Large Trees In Backgreens
We have received several questions from concerned residents around sites we are supporting. This leaflet has been prepared by ECBA to provide some background information and advice relating to trees in tenement backgreens. Ultimately, it is the residents which live around the backgreens, not ECBA, who make the decisions as to whether trees should be planted, reduced or removed.
History of Trees In BackgreensEdinburgh tenement backgreens were originally provided as drying greens. Many of the Victorian cast-iron washing line posts still stand, bearing washing to this day, though a good many were removed during the 1940s along with miles of iron railings needed for the war effort.
Over the last 50 years, changes in society have resulted in a reduction of the use of backgreens for clothes drying. In many cases this has led to an overall neglect in maintenance of the drying greens. Ash, sycamore, elder, buddleia and other trees have always been present in backgreens, blown in by the wind or carried in birds. Whereas previously, the young tree seedlings were pulled up as weeds, they have recently been left to establish themselves as large trees.
Ash and sycamore in particular as mature trees can gain heights of 15 - 20 meters, taller than the surrounding tenements. The maturing trees begin setting seed after only a few years, so that a single ash tree can soon give rise to literally hundreds of others in the immediate vicinity.
In many places, North American Lawson cypress trees planted to provide low level privacy have grown into tall, dark columnar trees, also reaching well in excess of 10 meters.
Diverging Attitudes to Large TreesTrees in backgreen spaces, however defined, are an emotive subject, with fervent supporters and opponents. Trees can be beautiful to look at, lend colour and form to the originally empty backgreens once merely grassed over or covered by concrete. Ecologically they are seen to be generally a good thing, absorbing CO2, improving the air quality, providing roosting and food for birds and other wildlife.
For many people living in upper floors, concerned with world deforestation and living in the city centre, the canopy of leafy trees outside their windows provides a restful scene, reassuringly fixing carbon emitted by our energy-hungry culture. However, there are downsides to big trees in backgreens and a number of good arguments for having fewer of them.
For those living on the lower floors, large tree canopies fill much of the sky, taking sunlight and warmth from the ground. Backgreens already surrounded by tall buildings lose the advantage of the open sky above them. Sunlight which could be growing grass, vegetables, fruit trees and bushes is being absorbed by the tree canopy above.
Cool, shady backgreens are less inviting as social areas in which to sit out and enjoy a glass of wine with friends of an evening, for example. They are also not so good for drying clothes. Trees shed particles and provide roosts for pigeons and crows with the greater risk of unpleasant deposits being dropped on clean washing.
Problems Caused by Large TreesSome species, commonly ash, sycamore and cypress can grow to the height of ordinary Edinburgh tenements. Their crowns can fill the sky taking light and warmth from the ground underneath and limiting growth of other plants such as vegetables.
Commonly establishing along walls and close to buildings (where they are less likely to have been trodden on or mowed etc.) trees force apart masonry, dislodging stones & ultimately making some structures unsafe.
Leaf litter accumulates in greater quantities as the crowns develop. Leaves can fill gutters and block downpipes, leading to problems as water shedding from roofs falls against stone masonry and damages buildings.
BiodiversityEcologically, ash (the most common tall tree in backgreens), sycamore and cypress are poor host species, with only a small variety of native insects, mainly aphids, feeding on them. They compare very poorly with species such as oak, silver birch, hazel and flowering fruit trees (rowans, apples, plums and pears).
The community backgreens advocated and designed by ECBA are places of increased bio-diversity, providing habitats and food plants for a greater range of plants, insects and birds than that provided by ash, sycamore and cypress.
There is a place for native ash and even the more recently introduced sycamore, but it is in open woodland, or more exposed areas (both species are remarkably resilient tolerant of cold, salt and wind). Tenement backgreens are suitable places for lower, garden trees - such as fruit trees and shrubs, allowing them to be warmer, more amenable for people and their children, places where vegetables can grow and clothes dried naturally using the renewable energy of the sun.
Reaching A CompromiseECBA is committed to encouraging residents to recover the use of their backgreen spaces, to be used as social spaces where children and adults can meet and recreate. ECBA is also committed to encouraging small-scale vegetable growing, as this together with composting of kitchen waste greatly helps towards cutting the climate-changing gasses CO2, methane and nitrous oxide.
However, in the interests of good community relationships, ECBA recognises the need for some compromise between residents keen on food growing and those who favour tree cover. Like all compromises, this will feel less than satisfactory to begin with for both sides, and will take time and patience from all parties.
This is particularly the case in Conservation Areas of the city, where any tree whose diameter is greater than 7.5cm (3”) (at a height of 1.5m above the ground) is protected until official consent is given. Any work to such trees, including removing twigs and overhanging branches, must be sought from the Council’s Planning Department.
The Council’s arboriculturists for consultation purposes are:
Graham Hinshelwood - graham.hinshelwood@edinburgh.gov.uk (tel: 0131 529 3919)
Steven Milne - steven.milne@edinburgh.gov.uk (tel: 0131 529 3531)
Removal or Reduction of Large TreesECBA of course does not propose or recommend the clear felling of tall trees in backgreens, and is sympathetic to those who love their tall trees, we also appreciate the beauty and the privacy afforded by them. However, we do consider greater all-round benefits can be achieved by the removal or reduction of a proportion of large shady trees, controlling their spread and introducing more appropriate species.
Ultimately, it is residents making up backgreen communities, not ECBA, who make the decisions as to whether trees should be removed or not. ECBA’s intention is to encourage better use of backgreens both socially and ecologically, and is happy to listen and give advice on these matters; or else to refer questions on to specialists such as tree surgeons and arboriculturists.
It is also advised that any tree work be undertaken carefully. Even relatively small trees are very heavy due to the amount of water contained within the trunks and branches.
Where trees or branches are being felled or dropped, be aware of phone and other service lines and any structures underneath that could be damaged.
If there are any doubts as to proceeding safely, it is worthwhile employing the services of a professional tree surgeon or arboricuturist. Community Backgreen Groups should be able to apply for small grants to help pay for these services, though spreading the costs between group members and neighbours will also make them more bearable.