05/03/2026
Greetings ! This post is about beauty and the beast, but in reverse order.
I hope you're all keeping well. I'm keeping busy as usual, visiting properties around the Humber region. I don't talk to you about trees much, but sometimes they form an important part of an inspection, particularly if they are affecting buildings or drains, and I am occasionally called in to carry out tree proximity surveys, which can also be useful when there is disagreement between neighbours about the impact a tree on a property. I was carrying out an RICS Level 3 Home Survey at a big old house in Beverley recently and came across a couple of interesting trees, neither of which are currently affecting the property, but one of which will almost certainly do so in the future!
The first tree was a Tasmanian Blue Gum tree. There are 29 different species of this tree, 17 of which are only found in Tasmania itself. The most common species is the Eucalyptus globulus, which is the species I found in this garden. Essentially, it's a Eucalyptus tree. As you will know, these trees are favoured by koala bears, although their preferred species is actually the Eucalyptus viminalis, but they are happy to eat from my tree also! Sadly, there were no koalas in the garden during my visit. My tree is a monster of the gum tree family, although not quite the largest - that honour goes to the Eucalyptus regnans, otherwise known as the Mountain Ash, which is the tallest flowering plant in the world and reaches over 100 metres in height, the length of a football field!
The important information about my tree is that it is a very high water demand species - it can consume huge amounts of water - and it has very deep root systems, often being referred to as the 'thirsty' tree. It can grow up to between 90 metres in height and is both one of the fastest- growing and one of the tallest tree species in the world. Why is this in any way relevant? Because thirsty trees remove water from the soil in the ground and, given that most of the superficial subsoils around Hull and East Yorkshire are clayey, removal of water from subsoils close to a property's foundations causes the clay to shrink and dry, causing localised shrinkage of the soil itself. The reduction in soil volume means that the ground effectively shifts down away from the foundations, losing its capacity to support them (leading to subsidence).
Typically, the potential lateral root spread of high water demand trees in the UK is around 1.25 times the height of the mature tree, but this monster's root spread can be up to 2.5 times the height of the mature tree! My tree is approximately 12 metres in height and 9 metres from the house so, in theory, the tree already has the potential to damage the house's foundations, although of course root spread is random and unpredictable to some extent. Fortunately, there is currently no evidence of structural damage to the house, but I have recommended that the tree be pruned and maintained on a regular basis at no higher than its existing height, particularly given the possibility of another drought this summer, which will result in thirsty tree roots spreading further underground in search of water. Fortunately, no drains to the rear of the property, so no concerns there - drains are particularly vulnerable to collapse due to clay soil shrinkage, and old deteriorating drainpipes with small leaks are sometimes penetrated by tree roots desperately in search of water, resulting in gradual collapse.
The second tree was a Saucer Magnolia tree (Magnolia × soulangeana), a member of the Magnolia family. This tree poses no risk whatsoever to the property, and in fact my interest in this tree is of a more romantic nature. I would like you to take a look at the way some of the branches seem to make way for each other and sometimes actually alter their own shape to accommodate and make way for another branch. This beautiful, natural phenomenon is known as 'inosculation', sometimes referred to as 'self-grafting' or 'natural grafting', but the term comes from the Latin word osculari, meaning 'to kiss', which is why trees that do this are sometimes called 'husband and wife' trees or 'love trees'. The combined branches are known as 'gemels', from the Latin word for 'pair'. Form a dendrological point of view, when branches grow in close proximity, they often rub together in the wind. This friction wears away the bark, exposing the inner cambium layers. When these layers touch, the trees fuse together, allowing them to share nutrients and water. How perfect is that?
Thank you for your attention to these matters, and have a great day!
Oliver
