What is the future for weedkillers? A horticultural consultant’s view…
The shift toward integrated pest management (IPM) in public landscapes is about far more than getting contractors to work differently, or banning glyphosate and expecting things to carry on as normal. Any suggestion to this effect is simplistic, and if we want to move away from using chemical weedkillers, the subject needs to be addressed as the nuanced and complex topic that it is. It is no understatement to say that this is about a fundamental reimagining of how we manage urban green spaces. IPM can deliver more sustainable and resilient landscapes that better serve both people and wildlife, and it is possible, but the journey will not be straightforward.
Effective communication plays a vital role in successful IPM implementation - making sure the general public understand why the appearance of our green infrastructure must change is a crucial part of the solution. Public landscapes often face scrutiny, and some IPM approaches will inevtably appear less manicured than traditional chemical-based management. Clear communication about management objectives and methods, including the likes of interpretation signage, helps build understanding and support for more sustainable approaches.
Let's look at the experience of our European neighbours. Whilst glyphosate remains an approved chemical in the EU, various countries have taken their own steps to reduce or phase out the chemical, with increased use of IPM and alternative methods. Here are the lessons we've learnt so far:
Common success factors across these countries include:
Strong political commitment and clear timelines
Investment in alternative equipment and methods
Staff training and development of new expertise
Public communication about changing landscape appearances
Design modifications to reduce weed-prone areas
Common challenges have included:
Higher labour costs and time requirements
Initial public resistance to changed landscape aesthetics
Technical difficulties with certain surface types
Weather-dependent effectiveness of alternative methods
Need for more frequent interventions
Luxembourg, Netherlands, France, Austria and Germany have introduced a range of restrictions or outright bans with - over time - a good deal of success. Belgium's approach has been on phased reduction, with significant success; whilst Denmark has effectively used an approach based on taxation and strong approval processes.
IPM is a systematic approach that combines biological, cultural, physical, and chemical tools to minimise economic, health, and environmental risks. In public landscapes, this means moving beyond reactive spraying to embrace preventative measures and natural control methods. Alternative methods, such as using hot water systems, are absolutely no silver bullet, but many can play a part in a successful IPM approach. The foundation of effective IPM lies in preventing pest problems before they emerge - this means differently designed planting schemes, increased practices such as mulching, and accepting weed growth within an acceptable range.
Appropriate plant selection means choosing species and varieties that demonstrate natural resistance to common pests and diseases. Equally important is maintaining optimal growing conditions. Maintaining diverse planting schemes helps prevent pest populations from exploding, as many pests are species-specific. Changing our planting schemes is something that will take many years, and will also require acceptance that all established ornamental landscapes require ongoing successional renovation attention.
Mulching suppresses weeds and supports beneficial soil organisms that can help control soil-borne pathogens. It is important to realise that mulching does not completely suppress weeds, nor is it intended to - but it helps, and it makes mechanical maintenance easier.
Natural predators and parasites play a crucial role in pest management as part of a biological control approach. Creating habitats that support beneficial insects, birds, and other wildlife helps establish natural control mechanisms. This might include installing bird boxes, maintaining areas of longer grass, or incorporating specific plants that attract predatory insects. Understanding these ecological relationships allows managers to work with nature rather than against it.
Long-term change requires a strong will, and it may need to be accepted that come chemical use will be part of that. An outright ban may produce such a violent reaction by the public around what their green spaces look like, that it is counter-productive. Considered and careful continued use of chemicals means choosing the most selective products available, timing applications carefully, and treating only affected areas rather than broad-spectrum spraying. Importantly, we must not simply jump to any old alternative simple beacuse glyphosate has become the bogeyman - many weedkillers are much, much worse! Chemical use should always be part of a broader management strategy, not the default response to pest issues.
IPM requires systematic monitoring and record-keeping. Regular surveys help track pest populations and their natural enemies, while documenting interventions and their outcomes builds an evidence base for future management decisions. This data-driven approach allows continuous refinement of management strategies.
Let's not shy away from the complexities of this issue, nor use it as a stick to beat the grounds maintenance industry on the head with. This is a societal issue with widespread implications - we are not going to find an easy solution, but let's not allow a polarised debate to prevent genuine progress.
Profile:
Tom Angel is a horticultural consultant working across the UK. Tom is a Chartered Horticulturist, Master of Horticulture (RHS), former branch chairman of the Chartered Institute of Horticulture, and worked previously as a landscape maintenance contractor. For a copy of the full dissertation please email tom@tomangel.co.uk.
To discuss any aspect of landscape consultancy or biodiversity-focused planting design, give Tom a call on 0141 432 1141 or email on tom@tomangel.co.uk