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Dahlia
Final Trials Report
2013
Trials Office The Royal Horticultural Society Garden, Wisley, Woking, Surrey, GU23 6QB
Final Report for Trial No. 1979 – Dahlia 2013 1
RHS Trial of Dahlia
Introduction to Dahlia There are 30 species of Dahlia and they originate from Central and South America. The flowers look wonderful in mixed borders in late summer and autumn and make stunning cut flowers. The shorter cultivars also make excellent patio container plants. The dahlia is a very accommodating plant that will grow well in most types of soil. The plants perform best in full sun and prefer moist but well-drained soil. They also benefit from organic matter and a general fertiliser being added to the soil. Deadheading encourages a succession of flowers through the season. Objectives The objectives of the trial were:
To assess plants for the Award of Garden Merit
To assess, compare and demonstrate a range of cultivars, in the open ground, submitted by professional and amateur growers.
Judging Members of the Dahlia Trials Assessment Forum inspected the trial at Wisley on 22nd August; 5th and 19th September and 3rd October. The Trials Assessment Panel considered the plants using the following criteria:
Continuous flowering (5 points)
Disease resistance (5 points)
Earliness (5 points)
Quality of bloom (5 points)
Vigour (5 points)
Foliage (5 points)
Patio container trial 24th September 2013
Final Report for Trial No. 1979 – Dahlia 2013 2
Entries
There were 72 cultivars planted in the open ground, and 31 entries in patio containers in this trial of dahlias. New entries were submitted as rooted cuttings and other entries were propagated from tubers retained from the 2012 trial. Entries were submitted by breeders, nurseries and individuals in the UK and Europe.
Cultivation Soil samples were taken on 24 April 2013 for analysis. The following fertilisers were then applied on 27th May 2013 in preparation for planting: • Ammonium sulphate (for nitrogen) at 20g/m2 • Sulphate of potash (for potassium) 60g/m2 for the 18m section where the Purple and White Sprouting Broccoli trial was previously planted (at the Pavilion end of the bed) & 40g/m2 for the other 44m of the bed. • Kieserite (for magnesium) at 60g/m2 No additional fertiliser was required for phosphorus.
The pH of the soil was considered to be correct at 7.3 (where the Purple and White Sprouting Broccoli trial had been) / 7.4 (other part of the bed). The trial was planted on: • 12th June 2013 into the open ground • 18th June into patio containers which were put out onto the Trials Field on 1st July Dahlias need regular watering to obtain the best results and all of the plants had the benefit of a drip irrigation system. The entries were watered on planting and continued to be watered and fed with a liquid feed as necessary through the season. Pest and Disease The following sprays were used on the trial when necessary: Aphox (active ingredient pirimicarb), insecticide for aphids; SWITCH (active ingredients cyprodinil/ fludioxonil), preventative fungicide for mildew; Systhane (active ingredient myclobutanil), preventative fungicide for mildew; Garshield (preventative anti-fungal and growth stimulant, active ingredients garlic/citrus/seaweed); Spruzit (active ingredient pyrethrin), insecticide for thrips. Other Findings Although no disbudding took place this year, it was noted that disbudding can often improve the flowering display with a number of the Dahlia classifications.
Plants Receiving AGMs During Trial
The following are the plants thought to fulfil the Award of Garden Merit criteria during the trial and to be worthy of receiving the award. The criteria which a plant needs to fulfil in order to receive the award are:
excellent for ordinary use in appropriate conditions
available
of good constitution
essentially stable in form and colour
reasonably resistant to pests and diseases
Final Report for Trial No. 1979 – Dahlia 2013 3
Hardiness ratings are as follows:
H3: Hardy outside in some regions or particular situations or which, while usually grown outside in summer, needs frost-free protection in winter (e.g. dahlias) Dahlia 'Westerton Folly' AGM (H3) 2013 Registered 2013, Classification: Ball Votes: 7-0 [Trial no. 34 - grown in the open ground] Raised by: G Hodgson Sent to trial by: Halls of Heddon Available from: Halls of Heddon Forum member comments: Was excellent all through the season. Flowers look lovely when they are just opening as well as fully open. Nice healthy foliage. Flowers sit nicely at the top of the plant above the foliage. Strong flower stems. Flowers glow in overcast light. Absolutely outstanding. Beautiful. Description (completed in 2013): Height (cm): 170. Habit: Robust plant, upright with lots of flowers, busy. Foliage colour: Green, N137D, greyer green 191B beneath. Leaf features: Glabrous except for scabrid edges, main vein tinges red at base. Stem colour, pubescence, etc.: Green blotchedly blushed with greyish-red, slightly pruneous. Flower size L x W(diameter) (cm): 7 x 9. Colour Petal: Bluish-pink, N74C, darker bluish-purple centre, N80B.
