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28 Dec 2023

The PLANTS project: looking back, planning ahead

Written by Dr Colin McDowall, PLANTS Project Manager
A composite image made up of five photos showing various aspects of gardening. In the top left is a shrub absolutely covered in pink flowers. In the top right is a rhododendron with deep red flowers. In the bottom left are three people dressed in navy jackets and all wearing midge nets. In the bottom right are a row of nine people standing in a garden. At the centre is an image of an interpretation board in a garden, explaining the PLANTS project.
Some image highlights from 2023
With 2023 coming to an end, the PLANTS project manager takes a moment to look back and take stock of a year with lots to celebrate.

2023 is coming to an end and it genuinely feels as if the year has flown by. It certainly was an incredibly busy one for everyone at the PLANTS project. The new year is always a good time for self-reflection, and so this blog takes a look back at the year that has gone.

I sat down to write this on 1 December. Outside, the garden was covered in snow and the weather was a chilling -6C – a strong case for battening down the hatches and venturing outside as little as possible. However, for the PLANTS project team, with our garden audit year now at an end, many of us are starting to plan for the future.

Where we’ve been in 2023

I thought it would be nice to begin by highlighting some of the things we have achieved in 2023.

We started the year by organising spring/summer revisits to our 2022 gardens, in order to audit seasonal plants in bloom. It was lovely to be back at Broughton House, Crathes, Culzean, Drum, Greenbank, Holmwood, Haddo and Threave, seeing the gardens from a different perspective. By August we had finished all these revisits and processed all of the associated data – ready for it to be handed over to garden staff. This was a major achievement for the project.

Since 2022, the teams have updated our IrisBG catalogue with the identity of 22,415 living accessions in these gardens, 9,962 of which have been added during the project. As I discussed in my last blog, some of the findings from these gardens are extraordinary. For the first time in many years, eight Trust gardens have a fuller understanding of what is in their plant collection. To complement this access to the database, we’ve developed training workshops, ‘how-to’ guides targeted to the needs of the gardeners, and accession books. Our training workshops alone have reached more than 60 people so far. As we pass responsibility for the records onto individual gardens, I feel confident that we can trust the data in such safe hands.

While it was satisfying to be able to finish most of our 2022 gardens, there was certainly no chance for us to rest on our laurels (no pun intended!). From July onwards, we began visiting our brand new cohort of gardens for 2023. Despite it being – according to the Met Office – the fifth warmest summer on record as well as wetter than average, our three project teams were able to complete initial audits at 14 new (to the project!) gardens across Scotland.


Our teams explored a diverse portfolio, from the 16th-century Falkland Palace to the 20th-century Hill House. Across these gardens, the team produced a total of 32,937 audit records – up from the 20,000+ produced in the summer of 2022. However, the project is more than statistics; the personal learning and development of the teams has been heartwarming, with people’s interests in specific species such as Sorbus or herbaceous plant collections becoming more evident in the last year.

The lore of the garden: stories, cultivars and historical plants

Many of the plants we have recorded have historical connections with men and women who were passionate about plant collecting, cultivation and display. From the giant Eucalyptus and Nothofagus at Crarae to the collection of heritage apples at Priorwood, we have come across gardens shaped by collectors. The gardeners at each property were keen to share stories or ‘lore’ from their collection. At Crarae Garden I was entranced by a large grove of Eucalyptus that looked almost prehistoric – it was said to be one of 20 species planted by Sir George Campbell from Tasmania.

By contrast in size, Branklyn is one of the Trust’s smallest garden but holds a wide range of alpines, especially Sino-Himalayan plants from collecting expeditions sponsored by John and Dorothy Renton in the early 1920s, alongside National Collections of Meconopsis and Rhododendron. Data work is ongoing but over 100 original Renton plants have been found in the garden. One that particularly attracted my attention was the Kenilworth ivy (Cymbalaria pilosa), a ground-hugging alpine that grows along the border of the house. It was found to date back to 1930. For nearly 100 years, it has unobtrusively grown away, passed by millions of visitors to the garden.

The same can be said for the oldest rose plant we’ve come across so far: Rosa ‘Scharlachglut’ (‘Scarlet Fire’). Planted in 1921 in the Delphinium Border at Falkland Palace, it is a handsome shrub rose with large scarlet-crimson single flowers. Similarly, we came across a holly (Ilex) dating back to the 1850s at Leith Hall and what is believed to be one of the oldest holly trees in Scotland at Castle Fraser.

