Visitors to Kensington Gardens during half term week (27 - 31 October) are likely to see work underway on significant improvements to the historic treescape of the park.
Thirty-nine poor quality lime trees are being removed to prepare for planting replacement trees early next year. The trees form part of the Great Bow, a double avenue of trees encircling the Round Pond, developed by the great landscape designer Charles Bridgeman between 1726 and 1733. They were planted in the late 1980s, to replace trees lost to Dutch Elm Disease and the storms of 1987 and 1991.
Unknown to The Royal Parks, the clone selected at the time was of poor quality with a weak branching structure. The majority were also planted too deep, leading to poor growth. Ultimately these trees will suffer from limb and root failure, so will not make a long term contribution to the future treescape of Kensington Gardens.
Royal Parks aboriculturist Ian Rodger explains more:
"The clone of Lime we are removing develops three limbs from the same point on the trunk, about 3.5 metres from the ground. As the tree grows, this will form a weak point which will not be able to support the weight of the future crown structure.
"When a tree is planted too deeply it will often respond by developing new roots from the lower trunk as the original roots slowly die. These responsive roots keep the tree alive but are very poor at anchorage; several of these trees have already blown over.
"We will remove all 39 trees, excavate the sumps, re-condition the soil in the planting pits and replant with new trees, all 14 to 16 inches girth at one metre from the ground. This form has a better branching structure and habitat and is the most common clone selected in subsequent planting in this area."
The new trees will be planted in February 2015, weather permitting. They are expected to catch up with their neighbours in 10 to 15 years, reaching full height in around 50 to 75 years. Ultimate life expectancy is at least 150 years.
All the woody material form the removed trees including the stumps will be chipped and composted on site. This composted wood chip is very valuable and will be used to improve the soil around other trees in Kensington Gardens.
A healthy tree can be seen in the foreground on the left. The tree to the right is of poor quality and will not be able to support its own weight as it grows.