Dahlia 'Chat Noir' AGM (H3) 2013 Registered 1985, Classification: Semi-Cactus Votes: 6-0 [Trial no. 47 - grown in the open ground] Raised by: Ernest Turc Productions SAS Sent to trial by: Rose Cottage Plants Widely available Forum member comments: An excellent garden dahlia. Nice dark stems. Lovely and fresh. Strong, tall stems. Stood up to the bad weather fantastically well. Very consistent. Love the green touch to the centre of the flowers. Description (completed in 2012): Height (cm): 170. Habit: Floriferous, upright. Foliage colour: Green, a bit yellower than 137A. Leaf features: Edges lightly scabrid, sparsely hairy beneath, very short hairs above. Stem colour, pubescence, etc.: Reddish-brown, partly light green, glabrous. Flower size L x W(diameter) (cm): 4 x 15. Colour Petal: Inner ray florets velvety dark Greyed-Purple 187A, outer rays lighter Greyed-Purple 187B-D flushed red-Purple 59A, mix of bright Red-Purple 61A/B and 72A/B on reverse.
Final Report for Trial No. 1979 – Dahlia 2013 4
Dahlia 'Hillcrest Candy' AGM (H3) 2013 Registered 2010, Classification: Semi-Cactus Votes: 6-1 [Trial no. 48 - grown in the open ground] Raised by: L Jackson Sent to trial by: T Bratcher Widely available Forum member comments: An excellent dahlia. Beautiful flower colour. Very easy to grow. Lovely, striking flowers. An eye-catcher. Nice pale centres to flowers. A good garden plant and very floriferous. Description: to be completed in 2014
Final Report for Trial No. 1979 – Dahlia 2013 5
Dahlia 'Karma Choc' AGM (H3) 2013 Registered 2007, Classification: Decorative Votes: 6-1 [Trial no. 72 - grown in the open ground] Raised by: Verwer-Dahlias B.V. Sent to trial by: Verwer-Dahlias B.V. Widely available Forum member comments: Gorgeous dark foliage compliments the flower colour well. Holds its flower colour really well. Strong stems. A good balance of flowers to foliage. Fantastic, amazing. Very fresh looking. Lots of flowers. Very healthy. Description (completed in 2011): Height (cm): 130. Habit: Upright and dark. Foliage colour: Dark Green 147A over flushed with black. Leaf features: Glabrous, patchily strigulose edges, lightly shiny. Stem colour, pubescence, etc.: Purplish Red 187A, glaucous and glabrous. Flower size L x W(diameter) (cm): 8 x 12 . Colour Petal: Very dark Crimson, brighter than 187A-B.
Dahlia 'Twyning's Revel' AGM (H3) 2013 Registered 2012, Classification: Single-flowered Votes: 6-0 [Trial no. 91 - grown in the open ground] Raised by: M Twyning Sent to trial by: National Dahlia Collection Available from: National Dahlia Collection Forum member comments: Unusual flower colour. Love the lilac colour on the back of the petals, it looks fluorescent. Fantastic. Lovely dark foliage. Has flowers all the way up the plant. Description (completed in 2012): Height (cm): 120. Habit: Upright, floriferous. Foliage colour: Green 137A heavily flushed with Greyed-Purple N186A. Leaf features: Edges scabrid, very few hairs on veins above and beneath. Stem colour, pubescence, etc.: Greyed-Purple N186B/C, glaucescent. Flower size L x W (diameter) (cm): 1.5 x 10. Colour Petal: Rays Red 52A heavily flushed with 50A and N74A-C at the tips, base Yellow 12A.
