5 November 2018
Ahead of National Tree Week, City of Trees shares the fascinating history behind the Native Black or ‘Manchester’ Poplar which grew out of the industrial revolution. Once a familiar site, and one of few trees to survive the heavy pollution, these Manchester-marvels are now a much rarer find!
Around the turn of the 19th century massive unplanned urbanisation was brought on by a boom in textile manufacture.
Cotton became king in the decades after the world’s first steam-driven mill was built in the city in the late eighteenth century by industrialist Richard Arkwright.
Manchester and the surrounding towns proved to be ideal locations for production because there was a constant power supply in the fast-moving rivers that flowed from the Pennines.
Manchester was the first industrial city in the world and as manufacturing expanded and thrived, the city also became one of the most polluted.
By 1913 many trees had died, suffocated by a layer of soot, sulphur-dioxide and other air pollutants, created by burning vast amounts of coal in factories across Greater Manchester.
The effects of different pollutants do different things to trees however they would have caused damage to leaves and reduced the trees ability to photosynthesise and made them more vulnerable to other diseases and pests.
It would have been noticed that native black poplars tolerated these difficult conditions and were relatively easy to propagate (reproduce).
These were known as trees that could withstand the extremely poor air, and this unique ability to survive air pollution allowed the Manchester Poplar to thrive. It became a tree that championed the industrial landscape while giving people a green escape from the factories.
In the 1930’s, following the Wall Street Crash, Britain entered the Great Depression and unemployment soared.
Something needed to be done to give local men jobs so The Government and Manchester Parks and Cemeteries Committee collaborated on a project termed Unemployment Relief Works. Men were hired to go out every day on bicycles with a bunch of poplar saplings and a small iron bar to create holes in the ground.
The men would ride round far and wide and wherever they found a suitable green spot they would poke the stick into the ground and slot in a cutting.
This led to Manchester Poplars popping up on parks, towpaths, fields and village commons throughout the city region.
At the height of the planting efforts, some 25,000 plants were produced in a single year at a local nursery.
Unfortunately this most Mancunian of trees is now a very rare sight.
Since the summer of 2000, a virulent disease hit the Manchester Poplar which in most cases led to the death of the tree within 5 years.
This disease is an airborne fungus - poplar scab (Venturia populina). Many thousands of trees have been killed or removed because they became unsafe. There is no effective treatment for the disease and because the Manchester Poplar is one clone, there is no genetic diversity in the Manchester population.
Another reason why there is so few Manchester Poplars now is that as the city grew, its natural habitat- the flood plain – was slowly drained in order that for the land to be cultivated.
As the city devoured its natural home the tree needed to find a new one in the urban sprawl. Sadly, the Manchester Poplar has struggled to produce healthy seedlings – trees of both sexes are needed and even when present, viable seeds/seedlings aren’t often produced.
The female tree creates masses of white fluffy material that surrounds the seed allowing it to disperse long distances. Though this might be a very effective method of spreading genetic material far and wide, it made the female variety very unpopular with urban gardeners, municipal planners and farmers. This led to only male trees being planted creating a very low genetic stock in our trees today.
At the same time, faster growing and more ornamental poplar hybrids were being introduced. This led to the Manchester Poplar and native black poplar in general, rarely being planted commercially.
Also as the native tree flowers at the same time as the cultivars it has led to significant hybridisation, again reducing the numbers of true wild poplar.
It was estimated that between 5000-7000 of these trees remained in Britain in 2000, with a vast majority of these occurring in Greater Manchester. However, by 2005, half of these had to be felled due to a blight of Poplar Scab disease.
Before the trees began to decline, Black Poplars of all varieties were used for their timber as it was well-known for its fire resistant and shock absorbent properties.
Young pollarded branches were used for fencing and ladders, and older branches were cut for flooring and frame timber. It was a very valued wood and this is immortalised in an old anonymous English rhyme:
“Cut me green and keep me dry,
And I will oak or elm defy”
Its uses even extend to the medicinal applications; in the 15th century balsam from the buds was used to treat bruises and inflammation. From the 17th till the 19th century water found dripping from hollows was used to get rid of warts, and in the early 20th century it was a known practice to tie a lock of hair to a branch to cure a shaking fever.
To this day modern herbalists commend the tree for its healing properties for arthritis, bronchitis and haemorrhoids.
It is not known how many true ‘Manchester’ Poplars there are left in the UK, let alone the North West as they are very hard to ID against other strains of non-native Black Poplars.
Advances in molecular analysis means they can be identified in a lab-based setting, however identification in the field can still be difficult.
There is a confirmed specimen of Manchester Poplar in the British Museum, collected in 1915 from near Mauldeth Road Station and Ladybarn Park.
Manchester’s native black poplar trees are of national importance, and many are coming to the end of their natural life span.
With its roots firmly in Manchester’s history as the heart of the industrial revolution, these trees need to be celebrated and their heritage revealed.
It is believed a few good specimens remain in Alexandra Park, Whalley Range and Crumpsall Park, as well as St.John’s gardens.
City of Trees is looking for locations to plant native black poplars in damp, wet conditions, ideally flood plains. Get in touch if you have any information to share about the history of this tree or have a possible planting site!