by Katy Hawkins

This year, working with trees I’ve not yet worked with, I’ve been spending time getting to know them a little better. I’ve been reading what others know about them, and looking out for them whilst on wanders, learning to notice what makes them, them.

I wanted to share some of my research with you and links to interesting podcasts, books, relating to them and tips for identifying, ways of interacting and working with them.

FIG

A well known tree, in itself and, for the fruits it produces, the Fig is an incredibly ancient tree. Estimated to have been on the earth 60 – 80 million years ago, today it grows on all continents apart from the Antarctica. Both facts show us how skilled the tree is at adapting to a changing earth and environment, which is partly why we want to work with it here, in Birmingham.

Here is the best podcast I’ve listened to on the fig:

• podcasts.apple.com/us/podcast/fruit-love-letters/id1602743541

Featuring an interview with Mike Shanahan author of Gods, Wasps and Stranglers: The Secret History and Redemptive Future of Fig Trees.

I loved learning that a fig is technically not a fruit but a round ball full of flowers on the inside. Historically, a wasp would crawl into the ball to pollinate the flowers inside and lay their eggs inside. Then these new fig wasps would mate inside before eating their way out to pollinate elsewhere. 

The figs that we buy and eat from the supermarket have been developed by farmers over thousands of years and don’t always require wasps to pollinate them but if they do the female wasp will have zipped off before we eat the fig.

It talks about how and why figs have found themselves at the centre of creation stories in religions across the world – with the fig leaf often used as a form of clothing or cloth in many stories. In one tale, Mithra, a Persian god, is said to have emerged from a rock beside a sacred fig tree, and he is also described as having dressed himself in fig leaves.

And it talks of famous figs, the one Buddha sat under, or specific species such as the Banyan tree whose aerial roots shoot from branches travelling down into the ground to give extra support and give the impression of being a forest, in just one tree.

“fig tree” by fsse8info, CC BY-SA 2.0

WESTERN RED CEDAR

I definitely wasn’t confident on IDing a western red cedar – which is in fact not a cedar but a cypress tree.

The best top tip was knowing that the fern like, waxy, scaly leaves give off a fruit (some say pineapple) aroma – it’s a really vibrant cheeky scent and will help you distinguish between this tree and, for example, the lawson cypress with similar fern-like leaves (with its own distinctive bluish small cone like, woody fruits that also have an amazing smell, released on the piercing of the skin)

It’s got recognisably fibrous reddish bark but often taking the form of a hedge it’s not always so visible.

I learnt a lot about the tree through the Completely Arbortrary podcast episode on the tree –

The tree was sacred in the lives of the indigenous people of the pacific north west coast  – the area to which it is native – who respectfully alongside with the tree, cultures and spirituality tied up with it. Often referred to as the tree of life, it’s uses include canoes, totem and mortuary poles, clothing, hats, cradles, coffins, masks, combs, spirit whistles, with a practice of making such each part of the tree was used, so not to waste anything – including the roots used for cord, the needles extracted for teas. The tree however would not be felled but rather, fallen limbs would be used, else boards would be split from standing trees, using a wedge made of yew or antler. The tree being especially rot resistant – would keep growing and living intact – indigenous peoples’ only taking what was needed.

Notably it was recorded that few western red cedar trees were felled before European contact. 

“Western Red Cedar leaves” by David Prasad, CC BY-SA 2.0

ELM

Elm leaves have ridged surfaces (similar to hornbeam) with toothy edges (serrated). They don’t lay flat and are quite unruly looking (compared to the neat hornbeam).

The main way you can tell it’s an elm is that the base of the leaf is not symmetrical (you’ll know when you see one!)

As lots will know we very sadly lost most of the mature elms in this country during the 1970 – 1980s with the widespread outbreak of Dutch elm disease (DED), a fungal disease spread by a beetle which works to clog up the internal vascular system of the tree (that it uses to transport waters and sugars) and so killing it. 

It is really exciting to be planting elms this year, for the first year – the DED-resistant New Horizon cultivar – a hybrid between Japanese and Siberian elms (U. davidiana var. japonica and U. pumila)

The fungus, originating from Asia, however doesn’t affect elms native to parts of the Asian continent – the trees having co-evolved with the fungus and thus carrying a natural resistance. This is why we are now planting trees bred from Japan and Siberia.

One of the huge associated threats in the UK with loss of Elms was to the white letter streak butterfly, on which the tree depends for its primary (and non-negotiable) food source. 

It’s important to note that the New Horizon successfully works to support the butterflies, providing this vital food source for local populations replacing English elms.

One of the podcasts I found most informative on Elms and especially in relation to DED was a BBC Scotland programme: Saving the Great British Elm with David Shreeve and Max Coleman

https://www.bbc.co.uk/programmes/p0jwlhhf

Beyond the New Horizon and other comparable new cultivars – as the podcast shares – there are also many breeding programmes underway between elms that did survive DED in the UK – of which there are many more than had initially been thought. 

Interestingly the podcast talks about a difference between resistance (that they can be inhabited by the disease and fight it off) and resilient: that they perhaps have qualities that make it less desirable. In Scotland, it is the offspring of the DED resistance/resilient Elms that are being part of elm re-population efforts. 