Final Report for Trial No. 1979 – Dahlia 2013 6
Dahlia 'Maiko Girl' AGM (H3) 2013 Registered 2009, Classification: Double Orchid Votes: 7-0 [Trial no. 96 - grown in the open ground] Raised by: K Stock Sent to trial by: K Stock Available from: Aylett Nurseries Ltd Forum member comments: Has been amazing every year. Very floriferous. Always covered in flowers. A neat habit. Neat, tidy flowers. Beautiful flowers. Nice flower form. Strong, healthy plants. Description (completed in 2012): Height (cm): 100. Habit: Upright, floriferous. Foliage colour: Mid Green 137A. Leaf features: Soft textured, very lightly strigulose edges. Stem colour, pubescence, etc.: Pale green, glaucescent. Flower size L x W(diameter) (cm): 3 x 13. Colour Petal: Rays powdery White N155D/C, tips flushed Red-Purple N74C/D.
Final Report for Trial No. 1979 – Dahlia 2013 7
The following entry has been recommended for the AGM but cannot receive the award until it has been registered and / or is available. It is the responsibility of the sender to inform the Trials Office at Wisley that all queries have been resolved.
Dahlia 'Oakwood Naranga' AGM (H3) 2013 Subject to Availability Registered 2010, Classification: Decorative Votes: 7-0 [Trial no. 77 - grown in the open ground] Raised by: S Silver Sent to trial by: S Silver Forum member comments: Healthy plants. A mass of flowers. Flower colour doesn’t fade. Even blooms, nicely spaced. Lovely flower form. Nice strong, dark colour stems. Good strong stems. Clean foliage. Lovely foliage and flower colour combination. Description (completed in 2012): Height (cm): 130. Habit: Very strong, upright, moderately floriferous. Foliage colour: Mid Green, a bit darker than 137A. Leaf features: Slightly strigulose edges. Stem colour, pubescence, etc.: Grey-Purple N186A, partly green at the internodes, glabrous, waxy film. Flower size L x W(diameter) (cm): 6 x 10. Colour Petal: Ray petals ranging from Orange-Red 31A to Yellow-Orange 21C at tips and outer petals, young ray petals close to the disc Orange-Red 34A to 34B.
Final Report for Trial No. 1979 – Dahlia 2013 8
Trial Index and Senders Details N.B Names that are struck through have been checked by RHS Botanists / corrected during the trial.
Container Entries
Planting number
Cultivar and sender Raiser Awards
1 Fifteen Love 'Dream Seeker'
New World Plants via Wyevale Nurseries
K Hammett
2 'Starsister Red-yellow' (Starsister Series) Gootjes-Allplant bv.
Hemgenetics
3 'Starsister Burgundy White' (Starsister Series) Gootjes-Allplant bv.
Hemgenetics
4 Happy Days Cream-White
'Hdw79' (Happy Days Series) Syngenta Floripro Services
Verwer-Dahlias B.V.
5 'Mayo' Green Works Int B.V.
Green Works Int B.V.
6 'Durango' Green Works Int B.V.
Green Works Int B.V.
7 'Hidalgo' Green Works Int B.V.
Green Works Int B.V.
8 'Gallery Rivera' Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
9 Happy Days Red Flame 'Hdrf155' (Happy Days Series) Syngenta Floripro Services
Verwer-Dahlias B.V.
10 'Alamos' Green Works Int B.V.
Green Works Int B.V.
11 'Taxco' Green Works Int B.V.
Green Works Int B.V.
12 'Pink Magic' HM Weijers
HM Weijers
13 Happy Days Pink 'Hdpi117' (Happy Days Series) Syngenta Floripro Services
Verwer-Dahlias B.V.
14 'Chiapas' Green Works Int B.V.
Green Works Int B.V.
15 Happy Days Purple 'Hdpu165' (Happy Days Series) Syngenta Floripro Services
Verwer-Dahlias B.V.
16 'Magenta Magenta' Aylett Nurseries
K Stock
17 'Ruby Murray' K Stock
K Stock AGM (H3) 2012
18 'Veracruz' Green Works Int B.V.
Green Works Int B.V.
19 'Petite Harvest' J R Gott
J R Gott
Final Report for Trial No. 1979 – Dahlia 2013 9
Planting number
Cultivar and sender Raiser Awards
20
Star Wars 'VD TG14'
(Dark Angel Series) Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
21 'My-nute Blend' The Late Mr D Walker
D Walker
22 'Starsister Crimson Splash' (Starsister Series) Gootjes-Allplant bv.
Hemgenetics
23 'Knockout' Plantipp B.V.
