Crathes Garden blog #20: New Year resolutions

Thinking about bark and its idiosyncrasies inevitably leads to thoughts of the giant redwoods (Sequoiadendron giganteum) and their spongy bark. The bark in ancient specimens of this species can be 60cm thick – the thickest known of any tree. At Crathes it provides roosting sites for treecreepers. Always ready to be side-tracked, I ponder on the redwood family. According to the Collins Tree Guide, the ‘Taxodiaceae is a family of 17 primitive conifers, often gigantic and with spongy red bark. They survive in scattered montane populations in both hemispheres’. [1] The story of these trees can be of legendary proportions: the living fossil dawn redwood (Metasequoia glyptostroboides) was discovered growing in Hupeh, China during the Second World War. By means of academic co-operation between Chinese and American botanists desperate to safeguard the tree from extinction, seed was sent to the Arnold Arboretum in Boston in January 1948. Here the seed germinated quickly and was distributed throughout the world. Crathes was among those that received early seed, and two of the trees survive in the Woodland Garden although the trees tend to do better in warmer climes.

Quite a few trees in the redwood family grow at Crathes. The giant redwood is common about the castle and some were planted in the 1850s when it was first introduced to Britain. Although its wood is brittle and useless commercially (which makes the early reckless logging in its native California heart-breaking to read about), it is easy to grow and looks majestic when planted around grand estates. It doesn’t blow over because of its buttressed trunk, but, as we saw in Storm Arwen (see my earlier blog: American giants and English oaks), it can lose limbs in a very dangerous way. The coast redwood (Sequoia sempervirens) is often confused with the giant redwood, although the needles grow quite differently. The two are rivals in the claim for the world’s largest tree. The giant redwood can live for more than 3,000 years, but the coast redwood coppices naturally and can sprout afresh, even after forest fires have reduced the parent tree to a blackened stump ... which means it might go on forever. Both species have adapted to wildfires and in fact need the heat and the fertilizing ash to regenerate, but the recent, frequent, extreme wildfires are threatening their survival as they leave no time for recovery.

The swamp cypress (Taxodium distichum) is also native to North America – from Texas to New Jersey – and has been known in Britain since the 17th century. I find it difficult to distinguish from the dawn redwood; the two look similar and both are deciduous. However, in the dawn redwood the young shoots and needles are opposite in arrangement, whereas in the swamp cypress they are alternate. A small swamp cypress grows beside the Woodland Garden pond. For many years it looked to be dying, but when surrounding shrubs were cleared it took on a new lease of life.

Across the other side of the world, three species of the Athrotaxis genus (part of the cypress family) are found in Tasmania. The large Athrotaxis laxifolia that grows just outside the garden gate at Crathes is over 100 years old. In 1922 it was identified by W J Bean, curator of Kew Gardens. In 1937 it was still a small specimen but can just be seen in a Country Life photograph. A small specimen of a rarer species, A. cupressoides, grows in the Woodland Garden. The third Athrotaxis species, the King William pine (A. selaginoides), is probably too tender to grow at Crathes.

Going north to China, the redwoods from this region are represented at Crathes by the previously mentioned dawn redwood (found near the East Lodge) and the Chinese fir (Cunninghamia lanceolata). A young attractive Chinese fir grew in the Woodland Garden for a while, but was felled by a falling oak limb some years ago.

Japan gives us the Japanese red cedar (Cryptomeria japonica) and the Japanese umbrella pine (Sciadopitys verticillata). The red cedar grows next to the Taiwania cryptomerioides near the Millpond, and their needles have a similarity that is reflected in the species name of the Taiwania. The umbrella pine thrives in Caroline’s Garden.

The weather and transport problems kept me away from Crathes for much of December; the only days I managed a visit were either gloomy or wet. The floods of mid-November (a month’s worth of rain fell in less than two days) have concentrated efforts to improve drainage in the Rose Garden and in the doocot pool. The path that slopes down to the summerhouse in the Rose Garden has been repaired many times after excessive rainfall and, if I remember rightly, as recently as last year. This time, the team have built a soakaway to channel the water away, using pebbles found on the estate and probably sourced from the River Dee many years ago. The camber of the path has been altered slightly and the edging stones have been reset.

