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Dr Nicholas Cryer

Nicholas leads research on the application of sustainable water management techniques within domestic and public gardens, and the UK horticultural and landscape industry

What do you do?

I research the balance of water supply and demand in gardens and horticulture. This is to improve our understanding of the water needs of diverse types of gardens and different combinations of plants, focusing on how we can provide the right amount of the right quality of water at the right time. 

I also help to deliver on the water targets of the RHS Sustainability Strategy. The central concept is water neutrality, meaning we only use the minimum amount of water that is required, taken from a sustainable source, and we return water to the environment in a useful way. Examples include moving away from mains and river water sources to use rainfall and greywater.  

Increasingly, we are working to achieve impact by influencing the broader landscape through demonstrating how sustainable water management can be positive for people and nature.

“Water is life. The availability of water for plants and gardens provides many essential services, from cooling our air to absorbing air pollution, generating oxygen, and capturing carbon dioxide; all the while supporting our physical and mental wellbeing.”

Why is your team’s research important?

Our world is facing multiple crises, from climate change and the dramatic loss of biodiversity to profound societal and economic upheaval, and gardening can be integral to addressing them.

Gardens and plants are important to our culture, providing a connection with the natural world, promoting our wellbeing, and offering numerous services including air cooling, pollution capture, shade, and shelter. Water is essential for plants and gardens to provide these services.

However, the natural availability of water within our gardens is changing. We are increasingly experiencing the challenges of flood and drought. Additionally, public supply of water by utility companies is becoming restricted, as they also grapple with changing rainfall patterns, an increasing population, and the need to reduce the environmental footprint of water supply and wastewater treatment. 

There are two main things we can do: we can grow different plants that can cope with periods of water excess or deficit, or we can find ways to provide the right environment to enhance water availability so that we can continue to grow the current selections of plants. Change will be required, and I believe we need a bit of both approaches.

My role is to facilitate gardening and horticulture, and all the benefits it brings, by clearly showing how much water is needed to grow different plant combinations in different environments, and by providing knowledge and advice on how we can best provide that water.

Projects I’m working on now

All the projects I am responsible for support the RHS Sustainability Strategy; to be water neutral by 2030.

RHS Gardens:

  • Optimising our water use by using sensors to inform when and how much to irrigate RHS Gardens

  • Characterising the water use requirements of landscape and garden plants (read more on this project)

  • Building models based on water balance and plant physiology to optimise water use at landscape scale and deliver environmental services

  • Using greywater to demonstrate and promote alternative water sources for horticulture

Domestic gardens:

Supporting the horticultural industry:

  • Demonstrating best practices in water use at RHS Gardens

Publications

  • Cryer, NC and Gush, MB (2025) Landscape water models for irrigation management of green spaces: Integrating landscape crop coefficients, vegetation maps, and water use estimations from soil moisture. Acta Horticulture III International Symposium on Greener Cities: Improving Ecosystem Services in a Climate-Changing World (In Press) 
  • Cryer, NC, Manning, J, Mealey, P, and Gush, MB (2025) Validation of rainwater harvesting efficiency for irrigation of a heritage landscape. Acta Horticulture III International Symposium on Greener Cities: Improving Ecosystem Services in a Climate-Changing World (In Press). 
  • Gush, MB, Brady, L, Pye, J, Manning, J and Cryer, NC (2025) Assessment of the effectiveness of a Sustainable Drainage System (SuDS) applied to a large public car park, through rainfall / runoff monitoring and water balance estimation. Acta Horticulture III International Symposium on Greener Cities: Improving Ecosystem Services in a Climate-Changing World (In Press). 

View all publications prior to joining the RHS here.

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.