Category: Street Trees

Winter-flowering Cherry – the Great Deceiver

You may have noticed – possibly with some alarm – the delicate, yet persistent blooms of the winter-flowering Cherry which have been flowering for months now. The snow and ice of last week hasn’t been kind to them and many trees in London previously in full flower are now sporting a wilted coat of brown petals, but look beyond these and more flower buds are on their way!

Flower power: Winter-flowering cherry of the ‘Autumnalis’ variety going for it in mid-December

A few years ago a trend began for planting early or late-flowering (depending on your point of view) Japanese Cherries as street trees, and in some parts of town two closely related cultivars, like craft beer outlets, seem to be popping up on every street corner. Look out for the white flowered Prunus × subhirtella ‘Autumnalis*’ and the pink flowered Prunus × subhirtella ‘Autumnalis Rosea’

Millennial: The pink blooms of ‘Autumnalis Rosea’ on a February afternoon

For the uninitiated, the sight of Cherry blossom in the depths of winter has been known to elicit strong reactions from concern for seasons going haywire, to global warming incarnate. But, although I wouldn’t want to deny these very real climate change phenomena for which overwhelming evidence exists, the winter-flowering Cherry could not in itself be defined as an indicator. It’s supposed to flower in mild weather from November through to April. And this season, trees in London have been particularly good, blooming consistently since November despite the see-sawing of temperatures within the space of a few days. So, despite it feeling wintry out there, there has not, until last week been a sustained cold patch and this appears to have been exactly what this tree likes.

Frostbite: Wilting blooms mingle with new, unblemished pink flower buds on the ‘Autmnalis’ tree

Which leads us to the question: why does the winter-flowering Cherry flower in winter? The short answer is it has been bred to, its flowers are not filling an environmental niche to take advantage of a winter flying bee, it’s flowering because humans wanted something to cheer them up during the gloomy winter months. Prunus × subhirtella is known only from horticulture with Japanese origins disappearing into the mists of time. It is sometimes also called Prunus subhirtella – note: no ‘×’ denoting hybridity – it’s unclear (as with many other ornamental cherries) what parent species have hybridised to create our tree. Sometimes too, it is called Prunus pendula, an appellation most commonly ascribed to another cultivar, the spring-flowering weeping Higan cherry. This though seems to be sloppiness and it should properly be called Prunus × subhirtella ‘Pendula Rosea’.  Something else to look out for in Winter Flowering cherries is the last flush of blooms appearing in April with the leaves. These flowers differ from those of previous waves in having stalks – winter blooms are stalkless (or sessile).

Interestingly one of the world’s oldest Cherries, the 1,000 year-old ‘Miharu Takizakura’ in Fukushima province, is a weeping Higan and is often claimed to be the ‘most beautiful Cherry tree in Japan’. This is a cultivar unknown as a London street tree, but it may bode well for the longevity of the trees we do have, not to mention their long term potential for craggy good looks.

Dessert course: Delicate pink Cherry Plum (Prunus cerasifera) flowers of the ‘Nigra’ cultivar appear in March

As spring approaches, Winter-flowering cherries will be competing with other early flowering Prunus species, particularly the widely planted purple cherry plum (Prunus cerasifera) of either the ‘Pissardii’ (white blossom) and ‘Nigra’ (pink blossom) cultivars. If you’re lucky, you may see Almond (Prunus dulcis) with big pink flowers, Blireana plum (Prunus × blireana), with almost fluorescent pink blossom or another Japanese tree, Prunus × incamp ‘Okame’ again with pink blossom preceded by distinctive maroon coloured buds.

* The University of British Columbia Botanical Garden holds that ‘Autumnalis’ should actually be known by its Japanese cultivar name of ‘Jugatsu-zakura’

Chiswick walk

Street Tree Walks, Talks and Other Events

Since the launch of my book, London’s Street Trees, earlier this week, I have been asked about associated walks, talks and other events I’m doing. So I created a Facebook events page – something I never thought I would hear myself say. It seems like the easiest way to keep everything in one place. Do please follow and share, and of course, come to the events too!