The podcast also touches on a bit on our recent – european – history with elms: with its strong wood and nutritious shoots and leaves its provided valuable animal feed, wood for lock gates, or as blocks of wood under and supporting London bridges. 

Relating to planting disease resistant species – to note that in 2023 we excitingly planted a number of american ash trees – exciting as unlike a majority of our european native ash trees, they appear to be resistant to ash dieback (an air bourne fungal infection). The prognosis for ash is looking a little better than it did for elm in the 1970/80s but it is and will continue to be a monumental loss of the tree environmentally, emotionally, financially. 

Planted in Nechells and Bromford: get in touch if you’d like to know more about their whereabouts!

“Elm leaves” by Blondinrikard Fröberg, CC BY 2.0

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If you live in Alum Rock or Sparkhill and are keen to be involved in planting up some of these exciting, generous trees – get in touch!

If you have any fun tips, facts, ways of knowing these trees it’d be great to hear 🙂

Look out for another blog post about other trees we’re working with this year including the Judas tree.

We’re currently seeing record levels of human migration which is a direct result of a worsening climate crisis that disproportionately affects countries within the “Global South”¹. This Global North – Global South divide is based on GDP per capita, and is a division that is shaped by colonialism and its lasting impact. In extreme cases, entire communities are being forced to leave their homes as they suffer natural disasters, war and persecution. The place they were born no longer having the safety and conditions needed for them to thrive – or in some cases – survive. When we think about migration in a human context, it is defined by political borders. Lines drawn on a map.

Nature, however, is not bound by political borders even though we do use them to define what is ‘native’. Trees have what’s called a ‘native range’ which is the areas of the world in which they occur naturally, without human intervention. They are boundaried only by abiotic factors (nonliving things) such as climate, rainfall, availability of sunlight and topography. And increasingly by biotic factors (living things) that affect a tree’s habitat potential. We’re learning more and more about their deep relationship with (and often dependence on) other living things.

There are many species that here in the UK we classify to be native and some that are held up as symbols of British nationalism, the Common oak (Quercus robur) being a prime example. In fact, Common oak is also known (in Britain at least) as English oak for this patriotic reason. However, even these native species, throughout history, have moved and migrated and are migrating still. Oaks, like most species vanished from the UK during the last ice age and then took around 6,000 years to slowly recolonise the whole of the British Isles. ² 

In the UK we’re seeing hotter summers, milder winters and heavier, sudden rainfall known as cloudburst events. All of these changes can add stress to trees and fluctuate their habitat potential. In cities, where Urban Heat Island Effect can play a big part in how severe a drought is, we’re seeing a decline in some native species such as birch, rowan, willow and alder and they have started a northward migration toward cooler climates. At the same time we are seeing an increase in species that would otherwise have struggled here, now able to survive as winters that were historically too cold are now becoming milder. For orchard fans this means an opportunity for figs, almonds, peaches and many more.

A paper recently produced in partnership with Kew Gardens ³ in London showed how through plotting future climate scenarios for the UK against known existing native ranges for commonly planted tree species we can now see which trees are going to struggle first and which species will be beneficial migrants that can support our future urban forests. It’s predicted that the UK climate by 2090 will resemble the existing climate of southeastern Europe (think Romania, Bulgaria, Georgia etc.) and so by looking at species that are currently thriving there, or that are most common there, we can prioritise these species when planting.

Red markers indicate past, present and future UK conditions. Black markers show existing observations of species. The closer the red marker labelled “2090” is to the centre of the black markers, the better suited that species will be to the projected UK climate in years to come.

We still have a deep relationship and emotional connection to our historically native trees and will continue to do so even as their numbers lessen. To support our native and naturalised trees we should celebrate where they are adapting to climate change and we should explore new opportunities for habitat changes that could help secure their future. We already know that if we want silver birch or rowan in our cities or alder and willow along our river and canal edges we need to protect their habitat potential. If we can engage those involved in city planning and management we can increase rainwater harvesting, install better sustainable urban drainage systems and even underplant large climate resilient species with our native trees. 

However, we should be careful to avoid a native-only or native-first approach that risks our communities. We must also open our arms to the migrants – the future trees of our cities – to whom we will become more and more indebted for the health and well being benefits they bring. If we’re unable to accept help from new migrants to support the existing tree stock, we will lose huge numbers of urban trees, the benefits of which will take years to recover. 

At Birmingham TreePeople we’re planting a huge range of species each year that have proven abilities to thrive in the warmest urban settings, withstand drought and flood events and high levels of air pollution. This year we’re planting nine new Golden Rain Trees (Koelreuteria paniculata) which shows great potential to thrive in future UK climate scenarios.

Golden Rain tree (Koelreuteria paniculata) in flower. By Didier Descouens – Own work, CC BY-SA 4.0,

References

1. Independent Commission on International Development Issues, North–South: A Programme for Survival (London: Pan, 1980)
2. Lowe,  et al. (2005). Route, speed and mode of Oak Postglacial colonisation across the British Isles: Integrating molecular ecology, palaeoecology and modelling approaches. (Botanical Journal of Scotland. 57. 59-81.)
3. Kevin W E Martin, Henrik Sjöman – Evaluating urban tree population fitness for a changing climate: Using climatic moisture index (Trees, Forests and People, Volume 22, 2025)