RHS Sustainability Strategy: Biosecurity Neutral by 2025

Nature Target 3 of the RHS Sustainability Strategy: Biosecurity Neutral by 2025

Assessment, management and control of biosecurity risks in our Gardens, retail centres and at our Shows and events; sharing our plant health knowledge with the wider gardening community to help protect the environment.

The RHS has committed to being Neutral by 2025 as part of our Sustainability Strategy. Sara Redstone, Biosecurity Lead in the RHS Plant Health team, explains what this means and how gardeners can help keep our plants safe.

What does this target mean?

Global travel and trade has more than tripled in the last decade, leading to increased movement of organisms from their habitats to new regions across the world. Imported plants and plant products, including wood, wood packaging and dunnage (loose wood or matting used to keep a cargo in position in a ship’s hold), are major pathways for the spread of harmful organisms. New threats to the health of plants and the environment are constantly emerging.

The word ‘biosecurity’ means policies, processes and practical measures used to prevent the introduction and spread of harmful organisms, such as those that cause plant diseases (e.g. fungi, bacteria, viruses, aphids, mites, plant parasitic nematodes) and plants. These actions aren’t just something for government and professionals to engage in. We all have a part to play in keeping our plants, gardens and landscapes healthy and protecting wildlife, businesses and livelihoods too.

Going ‘Biosecurity Neutral’ is about minimising the risk of introducing and spreading unwanted pests, diseases and other invasive species to the UK, in order to protect our gardens and green spaces. As the UK’s gardening charity, the RHS is committed to greening Great Britain and helping gardeners adapt to a changing climate, so we look for ways to identify, mitigate and manage the risks, where appropriate, not just avoid them.

This commitment to go ‘Biosecurity Neutral’ builds on the RHS’ six plant health principles, published in 2017, which placed an emphasis on assessing plant health risks associated with our activities in advance and taking measures to mitigate them; balancing risk with horticultural benefits; and prioritising research, knowledge exchange and development of plant health skills.

What have we done so far?

Created a dedicated biosecurity team who support and facilitate biosecurity best practice across our Gardens, retail centres, Shows and events
Developed policies, procedures and guidance to promote better biosecurity practices across the Society’s plant-related activities
Extended teaching and training of RHS staff, students, apprentices and volunteers in biosecurity and plant health practices
Developed plant reception units (quarantine) at each of our Gardens, which we use to hold incoming plants and semi-mature trees in for a period of time, where they can be monitored and regularly inspected, prior to planting in RHS Gardens
Piloted benchmarking our practices against a recognised national biosecurity standard, the Plant Health Management Standard, to help us drive the continual improvement we aim for
RHS Harlow Carr became the first public garden in England to be Plant Healthy certified, in January 2023. RHS Garden Hyde Hall first achieved certification on 5 January 2024 and RHS Garden Rosemoor on 2 February 2024. RHS Garden Wisley was certified on 21 November 2025 and RHS Garden Bridgewater was the final RHS site to be certified on 26 November 2025.
Increased our involvement in National Plant Health Week to inspire, encourage and empower everyone and to improve the understanding of plant health and improve biosecurity practices in the UK
We continue to engage with policymakers, in coordination with industry, to advocate for and ensure the sustainability of horticulture in the UK

What are we going to do next?

We will continue to work towards Plant Healthy certification across all five RHS Gardens and contribute to the improvement of the certification scheme, encouraging the adoption of the Plant Health Management Standard across the horticulture supply chain in the UK.
We will improve our resilience to biosecurity risks, by increasing preparedness for potential interceptions of unwanted organisms, and by undertaking research into sustainable management and control strategies for common pests and for pests not yet in the UK. This includes non-chemical plant protection products and new pest-resistant plant lines. We aim to engage, educate and raise public awareness around plant health and biosecurity risks in order to drive cultural change – for the benefit of people, plants, gardens and wildlife.
The RHS will develop an overarching collections policy for our Gardens that understands the vulnerability of plants and plant collections in public gardens to pests and diseases, and emphasises the importance of safe sourcing and procurement, promoting more in-house propagation.

Why should gardeners care about this?

Maintaining healthy plants and gardens ensures that their climate, and human health benefits are maximised. There are now more than 1,400 pests and diseases on the UK Plant Health Risk Register. The rate of introduction of new plant health threats is increasing every year, so increased awareness and vigilance is vital to protect plant life and all that depends on it. Some introduced plant pest and diseases, for example ash dieback, sudden oak death, box tree moth, horse chestnut leaf miner and oak processionary moth, have spread widely in the UK and are causing significant changes to our landscapes and horticultural practices. In addition to their impact on livelihoods and landscapes, the control and management of new damaging pests and diseases and other organisms can be significant.

For example, the total economic cost of ash dieback in Britain is estimated to be around £15 billion. An outbreak of Colorado Beetle in Kent, discovered in 2023 and currently under eradication, poses a significant threat to potato crops and to the UK potato industry, which is worth £1 billion per year.

An outbreak of Asian longhorn beetle in 2012 was successfully eradicated over a period of several years, at a cost of £1.9 million, with the loss of 2,229 trees. The management of invasive species costs the UK economy at least £2.2 billion every year, but often has wider impacts, too.

The RHS is on a mission. We want to empower the nation’s 30 million gardeners to green Great Britain and make it a better, healthier and happier place to live. To do this, to meet the UK’s commitment to increase woodland cover, and to achieve so many other targets safely, we all need to practice better biosecurity.

By changing the way we source, move and use plants and plant products, together we can make a massive difference and reduce the risks of introducing or spreading destructive plant pests. Plant health problems pose a potential threat not only to our gardens and parks, but also to food security and vital ecosystem services. If we all play our part to improve biosecurity, we can help to reduce threats like these. This means understanding and implementing good biosecurity practices and helping to monitor and report any suspected damaging plant pests, diseases and invasive species.

Seven things gardeners can do to go biosecurity neutral

1. Source UK-grown plants: always use reputable suppliers. Plant health problems are most commonly introduced on new plants, plant parts and associated growing media (e.g. compost).

2. Don’t risk it: don’t bring plants, seeds, flowers, fruits or vegetables home from abroad, or order from overseas online sources, as they can harbour harmful plant pests and diseases or invasive species. Where possible, buy plants, seeds and plant products grown in the UK.

3. Be on the lookout: check plants, bulbs, tubers and corms for any signs of pests or diseases, ideally before purchase. If possible, grow them separately for several weeks to ensure they are problem-free before they come into your home or garden. If you spot unusual symptoms, contact the supplier or RHS Gardening Advice.

4. Promote plant health: choose the right plant for the right place and give them the right care for their needs. Plants that are healthy and thriving are more resilient to plant health problems, reducing their impact.

5. Keep it clean: cleaning garden tools, greenhouses and water butts reduces the likelihood of providing a refuge for plant health problems. If you like to visit gardens, parks and woodlands too, please clean your shoes before and after you go. Garden waste affected by plant health issues should be disposed of carefully, in most cases via council green waste schemes.

6. Monitor plants in your garden and home: checking plants regularly means plant health issues can be addressed before they cause too many problems. Report unusual symptoms to UK Plant Health Services or talk to RHS Gardening Advice.

7. Encourage biodiversity in the garden: this will promote a wider variety of beneficial organisms such as insects, fungi and bacteria, which will help you by reducing populations of less wanted visitors. Tolerate some damage and avoid any use of pesticides, which are usually indiscriminate and kill beneficial organisms too.