K Hammett AGM (H3) 2011
24 Dragon Ball = 'VDTG31' (Dark Angel Series) Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
25 Pulp Fiction = 'VDTG61' (Dark Angel Series) Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
26 American Pie = 'VDTG26' (Dark Angel Series) Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
27 Pretty Woman = 'VDTG43' (Dark Angel Series) Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
28 'Starry Eyes - Red' Rose Cottage Plants
29 'Starry Eyes - Pink' 'Starry Eyes - Red' Rose Cottage Plants
30 'Starsister Orange Stripes' (Starsister Series) Gootjes-Allplant bv.
Hemgenetics
31 'Starsister Crimson Stripes' (Starsister Series) Gootjes-Allplant bv.
Hemgenetics
Sender Details for the Container Entries Allplant, Witte Paal 6, Schagen, 1742 NV Schagen, The Netherlands
Aylett Nurseries Ltd, North Orbital Road, St Albans, Herts, AL2 1DH
Mr J R Gott, 22 Summerville Road, Milnthorpe, Cumbria, LA7 7DF
Green Works International B.V., Witte Paal 341, 1741 LE Schagen, Holland, The Netherlands
New World Plants Ltd, Court Farm, Mansell Gamage, Herefordshire, HR4 7LE
Plantipp BV, Brunel 21, 3401 LJ IJsselstein, Netherlands
Rose Cottage Plants, Bay Tree Farm, Epping Green, Essex, CM16 6PU
Mr K E Stock, c/o Trials Office.
Syngenta FloriPro Services, CPC4 Cappital Park, Fulbourn, Cambridge, CB21 5XE
The Late Mr D Walker c/o Trials Office
Final Report for Trial No. 1979 – Dahlia 2013 10
Mr HM Weijers, Herenweg 302e, Noordwijkerhout, The Netherlands, 2211 VE
Verwer-Dahlias B.V., Fa Gebr Verwer, 3e Poellaan 73/75, 21 61 DL, Lisse, Netherlands
Plants in the open ground Planting number
Cultivar and sender Raiser Awards
Anemone flowered
32 'The Phantom' Rose Cottage Plants
Small Ball
33 'Camelia' Geerlings Dahlias
Geerlings
34 'Westerton Folly' Halls of Heddon
G Hodgson AGM (H3) 2013
35 'Jodie Wilkinson' R Pearce
L Jones
Miniature Ball
36 'Tahoma Lady Oh' D Kent
L Connell
37 'Marston George' D Kent
J Digweed
38 'Oakwood Natasha' S Silver
S Silver
Medium Cactus
39 'Oakwood Bridesmaid' S Silver
S Silver
Small Cactus
40 'Gryson's Yellow Spider' Geerlings Dahlias
W Gryson
Giant Semi-Cactus
41 'Coral Jupiter' Ridgeview Nursery
Not known
Large Semi-Cactus
42 'Susan Carey' D McMaster
D McMaster AGM (H3) 2011
43 'Trooper Dan' Halls of Heddon
R & D Parshall
44 'Oakwood Lyndon S' S Silver
S Silver
Medium Semi-Cactus
45 'Hillcrest Jessica J' Ridgeview Nursery
L Jackson
46 'Clearview Louise' D Kent
R & D Parshall
47 'Chat Noir' Rose Cottage Plants
Ernest Turc Productions SAS
AGM (H3) 2013
48 'Hillcrest Candy' T Bratcher
L Jackson AGM (H3) 2013
Final Report for Trial No. 1979 – Dahlia 2013 11
Planting number
Cultivar and sender Raiser Awards
Small Semi-Cactus
49 'Delphine' V Wakefield
Unknown
50 'Melody Gipsy' Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
51 'Ruskin Andrea' Ridgeview Nursery
S Pennington
52 'Oakwood Firelight' S Silver
S Silver
Miniature Semi-Cactus
53 'Tom McLelland' M J Roberts
54 'Val's Candy' F Taylor
P J Oram
Fimbriated
55 'Fleurel' Rose Cottage Plants
C W M van den Lans de Boer
56 'Jean Ellen' R Marks
P Godsmark
Collerette
57 'Susan Gilbert' Halls of Heddon
58 'Hootenanny' Halls of Heddon
59 'Esther Chamberlain' I Kitchener via J Gott
I Kitchener
Giant Decorative
60 'Café au Lait' National Dahlia Collection
Bruidegom
61 Croydon Jumbo' National Dahlia Collection
Brand
62 'Black Monarch' National Dahlia Collection
C F Pape
63 'Jocondo' 'Elma E Elizabeth' National Dahlia Collection
Bruidegom
64 'Blood Orange' D McMaster via J Jack
D McMaster
65 'Sir Alf Ramsay' National Dahlia Collection
L P Cleaver
Large Decorative
66 'Otto's Thrill' Rose Cottage Plants
Aumiller
67 'Vassio Meggos' Geerlings
S Meggos
68 'Emory Paul' Great Dixter
Baynes
69 'Mom's Special' Rose Cottage Plants
L Connell
Final Report for Trial No. 1979 – Dahlia 2013 12
Planting number
Cultivar and sender Raiser Awards
70 'John Hill' Halls of Heddon
I Hill
71 'Westerton Lillian' Halls of Heddon
G Hodgson
Small Decorative
72 'Karma Choc' Verwer-Dahlias B.V.
