Arborist using a Soilpick to carry out root collar excavation

Airspade services

Traditionally, when excavation is required within the root zone of a tree, it has been recommended that hand tools are used to minimise damage to the tree’s roots. This manual excavation is time consuming and, even with care, often results in some degree of root damage. An Airspade is likely to be a more appropriate alternative.

An Airspade is a piece of equipment powered by a diesel compressor, which delivers a powerful jet of air. The jet of air displaces soil without damaging tree roots or buried services. Consequently, this makes the Airspade an ideal tool for excavating soil within the root zones of trees.

The main applications for the Airspade in tree care are soil improvement and root collar excavation. The tool can improve soil conditions within the root zone by relieving compaction and incorporating organic matter and other amendments into the soil.

The result of root collar excavation carried out on a lime tree that had the soil level raised around the base.

Root collar excavation is carried out on trees that have either been planted too deeply or that have had the soil level raised around the base. A tree’s root collar is the area where the roots join the main stem or trunk. Unlike roots, the bark of the trunk and root collar are not resistant to constant soil moisture, which results from direct contact with the soil. Research suggests that, over time, soil against the stem and root collar can cause bark necrosis which can increase the risk of the tissues being colonised by pathogenic fungi such as Armillaria mellea (honey fungus). It may also increase the occurrence of girdling roots. Removing the soil to the correct depth and backfilling with pea shingle may help to counteract these problems.

As well as soil improvement and root collar excavation, we are able to carry out air excavation of soil for a range of other purposes, including: examining root architecture, locating utilities, such as pipes and cables, root location to determine the position of piles and fence posts, trenching for irrigation and lighting installation, root mapping, assessing the extent of root damage or decay and root barrier installation.