Let the soil breathe.
Opening compacted ground can improve the movement of air through soil, supporting the oxygen supply roots need.
← All servicesHealthier trees
Tree care · Soil injection · Central London
Healthier trees
start below
the surface.
Give compacted roots more room for air, water and life.
From garden squares to private gardens, years of footfall and machinery can squeeze the life out of the soil. Specialist air injection offers a targeted way to improve the growing conditions around established trees.
Assessed and delivered by an independent soil-care specialist.
Open. Then support.
New pathways through the soil.
Illustrative two-stage treatment. Material injection is used only where appropriate.
Look after the roots. Look after the tree.
A busy city puts
pressure on its soil.
Compaction reduces the pore space roots depend on. Repeated foot traffic, events and maintenance vehicles can leave apparently healthy green space with a difficult growing environment underneath.
Help water move.
A more open structure can help rain enter and move through the soil, instead of collecting at the surface.
Make room for growth.
Reducing physical resistance can give fine roots a better environment to explore for water and nutrients.
A lesson from Kew Gardens
One old oak.
A new way of
seeing the ground.
The Turner’s Oak story shows why caring for a tree means caring for the soil beneath it.
During the Great Storm of 1987, the tree’s root plate lifted and then settled back. Its subsequent recovery helped Kew recognise the impact of compaction and make decompaction part of its care for mature trees.
Watch Tony Kirkham explain the lesson in this BBC World Service film.
Read Kew’s account ↗An independent educational example from Kew, not an AirTools project or a prediction for every tree.
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How soil injection works
Air opens the ground.
The next step helps it last.
A slender probe delivers compressed air below the surface. Where the assessment calls for it, porous material is then introduced into the opened fissures. The depth, spacing and treatment are chosen for your site.
01Place the probe
Treatment points and depth are selected around the roots, services and soil conditions.
02Open the soil
A controlled air pulse creates fissures within the compacted ground.
03Create new pathways
The opened structure gives air and water more routes through the root environment.
04Support the structure
Where specified, a second stage carries suitable material into the fissures.
Process illustrations reused from GardenSqua.re. Simplified sequence, not to scale.
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See the technique in action
A small entry point.
A change beneath.
The work happens below the surface, with local treatment points rather than stripping out the whole root zone.
This manufacturer’s demonstration shows air-assisted aeration and injection. It helps explain the technique; your specialist will confirm which equipment and treatment suit your trees and ground.
Ask about your site ↗More than a burst of air
The right material.
For the right soil.
Air injection and material injection do different jobs. Where an infill is appropriate, the specialist selects it to suit the soil, the tree and the intended improvement.
Biochar
A porous, carbon-rich material that can help retain water and nutrients and provide habitat for soil microbes. Its properties vary, so the product, soil pH and application rate matter.
RHS guide to biochar ↗Porous mineral infill
Materials such as Terramol, a calcined moler-clay granulate, can be introduced into fissures to help maintain open pathways. The specification should follow the ground assessment.
GardenSqua.re’s soil-injection guide ↗Tree care, beyond the treatment
Protect the progress
you make.
A healthier root environment is worth protecting. Treatment works best as part of a plan for how the space will be used and cared for.
- Review foot traffic, event layouts and machinery routes to reduce renewed compaction.
- Consider a suitable mulch and watering plan with your arboricultural adviser.
- Monitor the tree and soil over time, rather than judging success by an immediate change in the canopy.
For trees affected by construction or proposed works, the treatment must also fit the tree protection plan.
Understand tree protection areas ↗Your soil-care questions
Good decisions
start with context.
Can soil injection help a struggling tree?
It may help where compaction is a contributing factor. A thinning canopy, small leaves or poor growth can also have other causes. An arboricultural assessment should guide decisions about a declining tree, including whether it is safe to retain.
Does it replace drainage work?
Not necessarily. Improving soil structure may help infiltration, but a high water table, impermeable layers or drainage defects need their own assessment. The aim here is a better root environment, with drainage benefits where conditions allow.
Will it damage roots or underground services?
Treatment points, pressure, depth and materials must be selected for the site. Existing services need to be located and tree constraints understood before inserting a probe. Specialist air injection is a controlled method, not permission to work blindly around roots or utilities.
Can you reach a small Central London garden?
Tell us the narrowest clear access width, steps and tight turns. Our excavation fleet includes compact compressors, but a soil-injection referral uses the specialist’s own equipment. We check the proposed access with them before arrangements are made.
Who carries out the work?
An independent soil-care specialist. We handle your initial enquiry and ask before sharing it. The specialist assesses suitability, agrees the treatment and price with you, and delivers the work.
Central London · Specialist ground works