Verwer-Dahlias B.V. AGM (H3) 2013
73 'Karma Fiesta' Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
74 'Ocean Bird' F vd Vlugt
van der Vlugt & N Kops
75 'Oakwood Marian S' S Silver
S Silver
76 'Maldiva' Rose Cottage Plants
Miniature Decorative
77 'Oakwood Naranga' S Silver
S Silver AGM (H3) 2013
Subject to availability
78 'La Recoleta' Rose Cottage Plants
Nuland
79 'Barbarry Sultan' D Kent
B Davies
Waterlily
80 'Edwin's Sunset' F Taylor
B Woodford
81 'Kilburn Rose' G Hill
G Hill
82 'FirePot' Rose Cottage Plants
Miscellaneous
83 'Classic Swanlake' Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
84 'Classic Poème' Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
85 'Tally Ho Double' Bridgemere Nurseries INTEREST ONLY
Bridgemere Nurseries
N/A 'Tally Ho Double' Bridgemere Nurseries INTEREST ONLY
Bridgemere Nurseries
N/A
'My-nute Blend' The Late Mr D Walker INTEREST ONLY – Growing in the container section of the trial
D Walker
86 'Purple Haze' Rose Cottage Plants
E van Dangen
87 'Classic Rosamunde' Verwer-Dahlias B.V.
Verwer-Dahlias B.V.
Final Report for Trial No. 1979 – Dahlia 2013 13
Planting number
Cultivar and sender Raiser Awards
88 'Waltzing Mathilda’ Rose Cottage Plants
Ru-Ro Plant
Single flowered
89 'Hadrian's Sunlight' Halls of Heddon
90 Magenta Star' J Wheatley
K Hammett AGM (H3) 2008
91 'Twyning's Revel' National Dahlia Collection
M Twyning AGM (H3) 2013
92 'Bright Eyes' Rose Cottage Plants
G Preijde
Single Orchid
93 'Trelyn Gwenda' R Tudor
R Tudor
94 'Honka Fragile' Rose Cottage Plants
Dutch origin
Double Orchid
95 'Hey Pedro!' Aylett Nurseries
Ken Stock
96 'Maiko Girl' K Stock
K Stock AGM (H3) 2013
Stellar
97 'AC Golden Nickel' RHS Garden Wisley
K Greenway
98 'AC Rooster' RHS Garden Wisley
K Greenway
99 'Snoho Monika' RHS Garden Wisley
GW & I Boneywell
100 'Clearview Erin' RHS Garden Wisley
R & D Parshall
101 'Irish Pinwheel' 'Irish Speckles' RHS Garden Wisley
S & S Boley
102 'Bloomquist Pumpkin' RHS Garden Wisley
P Bloomquist
103 'Verrone's Taylor Swift' RHS Garden Wisley
R Verrone
Sender Details for the Open Ground Entries
Aylett Nurseries Ltd, North Orbital Road, St Albans, Herts, AL2 1DH
Mr T Bratcher, c/o Trials Office
Chiltern Flowers, c/o Trials Office
Firma vd Vingt, Fredereikslaan 7, Hillegom, The Netherlands, 2182 DD
Mr J Geerlings, Geerlings Dahlias, Kadijk 38, 2104AA Heemstede, The Netherlands
Mr J R Gott, 22 Summerville Road, Milnthorpe, Cumbria, LA7 7DF
Halls of Heddon, West Heddon Nursery, Heddon-on-the-Wall, Northumberland, NE15 0JS
Great Dixter House & Gardens, Great Dixter, Northiam, Nr Rye, East Sussex, TN31 6PH
Final Report for Trial No. 1979 – Dahlia 2013 14
Mr G Hill, Lisa's Cottage, Kilburn Road, Coxwold, York, YO61 4AF
Mr J Jack, c/o Trials Office
Mr D Kent, 48 Vickers Road, Ash Vale, Hampshire, GU12 5SE
Dr D McMaster, 20 Cabra Road, Hillsborough, Co Down, BT26 6NB
National Dahlia Collection, Varfell Farm, Long Rock, Penzance, Cornwall, TR20 8AQ
New World Plants Ltd, Court Farm, Mansell Gamage, Herefordshire, HR4 7LE
