National Collection Holders have a statutory exemption from water use restrictions, such as hosepipe bans, for watering the plants in their collections.
This exemption recognises the important role of National Collections in conserving special plants for the future. However, like all of us, National Collection holders are encouraged to use water efficiently and to minimise use of tap water during peak periods (morning and evening).
The legal position
The exemption for National Plant Collections is contained in the Water Use Order 2010, Article 6 part (b)ii. This states that the water use restriction does not include watering plants on domestic or other non-commercial premises using a hosepipe if they are grown or kept for sale or commercial use or "...that are part of a National Plant Collection or temporary garden or flower display." It defines plants to to include plant organs, seeds, crops and trees.
Water companies should be aware of this exemption (e.g. South East water list it on their website here and Thames Water also list it). We are contacting other water companies and have asked the Environment Agency to make them aware. If your water company does not accept your exemption, we can provide a letter confirming this. Please note the exemption does not apply to watering other plants in a collection holder's garden, only the National Collection plants.
The Environment Agency website has more information and advice about temporary usage bans. The government provides guidance to water companies on managing water in droughts (see for example the 2025 guidance here).
Water efficiency
Due to climate change, we will experience more extreme weather including floods and droughts, which makes it all the more important to manage water efficiently.
We know that many National Collection holders already apply sustainable water practices, including collecting and storing rainwater, and drip feed irrigation systems. We are keen to share best practice through our website, workshops and talks - if you have examples to share, please get in touch. The RHS website has lots of general advice on ways to save water in the garden.
RHS guidance on water efficiency
Our National Collection holder bursary can be used to help fund investments that support your collection, including more sustainable practices, and we are applying for grants so we can increase the amount of support available. The bursary web page also gives details of other funding sources.
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