Air Spading / Air Excavation
An Air Spade is a soil excavation tool that uses compressed air to loosen soil while protecting underground utilities and tree roots.
At Kelly’s Tree Care, we use the Air Spade as a means to preserve trees. Applications for this air excavation device include soil remediation, root collar excavation, root pruning, and exploratory root surveys.
Tree health is dependent on soil health. Urban soils can become very compacted, limiting space for water and oxygen necessary for good root development. Soil compaction is exacerbated by the lack of organic materials such as leaf litter and by construction activity, for example. Air spading can be used to remediate compacted soils through soil aeration, vertical mulching, or radial trenching. Depending on the site conditions, we sometimes back fill the excavated holes or trenches with additional soil amendments such as compost, sand, or mycorrhizal fungi.
Root collar excavation is often necessary to determine the presence of girdling roots which are detrimental to tree health. Conventional hand digging at the base of the tree can be difficult when trying to avoid root injury. Conversely, the Air Spade quickly blows out the surrounding soil at the root collar and easily exposes any girdling roots which can then be properly pruned.
Exploratory root excavations are often performed and even required as part of development and construction projects. Sometimes roots need to be exposed prior to the proposed development in order to determine the extent of root loss due to excavation. The Air Spade can allow for this type of assessment without damaging roots. Toronto Urban Forestry recommends the Air Spade for preliminary root excavation.
Construction excavation within close proximity to trees often causes serious root damage due to machinery ripping and tearing away roots. Root pruning using sharp hand tools can significantly reduce root injuries. This can be easily performed once roots are exposed using the Air Spade.
Exposed trench showing undamaged roots. Properly pruned roots with partially exposed weeping tile.