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Safe Haven Books Publisher, Graham Coster (left) and myself at the launch in Marylebone

It was a full on week with the official Book Launch on Tuesday swiftly followed by a guided walk around Fitzrovia and Bloomsbury with Architectural Association members on Wednesday – my first sortie into the wilds of London with a group of architects! Next I had An Introduction to the Urban Forest, a talk and walk from City Hall and part of London Tree Week on Thursday.

Our route took us around London Bridge and Bermondsey where we found a Tree of Heaven under which was a commemorative plaque to Alfred and his remarkable wife, Ada Salter, whose ashes had been interred nearby. We went on to inspect the Strawberry Trees on Melior Street I last blogged about in 2011. I can report they have grown considerably, some have gone missing in the last six years, but the remaining trees are thriving.

And on Friday, it was Trees and Technology with the Woodland Trust, the Greater London Authority, TiCL and Curio. A fascinating helicopter view of some of the ways in which innovative technologists are working with trees. More about this in a future post no doubt!

The week finished with a hunt for Olive Trees in Westminster (didn’t see any) and a well-earned drink in a nearby pub close to a Chonosuki crabapple (Malus tschonoskii).

 

Five of the Best London Boroughs for Street Trees

From Hibiscus in Shoreditch, Golden Rain Trees in Osterley, and Bottlebrush trees in Pimlico, London has unexpected and fascinating street trees. Our urban forest, often under appreciated, is extremely varied and, what grows where differs around the city. So, which are the most interesting boroughs for a discerning London street tree admirer to visit, and why? Read on to find out about 5 London boroughs that, in no particular order, stand out…

1. Hackney

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Hipster Tree: Flowers of a Red Heart Hibiscus syriacus in trendy Shoreditch
Until about 20 years ago, Hackney was one of the less forested boroughs but around the turn of the millennium, it started catching up, and boy, did it catch up. Hackney now is a veritable arboretum: you can find streets lined with Kentucky Coffee Trees (Gymnocladus dioicus) in Clapton, Hibiscus (Hibiscus spp.) in Shoreditch, Wild Service Trees (Sorbus torminalis) in Stoke Newington and Scots Pines (Pinus sylvestris) in Dalston. The urban forest is relatively young here but what it lacks in maturity, it makes up for in diversity. There is something of interest at virtually every turn, and it will be exciting to see this part of town mature in the coming years.

2. Southwark

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Shard of Oak: Autumnal Red Oak (Quercus rubra) leaves in Southwark
Southwark is a big borough (by inner London standards), stretching from the southbank at London Bridge all the way east to Canada Water and south to Dulwich and Nunhead. Street tree planting is varied, and, like Hackney, you don’t have to go far to find something of interest. There’s a street of spectacular Yoshino cherries (Prunus x yedoensis) in Herne Hill, some of the biggest Tree of Heaven (Ailanthus altissima) specimens in London can be seen in Bermondsey and Magnolias (Magnolia spp.) are planted outside Borough Church. Southwark has pioneered some unlikely species too, including Persian Silk Trees (Albizia julibrissin) and, one of my favourites, the Strawberry tree (Arbutus unedo).

3. Hounslow

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Old Gold: A mature Golden Rain Tree in Chiswick
That long ribbon of a borough, Hounslow, has been planting great trees for years. It’s got everything, from stately Planes (Platanus x hispanica), classic Lime tree (Tilia x europaea) boulevards and landmark Cherry (Prunus spp.) avenues to being perhaps the best place to see mature Golden Rain Trees (Koelreuteria paniculata) in London. Of these elder statesmen, a tree right outside Osterley Tube station is an arboreal landmark, displaying beautiful coral pink new leaves in spring, yellow flowers in high summer, glorious autumn foliage and seed lanterns in the winter. There’s at least one tree in this borough playing host to Mistletoe too.