Mike and Steve have been working on the doocot pool, which was built to give focus to the little statue of a putto (young boy) and turtle that had been gifted to the Trust in the 1960s by Lady Burnett’s sister, Elizabeth Carr. James thinks that excess water from the leaking pool and a defective overflow caused the death of the lovely Cornus controversa ‘Variegata’ (wedding cake tree) in 2019. The Lonicera nitida hedge that surrounds the pool is to be removed and replaced by box. L. nitida only looks good if it is cut frequently – maybe as much as three or four times a year – so its removal has been planned for some time. All these improvements will hardly be noticed by the public but they are essential to the health and maintenance of the garden.

In the glasshouse, Joanna is looking after 14 boxes of yew cuttings. These cuttings have been taken from different yew trees in the garden and on the estate. Each is recorded and will be tagged throughout its life. James is keen to see any differences in survival and fitness of the cuttings. Some are likely to be planted to replace trees lost in recent storms. Yew (Taxus baccata) is one of the three native conifers of Britain; Scots pine and juniper are the other two. The sentinel Irish yews are of the same species, but are fastigiate and grow more vertically than the norm. All Irish yews are thought to have originated from the Florence Court estate in Northern Ireland.

Commercial forestry has now come to an end on the Crathes estate, as the contractors and their heavy machinery finish clearing the damage wreaked by Storm Arwen. The result is not a pretty sight, but the subsequent planting will be kinder to the environment and it is hoped that heavy machinery will not be needed in future.

Management of the Crathes estate has never been as important as it is now. Biodiversity and climate change are inter-related. A healthy ecosystem sequesters carbon; an impoverished one releases carbon. When nature is destroyed, so are we. The planet needs a New Year resolution in which we will all participate. Whether the 30×30 target (30% of land and ocean protected by 2030) is agreed upon at COP15 [held in Montreal in December 2022] is doubtful at this moment, as nations grapple to divide finances fairly and empower indigenous peoples to care for some of the most amazing biodiverse areas of the world, such as the Amazon basin. [2] As I finished writing this blog, news came of an agreement on 30×30. All the nation states of the world have agreed to it, with the exception of USA and the Vatican State who never signed up to the Biodiversity programme. These next seven years will be critical.

But how does such a small nation like Scotland contribute to the global picture? Solutions to these matters are complex, but co-operation, grass roots action and political will are as relevant to Crathes as much as anywhere. And that’s why I talk about beavers with the rangers. Beavers are drivers of biodiversity: with their dams come millions of insects and other invertebrates. Then, feasting on the abundance of food, come fish, amphibians, reptiles, birds and mammals. The beavers also reduce flooding downstream by holding back the water. Although they cut down some trees, more sprout. Farmers are often not so keen to reintroduce beavers because river banks are damaged as the wetlands spread. But that’s the crunch. We – gardeners, farmers, land and sea managers – have to make compromises to reach that 30×30 goal. We are not controllers of nature; we are part of nature, and nature will ultimately decide our fate.

As far as the rangers know, there are no beavers in the Dee catchment area at the moment, but I guess it is just a matter of time – a year, a decade? Although the Coy Burn is an ideal location for beaver activity, there is the matter of dogs. The Crathes estate is a haven for dog walkers, and dogs love nothing more than a swim in the burn. No-one knows how beavers and dogs might react to each other. Beavers have evolved with predators and are clever enough to have the entrances to their dams underwater, so there may not be a problem – it’s just one of the unknowns about beaver re-introduction. Crathes may not re-introduce beavers as a policy, but these bioengineers could well make their own way from, say, the Hill of Fare. And when they come, they will be here to stay and the world will be a better place. As I write, I hear news of the proposed introduction of beavers to the Loch Lomond National Nature Reserve. Maybe the Cairngorms will be next.

Updates

• Crathes has applied to the Just Transition Fund, which supports programmes that work towards net zero carbon. If we are successful, the water borehole project will go ahead, releasing the garden from using the public water supply.

• Hard frosts have hit the North East recently and stayed for over a week. James does not expect the outdoor bananas to survive this winter. The tree ferns and cardiocrinum lilies have been covered up. There have been problems with heating the glasshouses as well.

• My own New Year resolution is to get one, maybe two, apple trees planted and to start experimenting with a mini meadow.

[1] Owen Johnson & David More, Collins Tree Guide, Collins, 2004

[2] An article in The Guardian in December 2022 highlights the problems facing the Amazon. The United Nations website is full of relevant biodiversity stories.