Delphinium (from seed) trial 2023–2025

Objectives and purpose of the trial

The focus of this trial is on Delphinium that you can buy and grow from seeds, with the aim of growing new seed strains alongside existing AGM selections. The last time delphiniums from seeds were trialled by the RHS was in 2008, and many new introductions have since been developed. Some of these introductions have been grown for the cut-flower industry, and this will be a chance to see how these plants perform in gardens at RHS Wisley, Surrey. Those that perform well will be awarded the RHS Award of Garden Merit (AGM).

Delphinium on display in the Trial Garden at RHS Wisley

Rows of colourful delphiniums come to life in summer

Judges and criteria

Judging criteria

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

• Germination
• Vigour
• Flower quality and form

• Flower impact and colour
• Leaf quality
• How well the plants come back each year

Suppliers to the trial

• Ball Colegrave
• Chiltern Seeds
• Delphinium Society
• Sakata
• Syngenta
• Miyoshi & Co., Ltd

• Mr Fothergill’s
• New Zealand Delphiniums
• Nicky’s Nursery
• Plants of Distinction
• Unwins Seeds

List of plants in the trial

View all the delphinium seeds on trial at RHS Wisley

• Delphinium (Belladonna Group) ‘Blue Donna’ 
• Delphinium (Belladonna Group) ‘Oriental Blue’ 
• Delphinium elatum ‘Ariel Blue’ 
• Delphinium ‘Black Eyed Angels’ (New Millennium Series) 
• Delphinium Blue Buccaneers Mixed (New Millennium Series) 
• Delphinium ‘Candle Blue Shades’ 
• Delphinium ‘Candle Lavender Shades Improved’ 
• Delphinium ‘Candle Light Blue Shades’ 
• Delphinium ‘Candle Violet Shades’ 
• Delphinium ‘Candle White Shades Improved’ 
• Delphinium ‘Centurion Lilac Blue’ (Centurion Series)   
• Delphinium ‘Centurion Sky Blue’ (Centurion Series) 
• Delphinium ‘Cobalt Dreams’ (New Millennium Series) 
• Delphinium elatum ‘Dasante Blue’ 
• Delphinium elatum ‘Delphina Dark Blue Black Bee’ 
• Delphinium elatum ‘Delphina Dark Blue White Bee’ 
• Delphinium elatum ‘Delphina Light Blue White Bee’ 
• Delphinium elatum ‘Delphina Pink White Bee’ 
• Delphinium elatum ‘Delphina Rose White Bee’ 
• Delphinium elatum ‘Delphina White’ 
• Delphinium Delphinium Society Mixed 
• Delphinium elatum ‘Lilac Ladies’ (New Millennium Series) 
• Delphinium Mini Pinks Mixed (New Millennium Series) 
• Delphinium ‘New Dawn’ (New Millennium Series) 
• Delphinium ‘Pink Blush’ (New Millennium Series) 
• Delphinium elatum ‘Raspberry Rhapsody’ (New Millennium Series) 
• Delphinium ‘Sapphire Jewels’ (New Millennium Series) 
• Delphinium elatum ‘Sweethearts’ (New Millennium Series) 
• Delphinium elatum ‘Triton Dark Blue’ 
• Delphinium ‘Twilight Blues’ (New Millennium Series) 
• Delphinium grandiflorum ‘Blue Butterfly’ 
• Delphinium grandiflorum ‘Cheer Blue’ 
• Delphinium grandiflorum ‘Delfix Blue’ (Delfix Series) 
• Delphinium grandiflorum ‘Delfix White’ (Delfix Series) 
• Delphinium grandiflorum ‘Diamonds Blue’ 
• Delphinium grandiflorum ‘Hunky Dory Blue’ 
• Delphinium grandiflorum ‘Hunky Dory Sky Blue’ 
• Delphinium grandiflorum ‘Hunky Dory White’ 
• Delphinium grandiflorum ‘Morpho Chiffon Blue’ 
• Delphinium grandiflorum ‘Morpho Grand Blue No. 3’ 
• Delphinium grandiflorum ‘Morpho Happy Pink’ 
• Delphinium grandiflorum ‘Morpho Platinum Blue’ 
• Delphinium grandiflorum ‘Morpho Silky White’ 
• Delphinium grandiflorum ‘Pink Butterfly’ 
• Delphinium grandiflorum ‘Planet Blue’ 
• Delphinium grandiflorum ‘Planet Light Pink’ 

Get in touch

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].