See all stories
25 Aug 2021

Planting for the planet

Written by Aileen Scoular
A view of the walled garden at Crathes Castle, looking towards the castle diagonally across a square flower bed. Shaped yew hedges surround a square pool at the centre of the bed, with colourful flower beds around the border. Gravel paths run along the outside.
Crathes Castle Garden | Image: Dougie Cunningham
As Scotland’s biggest single employer of gardeners, as well as caretaker to some of the country’s most spectacular designed landscapes, the Trust has the opportunity to set horticultural standards and pioneer new ideas. And nowhere is that truer than in sustainable gardening practices.

At the moment, our gardeners are experimenting with materials, exploring possibilities and looking afresh at traditional gardening practices. And this may mean that our gardens could look a little different in the future. ‘We may have to redefine how the gardens should look,’ agrees Ann Steele, Head of Heritage Gardening. ‘We always need to make sure we’re not losing anything of historical significance. But, at the same time, we’re trying to keep our sites relevant to the next generation.’

We are now considering even more carefully what we bring into our gardens, how we transport plants and materials, and how we use our own resources in the most sustainable way – from composting to energy capture. We have already introduced a peat-free policy; many gardens have swapped diesel machinery for rechargeable battery-powered equipment; and chemical fertilisers and pesticides are being reduced. ‘More of our sites have been managing successfully without herbicides and pesticides, which is really encouraging,’ says Ann.

Best of all, a new generation of optimistic, eco-minded Trust gardeners and gardening apprentices are joining the organisation, and they’re big fans of sustainability.

In future, native or naturalised plants could replace close-mown grass, and some lawns may be removed completely. Mown ‘strips’ could be limited to the edges of borders and drives, to help control unwanted grass seeds, or more time could be left between cuts. Trust gardeners have already experimented with wildflower meadows at Falkland Palace and Culzean Country Park. At Wester Kittochside Farm, home of the National Museum of Rural Life, there’s a ‘Coronation Meadow’, recognised under the scheme launched by the Trust’s patron, HRH The Prince Charles, Duke of Rothesay.

“We’re very keen to learn from the lockdown experience. Last year, having fewer acres of mown grass around our castles helped to reduce our carbon emissions.”
Ann Steele
Head of Heritage Gardening

Ann adds: ‘Some visitors said it was nice to see our landscapes looking less manicured because it would be good for wildlife.’

Chris Wardle, Gardens & Designed Landscapes Manager for the North-East, agrees: ‘Historically, grass would not have been cut,’ he says. ‘At Castle Fraser, for example, the sheep would have been grazing right to the front door! It’s time to gradually reshape expectations.’

Our gardening apprentices are also tackling sustainability projects head on. ‘One apprentice, Adam Penman, has been tasked with investigating how to turn Kellie Castle into a certified organic garden,’ says Ann. ‘The garden is already managed organically, but it would be good to aim for formal certification.’

A view of the side of Kellie Castle from the very lush and colourful garden. A narrow gravel path, lined by small box hedges, leads towards the castle, between beds of white and red flowers. The sky is blue.
Kellie Castle Garden

At Perth’s Branklyn Garden, apprentice Jamie Sinclair is exploring alternatives to the garden’s historical peat walls, while at Crathes Castle, another apprentice, Timothy Turnbull, is creating a new carbon footprint report for the gardens there so that future progress can be measured.

‘We’re looking at different areas,’ explains James Hannaford, Head Gardener at Crathes. ‘One area is the heating and insulation of the service buildings and glasshouse – maybe we could install a new kind of smart glass in future? We’re looking at water-harvesting and the capture of recycled water too, and tying that into supplying the greenhouse and bothy area. Even in a country like Scotland, water is an important resource, and climate change could bring dry springs and summers, as well as wetter winters. It’s really exciting to see our apprentices exploring something so relevant.’

A man in a light grey sweatshirt stands against a waist-high stone wall, with Crathes Castle walled garden behind him.
James Hannaford | Image: Dougie Cunningham

Trust gardens produce huge amounts of natural waste every year. Is there a way to reuse it? Simon Jones, Gardens & Designed Landscapes Manager for Glasgow and the South-West, believes so – and he has been researching worms.

‘The material that comes out of a wormery is quite spectacular,’ he says. ‘It’s called vermicast, and it’s full of plant hormones – it has everything soil needs without relying on fertilisers or pesticides. I’m researching how we can scale up the wormery process.’

A traditional way to improve soil is to mulch with chipped woody waste. This reduces weeds and retains moisture, but it can suck valuable nitrogen out of the soil. So, Simon has been exploring another potential solution: biochar. ‘If you process woody waste through a biochar kiln, you end up with a material whose structure is very similar to peat.’

“When you put [biochar] back into the soil, it boosts microbial activity, improves the soil structure, and puts the carbon back into the soil. It’s very simple, but so clever.”
Simon Jones
Gardens & Designed Landscapes Manager for Glasgow and the South-West

Inverewe produces large amounts of garden waste, and this has encouraged the team there to take composting to a new level. ‘We’ve invested in a wood-chipper and a special thermometer with a data probe, and we’ve given staff extra training,’ explains Operations Manager Martin Hughes. ‘The long-term goal is to use the compost to build up soil density, and to alleviate the effects of climate change. The topsoil at Inverewe is only 5cm deep in places and more rain could simply wash it away.’