4. Islington

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My Cherie Amour: Lovely as a spring day, Bird Cherry in full flower, Islington
My home borough, so I might be a little biased, Islington is the part of town I know best. It’s the best borough for Caucasian Wingnuts (Pterocarya fraxinifolia), a fabulous spreading tree easily identified by tell-tale dangling clusters of little winged nuts, and is home to some other intriguing species. Islington was, of course, the first borough to plant Olive trees (Olea europaea) on the street – to reflect its Greek and Turkish communities perhaps? It is also home to some great Elm trees of various types including the Chinese Lacebark Elm (Ulmus parvifolia), the largest tree of this species in the country can be seen planted outside the Whittington Hospital. But perhaps what Islington is most noted for is ornamental fruit trees; dotted about the borough, the street tree aficionado can find rare pears (Pyrus spp.), notable Crab apples including plenty of Chonosukis (Malus tschonoskii), and unusual Yunnan Apples (M. yunnanensis). There’s also a good stock of flowering cherries including examples of the now rather out of fashion Bird Cherry (Prunus padus).

5. Westminster

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Frontline: Newly pollarded Plane trees separate Tate Britain from the Millbank Estate in Pimlico
Westminster plays host to the ‘Government Estate’, so has the job of keeping some of the most visited, filmed and photographed parts of the city looking green and pleasant. There are a lot of mature Plane trees in Westminster, as you might expect, adding to the grandeur of Whitehall and parts of the West End. But scratch the surface and you will find more interest around many corners. Westminster has pioneered the planting of Gingkos (Gingko biloba), a species well adapted to life in the busiest parts of town, and even in this most urban borough, English Oaks (Quercus robur) can be found outside Charing Cross and Pimlico stations. Perhaps the finest Mimosa (Acacia dealbata) to be found on the frontline can be seen in Pimlico and there’s even a street lined with Australian Bottlebrush trees (Callistemon citrinus)!

Stanfords

These trees and many more feature in my newly published book, London’s Street Trees and I shall be talking about the urban forest at Stanfords Map and Travel Bookshop in Covent Garden on June 5th. Please do join me!

 

 

The London Street Tree Publishing Event of the Year, Possibly

I have an announcement to make: my book, ‘London’s Street Trees: A Field Guide to the Urban Forest’ will be published by Safe Haven Books at the end of May.

Final Cover hi-res

This book documents my own journey of discovery, not just of the great variety of London’s street trees, but also their fascinating stories. I’m extremely pleased to include a Foreword from London’s Mayor, Sadiq Khan, who will face the challenge of improving our air quality during his term in office, I’m sure that planting many more trees in the city will be part of the solution.

To quote A.D. Webster, who wrote the – dare I say – ground-breaking book London Trees; Being an Account of the Trees That Succeed in London, with a Descriptive Account of Each Species and Notes on Their Comparative Value and Cultivation. With Guide to Where the Finest London Trees May Be Seen in 1920: ‘Nothing very remarkable is to be found in the way of street trees in London.’ Nearly a century later I can confidently report that this is no longer the case. I have counted well over 150 distinct species, and at least another 150 cultivars or varieties. I am sure there are many more than this and I am also sure this number will only increase.

Londoners need only walk a few minutes from their front doors to encounter a hugely diverse and endlessly fascinating urban forest. My book is a celebration of the forest, its diversity and its beauty. It is a guide to the many unexpected, even improbable, species to be found around the capital, from Anerley to Walthamstow, and an attempt to shed light on things many of us never knew about the trees on our streets.

Most people will be aware of London’s own eponymous street tree, the London Plane – in itself unique among cities – and no doubt many could recognise one, but according to the London i-tree eco project report, Plane trees account for less than 3% of London’s street trees. I hope this book will go some way to helping you identify the other 97%.

Here’s a few spreads from the book to whet your appetite:

Chequer This Out: Wild Service Trees can be found on London’s streets
Feature Rich: One of many articles about the urban forest
Trail Mix: One of four London street tree trails
You may want to read more, if so, you’ll have to wait until the end of May, but you can pre-order on these sites:

Amazon

Summerfield Books

Book Depository

Waterstones

I hope to do some events around the publish date including walks and talks which I will announce on Twitter closer to the time.

