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Plant trials and awards

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The RHS seal of approval

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If you have ever visited a garden centre or nursery, you will probably have seen the result of the RHS trials.

A cup symbol on a plant’s label shows that it has earned the RHS Award of Garden Merit (AGM) – the RHS seal of approval that the plant performs reliably in the garden.

Lauched in February 2011, the RHS AGM logo (above) appears on plant labels and displays in the nation's garden centres. 

Vinca on trial

Vinca minor La Grave

The RHS trial of Vinca started in 2011 and continued into 2013. Grow periwinkles such as Vinca minor 'La Grave' AGM (above) in any aspect and enjoy the pretty, propeller-shaped flowers.

10 AGM plants for...

Camellia sasanqua ‘Narumigata’

Each month Graham Rice picks out 10 of the best AGM plants.

This month: the best winter-interest climbers and wall shrubs, including Camellia sasanqua 'Narumigata' (above).

Latest AGM plants

ruby chard Bali

Plantsman Graham Rice picks out top plants that have won an Award of Garden Merit (AGM). Rhubarb chard 'Bali' is impressive, attractive and reliable.

RHS trial results

Search the trial database

Search our trial database for results from the 1920s onwards.

Yearly trials

2010 trials

Daffodils on trial

Stipa calamagrostis

Plan your visit to the Narcissus trial at RHS Garden Wisley this spring.

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Buy AGM plants

Lonicera x purpusii Winter Beauty

Did you know that you can buy AGM plants online from the RHS?

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New plants

New plants

Well-respected plantsman, Graham Rice, uncovers all the latest new plants in his blog.

RHS plant bulletins

RHS plant bulletins

The results of many of our major trials are now being produced in full colour plant bulletins.