Martin’s team have been trying to break down the compostable cups and plates from the café faster: ‘Everything is now shredded into 1cm pieces. We’ve also developed a special blend of green and brown waste that reaches the correct composting temperature (65°C) more efficiently. We check the compost beds regularly with the new thermometer, and it’s definitely making a difference – the compost we put down last winter looks wonderful. We hope Inverewe becomes the place to see how composting can work in a heritage garden.’

Another way to improve soil health is simply to stop digging – something that is being tried at several Trust gardens. ‘Every time you turn the soil, you release carbon dioxide into the environment,’ says Chris Wardle. ‘When you don’t till or dig the soil, beneficial micro-organisms increase which, in turn, helps to support bird and insect populations.’

A smiling man in a navy National Trust for Scotland fleece stands inside a glasshouse, surrounded by plants.
Chris Wardle | Image: Colin Heggie

The upper terrace at Pitmedden Garden looks very different this year, courtesy of a pioneering replanting project designed by award-winning landscape gardener Chris Beardshaw. It has been made possible thanks to funds from a major donor with a huge passion for both gardens and Aberdeenshire. Instead of mown grass and two box hedge (Buxus) parterres, the area will be replanted with what Beardshaw describes as a ‘floristic meadow’, bursting with colour from early spring right through to winter.

These two ‘deconstructed’ parterres feature a wide range of herbaceous plants, including ornamental grasses, seasonal bulbs and late-flowering, insect-friendly perennials like Helenium and Echinacea. At 30m wide by 120m long, the result will be the UK’s largest floral meadow. ‘The plants were all grown for us in Scotland, which reduces the “plant miles” and the environmental impact, and any new topsoil will be pesticide-free and peat-free,’ explains Chris Wardle. ‘It’s a modern approach but very sustainable too: there will be no staking or fertilisers, and very little cutting-down in winter – so there will be a seed source for birds and shelter for overwintering insects and ladybirds.’

He is looking forward to what lies ahead: ‘It’s a fantastic opportunity for the Trust to experiment: we can create something beautiful and sustainable, and at the same time change how we traditionally manage flower borders.’

A view of a floral bed at Pitmedden Garden, beside a gravel path in the foreground. Tall purple flowers grow close to the path edge, with red-pink flowers behind. They are surrounded by large ornamental grass plants.
A new bed at Pitmedden Garden

When peatland degrades or is damaged, the huge reserves of carbon dioxide contained within it are released into the atmosphere. Around 80% of our peatlands have already been degraded in some way and, as horticulture is one of the culprits, the Trust has a key role to play in demonstrating more sustainable practices. Our gardeners no longer use products containing peat, and our preferred suppliers are peat-free or at least peat-reduced in their growing processes. We’ve also reviewed our peat-based garden features. The peat banks at Inverewe are in good condition, but future refurbishments won’t use peat. Branklyn’s peat walls have greater heritage significance as an early example of their kind, and they’re also more visible, so any alternatives need to look good!

Encouraged by Head Gardener Jim Jermyn, garden apprentice Jamie Sinclair is looking at ways of phasing out the peat walls. One option could be to replace them with gabions – steel cages filled with organic material. ‘We could create some gabions, angled into the steep embankment, then fill them with rotting logs for stability, and chopped-up, tightly packed bracken and sheep’s wool,’ explains Jim. ‘That’s a marvellous substitute for peat.’

Jamie and Jim are also experimenting with a ‘building block’ made from newspaper and sheep’s wool compost, to replace the peat walls in future. ‘It would be easy for us at Branklyn to rest on our laurels – we have heritage reasons to use peat,’ says Jim. ‘But we want to explore alternatives by thinking outside the box.’

One easy win in Trust gardens is the use of rechargeable battery-powered equipment: ‘It’s something we can do right now, without any adverse effect on our gardens,’ says Simon. For example, at Crathes Castle all hedge-cutting in 2019 was done with electrical machinery. Many other Trust properties are also switching to electric kit, so the next logical step is energy capture. Photovoltaics (solar panels) are an obvious solution; but, as many Trust gardens have ponds and burns, there’s also potential for small-scale hydro-power and wind power. And at Crarae Garden near Inveraray, the use of a borehole to extract the garden’s ground-water could eventually lead to a ground-source heat pump to heat its glasshouses.

Or, why not ditch mechanisation altogether and use horse power? Tarzan, a logging horse, visited Inverewe in summer 2019 to help with some forestry work, proving that low-impact and sustainable methods of timber extraction are still relevant in the 21st century.

Find out more about Tarzan’s work

‘There’s a saying: “If you always do what you always did, you’ll always get what you always got”,’ says Chris Wardle. ‘Small decisions, however superficial, can have a big impact. The way we manage our historic gardens and landscapes has to change.’

Have you ever visited one of our gardens and wondered how you could recreate it at home? Or perhaps you’d like some expert help in adding some splashes of colour to your garden? Join our new ROOTS subscription scheme and receive a special pack every six weeks with gardening goodies to help your garden bloom – and six times a year the packs will also contain a packet of Scottish seeds for you to grow at home.

Plant your Roots today

Sign up now