Many thanks to Patrick Richardson for his interesting and insightful talk and to all those who came, it was a great session; thanks also to Karon Hollingsworth, GreenSpace for organising the event!
We learnt many things. Read on and check out the links that provide more interesting detail.
How to Establish the Age of a Tree
The age of a tree can be loosely estimated as its circumference in inches, expressed as years; eg. A hundred inches – a hundred years… In metric, take the circumference in centimetres and divide by 2.5 to give you the tree age. Not always true, but a good rule of thumb…
Inspiration from the Victorian age and beyond
Duncan Terrace Gardens is famous for its London Planes. The Victorians planted Plane and Lime trees because they were very tolerant of pollution; the leaves are able to trap particulates which are subsequently washed down to the ground when it rains, essentially filtering our air.
We tried to work out the age of the giant London plane trees in the Gardens – Platanus – [largely situated around 11 Duncan Terrace [DT], but another fine example at 1-2 DT; we estimated 150-200 years. To correlate, we dated some of the houses on the Terrace back as far as at least 1799; we know for much of the seventeenth and eighteenth centuries that the New River, which brought water into North London from Hertfordshire, ran the length of the Gardens, but in the mid-nineteenth century the space was enclosed , the river bed covered up and the space planted as gardens in about 1871 so it is likely that they are at least 150 – 160 years old and they may be 50 or so years older … We are going to contact Robin Hull a local London plane tree expert based at Highbury Fields.
Fine examples of the limes are to be found opposite 24-26 and 14-17 Duncan Terrace [DT] and of course elsewhere in the Garden, see if you can now spot the other locations. http://www.londontrees.co.uk/lime.html
The Tree of Heaven, or Hell?
Looking up through the trees around 7-8 DT was an amazing sight – the tree tops of the Planes merging with the branches of the impressive and fast-growing Tree of Heaven[ Ailanthus Altissima]. Its distinctive ash-like leaves and spreading branches are an impressive sight, but all is not as it seems, this species can be highly invasive, and is now rarely planted. Nestling between two dividing branches is the wonderful architectural birdhouse structure, Spontaneous City in the Tree of Heaven held high in the branches. https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/tree-heaven
The Sycamore [Europe], Sycamore Maple [US] : from the genus Acer
Known simply as the Sycamore here in the UK – trees are called different things in different places and why we sometimes resort to Latin….
Acer pseudoplatanus – translated simply means Like a Plane Tree.
The sycamore or sycamore maple, is native to central Europe and south-western Asia. It has a superficial similarity [leaves] to the plane tree [platanus genus], which is what led to its being named “Acer pseudoplatanus,” from the Greek “pseudo-” for “false.” https://en.wikipedia.org/wiki/Acer_pseudoplatanus
Acer campestre, or the Field Maple sits outside 5DT [photo below] and further down, on the Colebrooke Row side, two Cappadocian maples or Acer cappadocicum [at 1 & 3 CR] are easily identified by their leaves. Nearby them is another Prunus, the purple plum tree [now half it’s previous size because of a fungal infection – we may have to lose it completely…] and a large shrub with black berries which is a cherry Laurel – Prunus laurocerasus.
Snake-Bark or Acer capillipesis found at 19 DT– is a remarkable and distinctive snake-barked acer.
Hollies – male, female or other?
Other trees abounding in the Gardens [near the grassed area, opposite 27-28 DT] are Hollies – Ilex aquifolia – trees are either male, female, or both! Female trees bear berries and this is how they are identified. Other Holly types – variegated, are found elsewhere in the Garden, some in the woodland area [at 17 DT] and others right down by the City Road. https://www.gardeningknowhow.com/ornamental/shrubs/holly/how-to-tell-the-difference-between-a-male-and-female-holly-bush.htm
Up by the Grass on the Colebrooke Row side are native Hazelnut trees [opposite 27-29 DT] .
Tree or a Shrub? The long and short of it…
There are multiple examples of the confusion between a tree and a shrub in the Gardens, not least the pyracantha. Near the grassed area it is a huge orange-berried Pyracantha tree [at 26 DT], at the Duncan Terrace entrance [on the right and left as you enter] it is a mild-mannered shrub formed into a hedge; similarly, the red-berried Cotoneaster can be seen both as shrub throughout the Gardens and at 28 DT as a tree.
Cherry or Prunus is a huge genus of trees and shrubs, which includes the plums, cherries, peaches, nectarines, apricots, and almonds. Native to the northern temperate regions, there are 430 different species classified under Prunus. Many members of the genus are widely cultivated for their fruit and for decorative purposes.
The trees have distinctive bark – lenticels that sit in parallel rings around the trunk; these are used for gaseous exchange.
Prunus cerasifera, a purple-leaved plum tree sits at 23 DT, it has beautiful bark and rick purple leaves with pink blossom [I think! Check this Spring…] and another cherry at 1-2 DT, again on the CR side, although as above, this one is struggling badly and may have to be removed.
Another, unidentified large prunus is at 17 DT [on the CR side]; Then further down towards the City Road is a beautiful small spring-flowering, white cherry [at 10 DT on the DT side]; all to be identified over the next few weeks!
“Self-optimising mechanical structures” (Mattheck & Bremoer 1994).
In plain English, a tree! That is, something that will adapt to its conditions and surroundings!
Finally, Succession Planning……
Not just for boardrooms and companies! Over the coming months, we will be working with Greenspace and the Tree Department to ensure we have a succession plan in place for our trees; this will stretch forward over the next twenty years, so that as trees inevitably die, through age, disease or for other reasons, we can replace them in a sustainable and thoughtful way.