Mahonia trial 2023–2025

Objectives and purpose of the trial

The purpose of this trial is to assess Mahonia (Oregon Grape) cultivars grown in open ground. Working in partnership with RHS Partner Garden Sir Harold Hillier Garden, Romsey, to deliver the trial behind the scenes, the RHS Trials team will look to demonstrate cultivation and confirm correct naming and classification. Those that perform best will be awarded the RHS Award of Garden Merit (AGM).
Trial beds with flourishing mahonias at Sir Harold Hiller Gardens
Plant portrait of Mahonia x media ‘Charity’

Judges and criteria

Judging criteria

The following factors are all taken into consideration as part of the judging of the trial:

  • Flower quality
  • Colour and size
  • Length of flowering period
  • Foliage quality

  • Fruiting
  • Growth habit
  • Vigour

List of plants in the trial

View all the mahonias on trial at Sir Harold Hillier Gardens
  • Mahonia × emeiensis ‘Emei Shan’
  • Mahonia × lindsayae ‘Cantab’
  • Mahonia × media ‘Buckland’
  • Mahonia × media ‘Charity’
  • Mahonia × media ‘Charity’s Sister’
  • Mahonia × media ‘Hope’
  • Mahonia × media ‘Hope’s Rival’
  • Mahonia × media ‘Lionel Fortescue’
  • Mahonia × media ‘Marvel’
  • Mahonia × media ‘Rebecca’
  • Mahonia × media ‘Roundwood’
  • Mahonia × media ‘Underway’
  • Mahonia × media ‘Winter Sun’
  • Mahonia × savilliana
  • Mahonia × savilliana ‘Factor’
  • Mahonia × savilliana ‘Roy’s Choice’
  • Mahonia acanthifolia
  • Mahonia ‘Alan Postill’
  • Mahonia ‘Arthur Menzies’
  • Mahonia bealei
  • Mahonia bealei ‘Cornish Silver’
  • Mahonia breviracema
  • Mahonia duclouxiana
  • Mahonia ‘Esme’
  • Mahonia eurybracteata
  • Mahonia eurybracteata [Sweet Winter] (‘Minganpi’)
  • Mahonia eurybracteata ‘Narihira’
  • Mahonia eurybracteata subsp. ganpinensis [Meteor] (‘Hillmah’)
  • Mahonia eurybracteata subsp. ganpinensis ‘Chalingba’
  • Mahonia eurybracteata subsp. ganpinensis ‘Soft Caress’
  • Mahonia fortunei
  • Mahonia fortunei ‘Curlyque’
  • Mahonia gracilipes
  • Mahonia huiliensis
  • Mahonia japonica
  • Mahonia japonica ‘Hivernant’
  • Mahonia ‘Jermyns’
  • Mahonia lancasteri
  • Mahonia leptodonta
  • Mahonia magnifica
  • Mahonia napaulensis ‘Maharajah’
  • Mahonia nitens
  • Mahonia nitens ‘Cabaret’
  • Mahonia oiwakensis
  • Mahonia oiwakensis subsp. lomariifolia ‘Rubrifolia’
  • Mahonia oiwakensis subsp. lomariifolia var. tenuifoliola
  • Mahonia ‘Pan Demic’
  • Mahonia ‘Pan’s Peculiar’
  • Mahonia ‘Postill’s Puzzle’
  • Mahonia sheridaniana
  • Mahonia ‘Silverback’
  • Mahonia ‘Spinetingle’
  • Mahonia ‘Stickleback’
  • Mahonia taronensis
  • Mahonia ‘Winter Bronze’
RHS Award of Garden Merit logo
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For more information on our RHS Plant Trials or to access older trial reports, please get in touch with our team via email at [email protected].

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