Sharon McDonald

Sharon is responsible for the registration of new conifer, Dahlia, Dianthus and Rhododendron cultivars – ensuring uniformity, accuracy and stability in the naming of cultivated plants

What do you do?

I register 250–300 new cultivars of conifer, Dahlia, Dianthus and Rhododendron every year.
The plant registration process begins when someone, who has a new variety they want to name, contacts me directly or when my work monitoring journals, nursery catalogues and even the RHS Plant Finder looking for previously unrecorded names throws up a mystery cultivar and I contact the breeder to ask if they would like to formally register their variety.
In registering a new variety, I have to ensure the chosen name is acceptable – meaning it doesn’t contravene the International Code of Nomenclature for Cultivated Plants (ICNCP) – before adding the information to the registration database, so that we have the best possible picture of the cultivated plants for these plant groups.

“I’ve always been inquisitive. Learning about science and how the world worked seemed a good way to get answers to some of the questions that I had.”

Why is your team’s research important?

Sometimes a plant can be sold under several different names. It’s my job to find all of those names and connect them, so that when a gardener goes to their local nursery, they can be sure that they are buying the plant they are looking for, regardless of what name it is sold under.
Plant registration can help guide conservation plans. It also gives a brief glimpse into social history, with names providing snapshots of trends in different generations. For example, most plant groups will have the name ‘Waterloo’ as well as the names of well-known politicians or celebrities.

Projects I’m working on now

  • Compiling the new International Dahlia Register and Checklist (2022)
  • Working on supplements to the current Registers of DahliaDianthus and Rhododendron and a list of conifer registrations from 2013–20

Completed projects

  • In 2018 we completed the online Dahlia registration form, which enables people to register their new cultivars online, quickly and easily, rather than filling in hard copy forms


Since 2008 we’ve added more than 30,000 new plant records to the dahlia registration database, combined with the dahlia register and its supplements – which themselves account for around 19,000 records. We now have more than 63,000 Dahlia records.


  • McDonald S. (2019) The International Dahlia Register (1969). 28th Supplement, Royal Horticultural Society, London
  • McDonald S. (2019) The International Rhododendron Register and Checklist (2004). 14th Supplement, Royal Horticultural Society, London
  • Brickell CD (ed.) (2016) A-Z Encyclopedia of Garden Plants. Fourth edition. Dorling Kindersley, London (as a contributor)
  • McDonald S. (2014) Additions to the International Conifer Register 2008–12. Conifer Quarterly, 31 (2), pp30–39
  • McDonald S, Hedge RW. (2008–18) The International Dahlia Register (1969). 19th Supplement to 27th Supplement, The Royal Horticultural Society, London
  • McDonald S. (2008–13) The International Daffodil Register and Classified List (2008). First Supplement to Sixth Supplement, The Royal Horticultural Society, London
  • McDonald S. (2007) The International Daffodil Register and Classified List (1998).Tenth Supplement, The Royal Horticultural Society, London

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.