London’s Street Trees on the Map (well, most of them)

Some months ago I heard rumours about a London Street Tree map being prepared by the GLA at City Hall. Excitingly, that map is now live and has been for a couple of months. For those who haven’t yet poured over the fascinating insights into what trees can be found on London’s streets would be well advised to stop reading this and get over to the map now!

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Genus loci: The most common 22 tree types are mapped, and all the ‘Others’ are there too – they’re the brown dots…

Underlying the map interface there exists a vast database of information, no doubt hard won, wrestled from individual boroughs. Each borough is responsible for the trees on their patch and each has a team dedicated to their management. Perhaps not surprisingly then, each borough holds their own records for their part of the urban forest, and each borough uses different ways to gather and store this data, not to mention what data it actually harvests and holds. Therefore the feat of wrangling data from these various sources into a single dataset providing consistent information should not be underestimated – makes my brain hurt just thinking about it.

There are some black holes – for instance, Hackney and Haringey are two of seven boroughs that have yet to provide their data, but 25 of the 32 boroughs, plus the City of London and TfL have done and even with gaps, the potential of this map is becoming clear. Knowing what is planted on our streets is not only of interest to those who manage the tree inventory, this information can start to inform planning decisions, provide environmental insights and help shape policy to improve air quality. If there’s a correlation between levels of pollution and mature Plane Trees for instance, then this map could be a tool in that investigation right across the city. For me though, the most exciting possibility is the potential for public engagement.

The street tree data including location and species information is in the public domain and is released under an Open Government licence. It can therefore be used by third parties to exploit both commercially and non-commercially. And this is where the opportunities lie: imagine an app that can tell you what the tree is outside your front door, or the tree you walk past on your way to work? All possible with the data. Imagine walking up to a tree and discovering through your smart phone that it is a 150 year old Plane tree, it’s 33m tall and it’s one of 253,751 Plane trees in London, one of the most frequent trees in the city. This Plane tree stores CO2, soaks up pollution, moderates temperatures and has a financial value too. Imagine another app, this one educational, telling kids about all the minibeasts that make their home in an Oak tree outside their school or a Rowan tree on their street. It could tell them that an ancient pollarded Black Poplar tree in the local park was there long before the park and that it is a rare native tree that needs protecting. Another app could guide users on tree trails around Hampstead, Putney or wherever, it could allow the users to add comments about the trees on the trail, even add their own trail or check in at the Wembley Elm on Facebook.

And then of course there are more practical or nerdy applications, want to check out where all the Kentucky Coffee Trees are in London? Want to let your Local Authority know about the broken branch on a tree in your street? Want to see where the empty tree pits are? Want to get involved in community street tree maintenance?

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Big Apple: Every species is listed on the NYC map allowing users to easily locate their nearest Amur Corktree (Phellodendron amurense)

So, what do other cities do about mapping street trees? New York appears to be leading the way with their recently launched map. It is worth noting that New York is in a very different position to London in that one city-wide body manages the street trees ensuring the data wrangling issues faced in London just don’t exist, so they have the luxury of focusing on visualistaion and functionality. New York’s data is real time, users can register and once logged in, favourite individual trees and get involved with community street tree activities like planting and maintenance.

Melbourne’s map, like New York’s, allows users to zoom in almost to street level, but it only covers a relatively small area of the city centre. As reported in media around the world, users can email trees in Melbourne which while possibly a bit odd has clearly caught the imagination of many.

The London Street Tree map and especially the data underpinning it are tools that could help us understand, appreciate and value the trees in London which in turn could make our lives richer and healthier. I can’t wait to see it show all the street tree data, and with more detail too – exact species info would be great to see.

The Greening of Kings Cross

“I can’t understand why anyone would want to buy a house on such an awful street.” These words, uttered by a passer-by 15 years ago, acted as a red rag to a bull for Wharfdale Road resident John Ashwell. A typically busy inner London street of multiple building styles and ages, Wharfdale Road connects York Way with Caledonian Road in Kings Cross. 15 years ago Kings Cross was a by-word for drugs and prostitution and was a very different place to the developed destination it has become.

