can assure you that the views from Broad Drive will be much improved, and of course as always with any tree removal, we will be looking to plant a few more attractive specimens when the ground has had chance to settle down.

Mark Ballard

Tree of the Month: September 2016

Wednesday, August 24th, 2016
...with Dendrologist Dan Crowley.

…with Dendrologist Dan Crowley.

What is tree of the month?

Magnolia grandiflora


Why is it tree of the month?

The evergreen magnolia from the south east United States is fairly often seen growing against walls in this part of the world but in slightly warmer climes it can make an impressive standalone tree.

There are many forms in cultivation with some noted for foliage  but the real treat is the flowers. Appearing in late summer through early autumn, these can be over 20cm across and are creamy white and very nicely scented. Its tendency to flower somewhat intermittently means there is plenty of opportunity to have a good look.

Where can I find it?

Our best specimen grows against a wall of Keepers Cottage, adjacent to Propagation.



Tree of the Month: August 2016

Thursday, July 28th, 2016
...with Dendrologist Dan Crowley.

…with Dendrologist Dan Crowley.

What is tree of the month?
Sorbus ‘John Mitchell’

Why is it tree of the month?
Notable for its huge round leaves, this whitebeam, Sorbus ‘John Mitchell’ is a not uncommon sight in cultivation and has its origins here at Westonbirt. It was long considered to be a selection of Sorbus thibetica but is in fact something quite different. One of its parents is likely to be a round-leaved form of our native Sorbus aria and the other is as yet unknown, though is likely of Asian origin. The hybrid first arose here (precise date unknown!) and was named for the first curator of Westonbirt, William John Mitchell.

Where can I find it?
We currently have two trees in the collection (we are keen to grow more!). Our largest stands close to Mitchell Drive (G25 on the map) and a smaller but equally beautiful tree is located close to another of our famous trees, the Holford pines (Pinus x holfordiana), near Holford Ride (E24).

Dan Crowley, Dendrologist

Tree of the month: July 2016

Monday, July 4th, 2016

What is tree of the month?
Stewartia monadelpha

Dan Crowley
Why is it tree of the month?
Stewartia is a member of the tea family, Theaceae, as suggested by the solitary white flowers that appear in summer. S. monadelpha has the smallest flowers in the genus and these are borne in some profusion on branches throughout the crown. The flowers have conspicuous bracteoles which are a useful aid to identification and the tree is also notable for its reddish bark which peels.

Stewartia monadelpha
The genus was named after John Stuart, Earl of Bute (1713-92), though Linnaeus was misled into spelling the generic name ‘Stewartia’ rather than ’Stuartia’ which led to some confusion around which should be used. Though there was widespread use of ‘Stuartia’ in the 19th century, the accepted spelling is Stewartia, as found in modern botanical texts.

Stewartia monadelpha
Where can I find it?
Currently we have just two trees here at Westonbirt. These are both on Circular Drive in the Old Arboretum and enjoying the acidic conditions they are afforded in this area.

Dan Crowley, Dendrologist

Tree of the month: June 2016

Tuesday, May 31st, 2016

Dan Crowley, Westonbirt's dendrologist
What is tree of the month?
Aesculus indica (Indian horse chestnut)

Indian chestnut - whole tree
Why is it tree of the month?
The Indian horse chestnut is notable for both its bronze new foliage (see the whole tree photo!) and flowers in panicles that provide an arboreal highlight as we move in to the summer months. The leaves turn a glossy green and the showy flowers usually appear in June to July and look as though they won’t too far away this year! In maturity the bark peels in long strips.

Indian horse chestnut - leaves and flower headsIndian horse chestnut - bark
The species is native of the north west Himalaya and was introduced in 1851. It is seen far less frequently in the UK than its European relative, Aesculus hippocastanum, and its later flowering time than this species is an added attraction.

Where can I find it?
Our largest example can be found on Loop Walk in the Old Arboretum and an equally interesting example of multi-stemmed habit is found close to the relatively new path which links Mitchell Drive and Main Drive in the Old Arboretum.

Dan Crowley, Dendrologist

Tree of the month: May 2016

Friday, April 29th, 2016

What is tree of the month?
Abies delavayi

Abies delavayi - female cone

Why is it tree of the month?
Delavay’s fir, named for the French missionary P.J.M. Delavay who collected plants in China in the late 1800s, is a species found at high elevations in southwest China and neighbouring regions. One of a number of Abies species that have blue cones, they are particularly noticeable just now. Abies species tend to produce cones towards the top of the tree and not all do so when young, but one of our plants, planted in 2002 has been doing so for the last few years. What is more, many of the are on low branches making them ideal for a closer look, or the odd photograph!

Dendrologist Dan Crowley admiring Abies delavayi

Where can I find it?
This particular specimen (17.0253) is found between Mitchell Drive and Main Drive, close to the boundary with the Downs. Another, from the same seed source, grows along Broad Drive, though doesn’t form cones so reliably.

Abies delavayi - whole tree

Dan Crowley, Dendrologist