Place Overview & Scrutiny Committee
Subject: Tree Diseases in Brighton & Hove
Date of meeting: 14th October 2025
Report of: Chair of Place Overview & Scrutiny
Contact Officer: Name: Natalie Sacks-Hammond
Email: Natalie.sacks-hammond@brighton-hove.gov.uk
Ward(s) affected: (All Wards);
Key Decision: No
1.1 This report to Place Overview & Scrutiny Committee is to provide an overview of the tree diseases in Brighton & Hove, how they are currently being managed and what emerging threats exist for the city’s tree population.
1.2 Appendix 1 presents an overview of the risks affecting the city’s tree population and how the council is currently managing these, specifically in relation to elms and ash trees; and details future plans for further work.
2.1 Place Overview & Scrutiny Committee to note this report.
3.1 The country’s tree population faces significant risks, with Brighton & Hove particularly affected when it comes to elm and ash trees. The city is dealing with challenges such as elm disease, ash dieback, pathogens impacting horse chestnut trees, and the emerging threat of the elm zigzag sawfly. Additional threats, identified as priorities across Europe, have not yet become established in the UK but remain a concern. On average, one new pest or disease becomes established in the UK each year.
3.2 Brighton & Hove’s trees are both valuable and distinctive, making their protection essential. Trees provide vital environmental and social benefits: they reduce air pollution, help cool the urban environment, support health and wellbeing, offer opportunities for enjoyment of green spaces, ensure equitable access to nature, and provide habitats for wildlife.
3.3 The greatest threats to the city’s trees stem from imported tree stock, climate change, and limited species diversity. Strengthening biosecurity is essential to prevent the importation of potentially harmful tree stock into Brighton & Hove. The council has committed to more diverse tree species in its recent planting schemes, which ensure greater resilience for the city’s treescape.
3.4 Elms account for approximately one-third of Brighton & Hove’s tree canopy. The city is currently experiencing high levels of elm disease, and the council is leading extensive efforts to contain its spread, including delivering the largest elm inoculation programme in the UK. While the rate of infection is not currently accelerating, it has the potential to escalate rapidly without continued intensive management. The financial risk of replacing street elms is estimated at over £30 million within the next five years.
3.5 Ash dieback presents a significant challenge for Brighton & Hove, which is not containable. The only effective management approach is the removal of affected trees, with works prioritised for public safety, and particular areas of concern, such as woodland in Stanmer Park. Replanting costs are estimated at £18,000 per hectare over a 10-year maintenance period.
3.6 Appendix 1 provides more details on tree disease in Brighton & Hove and some of the emerging threats such as Elm Zig Zag Sawfly.
4.1 None specifically for this scrutiny report
5.1 None specifically for this scrutiny report
6.1 There are no direct financial implications arising from the recommendations of this report which is for noting.
6.2 The costs of managing tree disease and tree maintenance are included within the City Parks service. As at month 5 there is a forecast overspend of £0.100m, this overspend has been included within the cabinet report being presented at the October 2025 Cabinet meeting.
6.3 Consideration of the on-going revenue implications are forming part of the discussions for setting the 2026/27 budget and the overarching Medium Term Financial Strategy.
Name of finance officer consulted: Craig Garoghan Date consulted: 01/10/2025
7.1 This report is for noting and as such there are no direct legal implications arising from its noting. The Council is under a duty to monitor, control and where required, remove diseased trees to prevent the spread of disease and danger to persons or property. Any measures arising will need to be in compliance with these duties and may need further assessment of legal implications.
Name of lawyer consulted: Katie Kam Date consulted (02/10/25):
8.1 None specifically for this scrutiny report
9.1 None specifically for this scrutiny report
10. Health and Wellbeing Implications:
10.1 None specifically for this scrutiny report
11.1 Place Overview & Scrutiny Committee notes the report.
Supporting Documentation
1. Tree Diseases in Brighton & Hove – an overview.