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Front Line: Wharfdale Road as it looked in 2002 just after the first trees were planted (Pic: John Ashwell)

Kings Cross forms an arc spanning two London boroughs from Pentonville Road to Marylebone Road with York Way at its apex. The Islington half was the crime hotspot while the Camden half was the dereliction centre of London. Now the Camden portion boasts a transformed St. Pancras station and the new Granary Square ‘quarter’ around Central St. Martins. Without the dubious benefit of a masterplan, landscaping and massive new developments the Islington half has had to make do with piecemeal private developments and community initiative. And this is where John, the original Kings Cross residents and the local authority came in.

John, a landscape gardener by trade, fired up by the throwaway remark overheard outside his front door, set his sites on no less a task that the beautification of Kings Cross starting with the planting of street trees on Wharfdale Road. Planting started after John raised money from local residents and the council released S106 funds enabling one half of a Cherry tree avenue. Over the next few years more money was released through public and private funding allowing the completion of the avenue planting. This second phase involved the narrowing of the road through incorporation of parking bays separated by tree islands transforming the street into the urban equivalent of a hollow way. All this has been achieved in the remarkably short time of 15 years.

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Tunnel Vision: Wharfdale Road as it looked in the spring of 2016 (Pic: Sarah Ward)

Over this time a strong partnership has formed between the community and the council who all had the same goal of planting more trees and cleaning up their part of Kings Cross. In Wharfdale Road they planted a cherry avenue of Prunus avium ‘Plena’, a double white flowered variety of the common cherry and Prunus maackii ‘Amber Beauty’ a golden trunked Manchurian cherry with single spiked flowers (much better for pollinators). Within this corner of the urban forest over 300 trees have been planted including Islington’s first Olive (Olea europaea) grove on Fife Terrace and, something I’ve never seen elsewhere – Bay trees (Laurus nobilis) on Caledonia Street.

Of course, the trees on their own have not transformed this once scary corner of London (it would be foolish to ignore the presence of CCTV cameras and the millions of development pounds pumped in), but they certainly make the environment pleasanter and they have definitely helped calm the traffic on Wharfdale Road. Perhaps too they have contributed to making the area more hospitable for people which has in turn resulted in a proliferation of cafés and restaurants who don’t need to think twice about opening onto the street.

The community partnership allowed residents to get involved with street tree selection and  planting giving them a sense of ownership of the trees in their neighbourhood and, coincidentally or not, Islington has recorded the lowest rate of sapling destruction in this part of the borough.

Staying Olive: Islington's first Olive street trees on Fife Terrace
Staying Olive: Islington’s first Olive street trees on Fife Terrace

And here’s the street view of Bay trees in Caledonia Street, bizarrely the restaurant they shade is called ‘Thyme’:

London Tree Week 2016

How exciting – next week, Saturday 28 May – Sunday 5 June, is London Tree Week! I’m sure this fantastic initiative from the Mayor will prove to be a great success.

There are a whole raft of activities organised by City Hall’s environment department to check out on the London Tree Week pages.

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Street thrill: Wild Service Tree flowering just off the Kingsland Road

Not to be outdone by Saddiq, I have also put together a somewhat taxing itinerary of a selection of London’s more unusual and overlooked trees like this thrilling Wild Service Tree (Sorbus torminalis) on St. Peter’s Way, N1.

You can find my listings on the tree-mendous TiCL app, available as  iOS and Android downloads.

I’ve listed 22 trees worth checking out all over London from Finsbury Park in the north to Croydon in the south and from Chiswick in the west to Canary Wharf in the east, the app will use your location to tell you where your nearest trees can be found.

Once you have the app downloaded, follow these steps to find my listings:

TiCL app
Tree steps to enlightenment: 1.Click the search button 2. Type ‘Street Tree’ in the Keyword field 3.Click on ‘Street Trees of London’

Also not to be missed is the London Tree Week photography competition. I shall be out snapping and posting with the hashtag #LondonCanopy next week, so please do keep an eye on my Twitter account for daily tree snaps like this one:

Long may London Tree Week continue.