Understanding Soil Health in Urban Tree Management

At the start of July, our Sales and Marketing Lead, Lois Smith (link to: https://www.treeworks.co.uk/lois-smith/) , joined Claire Harbinson (link  to: https://www.treeworks.co.uk/claire-harbinson/) , Principal Arboricultural Consultant at Treework, and Simon Parfey (link to: https://www.treeworks.co.uk/simon-parfey/) , Business Development Manager, to explore the critical role of soil in urban tree health.

The day began at a high-profile site where several young London Plane trees had failed to establish – some even replaced twice. This is a common challenge for the Soil Works team, led by Claire, who take a scientific, soil-up approach to diagnosing tree decline.

The team conducted:

• Visual inspections of the trees and surrounding topography
• Soil profile analysis via inspection pits
• Bulk density sampling to assess compaction that may impact root growth
• Chemical and microbiological testing, including root fragment analysis for mycorrhizal colonisation – a key indicator of soil health
• Samples were sent to our partner lab, SoilBioLab (link to soilbiolab.co.uk) , for detailed analysis.

These insights will help determine whether soil amendments or environmental interventions could support healthier tree establishment.

This location was a striking and all too common example of the challenges urban trees face. Set against the backdrop of a busy, high-profile landmark, the contrast was stark: some trees appeared healthy and thriving, while others (just a few metres away) were visibly struggling or had already failed. Sadly, this patchwork of success and decline is not uncommon in urban environments, where subtle differences in soil conditions, compaction, drainage, or even past construction activity can have a profound impact on tree health.

Later, the team visited a second site nearby to investigate another urban tree that had declined rapidly over the past two years. The same rigorous process was followed to ensure a data-driven diagnosis.

Lois said “I was amazed to see how much complexity lies beneath the surface – literally. The team’s methodical approach to soil analysis really highlights how vital it is to understand the environment trees are growing in, especially in urban settings where conditions can vary so dramatically within just a few metres.”

The Soil Works Treework team (link to: https://www.treeworks.co.uk/tree-planting/soil-advice/) is uniquely positioned to provide expert, practical advice on soil and tree related challenges. Their ongoing research partnerships, such as those addressing Oak Decline, reflect a commitment to biodiversity and long-term ecosystem resilience.

If you’re facing challenges with tree establishment or soil-tree health, we’d love to hear from you.