Interesting Rhododendron and fern specimens were found at Arduaine. In the late 19th century, James Arthur Campbell, newly returned to Argyll from his tea estates in Sri Lanka, began building the garden. Campbell must have seen Rhododendron arboreum ssp. zeylanicum growing wild on the central plateau of Sri Lanka. The species at Arduaine was one of the first to be planted in the UK raised from wild collected seed: six thriving specimens of this tender species, now over 100 years old, were a highlight of the original collection. Another historic specimen is Rhododendron protistum, the first plant of the species to flower in the western hemisphere in 1936. Equally awe-inspiring is the wonderful specimen of the native scaly male fern (Dryopteris affinis ssp. borreri) which is some 3ft across and 2.5ft high. Legend reckons this plant could be 1,000 years old, but we have no way of proving this.

Finally, this year at Crarae Garden I fell in love with the unusual form of Fagus sylvatica ‘Crarae’. It’s a rare type of beech tree, based on its unique leaf morphology; three of the five known to be in existence are found in this enchanting woodland garden. Also this year we came across Meconopis ‘Crarae’ and ‘Branklyn’ cultivars, as well the Prunus serrula ‘Branklyn’ (recipient of an RHS Award of Garden Merit) propagated from a tree in Branklyn Garden in Perth.

The team evolves

We were absolutely delighted to have our brand new East team join us this year. Alistair and Charlotte have already completed initial audits of 6 of the 11 regional garden properties. The team spent the spring learning from the West team at the Greenbank audit before beginning their first audit at Inveresk Lodge Garden.

We have also been so grateful for the input of our three new volunteers. Roy spent three months inputting historical property accession records, and Diane and Lesley are currently cleaning the Greenbank Garden dataset. Their legacy cannot be overstated. We so appreciate their willingness to give up their time every week and use their skills to improve our plants database.

Finally, we were sad to say goodbye to our administrator, Rob, who left us in November for a new role. He was a huge support to the rest of the team, and will be much missed. We look forward to welcoming his successor in January and to everything that she will bring to the project.

Collaborating, learning and adapting

In 2023 we’ve been revising our technique for recording plants that are outside the core collection area of a garden, such as shelterbelts. Instead of giving an accession record to each individual tree (which could amount to thousands of records for the same species), we create a single record for each species of tree within an area. These ‘presence’ records, as we call them, allows the Trust to maintain and care for our woodland collections. Before our audit, the Trust would have had to contact each individual property to find out about the presence (or otherwise) of various species. With the rise of plant diseases like the recently announced Curreya pithyophila fungus (which attacks Scots pine), it is vital that we can understand our collection on a national scale.

Another development this year was working better and smarter with GPS. In March, gardeners at Threave shared an app with us that they had been using to report issues with paths. Since then, we have recorded the GPS co-ordinates of planting beds and significant plants. While auditing Arduaine and Crarae, we also benefited from preparation work done by the garden staff, helping to define boundaries between adjacent beds. The simple idea of using bamboo canes and loop-able tree labels made things very clear and saved us so much time.

Strength in numbers: collaboration and cataloguing

This year we have worked closer than ever with garden staff and the Gardens and Designed Landscape Managers (GDLMs) for each region. Thanks must go to Simon Jones and Tim Keyworth, GDLMs for the West, for supporting their region’s head gardeners to commit themselves and their teams to audit alongside us. Mention must also go to Chris Wardle, GDLM for the North East, who helped with audits at Castle Fraser and House of Dun. We really appreciated their insight and enthusiasm to get the job done.

The Edinburgh & East audits started in 2023 and the team benefited greatly from research and audits previously undertaken by GDLM Colin Wren – information compiled over many years through personal identification, comparing examples from across the UK, and examining invoices. Together with garden teams, the GDLMs demonstrated a real desire to understand and own the data for their garden(s).

The smoothest audits were the ones where the garden team were directly involved with decisions being made regarding plant identification and collection recording. If you had asked me at the start of 2023 which gardens I was most nervous about, I would have immediately named Arduaine, Crarae, Inverewe and Branklyn! All are large sites with complex terrain (except Branklyn), true plantsman’s gardens with collections of national importance and that are estimated to be in the high thousands of records. The gardeners freely gave their time to do prep work, identify plants, find tag numbers and venture into undergrowth in the pursuit of answers, all of which greatly sped up our progress.


Since the PLANTS project launched in June 2022, more than 62,000 record descriptions have been added and/or edited in our plants catalogue, IrisBG. Looking back over this last year, I have been proud of the resilience and adaptability of the PLANTS project team. In many ways, 2023 threw more personal challenges to us than 2022. The fact that everyone remained cheery – even when drenched by rain, attacked by midges, or baking in the summer heat – demonstrates their special spirit. 2024 will be the final full year of the project and I look forward to what new adventures and lessons will unfold.

Plant Listing at the National Trust for Scotland (PLANTS) is the biggest horticultural audit project undertaken by the Trust and aims to celebrate, protect and better understand the flora and vegetation across our gardens and designed landscapes.

Read more about the PLANTS project

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