Mr R Pearce, c/o Trials Office
Ms I Cruickshanks, Ridgeview Nursery, Crossroads by Longridge, West Lothian, EH47 9AB
Mr M Roberts, 73 Castle Road, Weddington, Nuneaton, Warwickshire, CV10 0EW
Rose Cottage Plants, Bay Tree Farm, Epping Green, Essex, CM16 6PU
Mr S Silver, 'Oakwood', 29 Thornhill, Chacombe, Banbury, Oxfordshire, OX17 2JG
Mr F B Taylor, Taylor's Dahlias, 3 Willow Drive, Sale, Cheshire, M33 4NN
Mr R Tudor, 34 Victoria Road, Fleur de lys, Blackwood, Gwent NP12 3UG
The Late Mr D Walker, c/o Trials Office
Mr J Wheatley, Stonebarn, Moorledge Farm, Chew Magna, Bristol, Avon BS40 8TL
Verwer-Dahlias B.V., Fa Gebr Verwer, 3e Poellaan 73/75, 21 61 DL, Lisse, Netherlands
Mrs V Wakefield, Bramdean House, Bramdean, Nr Alresford, Hampshire, SO24 0JU
Plant Trials Bulletin on Dahlias
A colour trials bulletin was published in 2009 entitled “Open-centred Dahlias and can be downloaded from the RHS website using the following link www.rhs.org.uk/Plants/RHS-Publications/Plant-bulletins/Open-centred-Dahlias
Alternatively if you would like a printed copy please contact: The Trials Office, RHS Garden Wisley, Woking, Surrey GU23 6QB. Please enclose an A4 SAE. They cost £2 per copy (a donation towards costs); cheques to be made out to Royal Horticultural Society.
The whole AGM plant list was reviewed in 2012 and the updated list can be found here: http://www.rhs.org.uk/Plants/Plant-trials-and-awards/Plant-awards/AGM-plants
Final Report for Trial No. 1979 – Dahlia 2013 15
Dahlia Classifications Text Source: Twenty-third Supplement to The Tentative Classified List and International Register of Dahlia Names 1969 (2013). Photographs: RHS Trials
D. 'Moonfire'
Group 1: Single–flowered dahlias
Single outer ring of florets, which may overlap, the centre forming a disc.
D. 'Ryecroft Marge'
Group 2: Anemone–flowered dahlias
One or more outer rings of generally flattened ray florets surrounding a dense group of tubular florets, which are longer than the disc florets in Single dahlias, and showing no disc.
D. 'Don Hill'
Group 3: Collerette dahlias
A single outer ring of generally flat ray florets, which may overlap, with a ring of small florets (the Collar), the centre forming a disc.
D. 'Charlie Dimmock'
Group 4: Waterlily dahlias
Fully double blooms characterised by broad and generally sparse ray florets, which are straight or slightly involute along their length giving the flower a shallow appearance. The depth should be less than half the diameter of the bloom.
D. 'Dikara Midnight'
Group 5: Decorative dahlias
Fully double blooms showing no disc. The ray florets are generally broad and flat and may be involute for no more than 75% of their length (longitudinal axis), or slightly twisted and usually bluntly pointed.
Final Report for Trial No. 1979 – Dahlia 2013 16
D. 'Blyton Softer Gleam'
Group 6: Ball dahlias
Fully double blooms, ball shaped or slightly flattened. The ray florets are blunt or rounded at the tips, with margins spirally arranged and involute for at least 75% of the length of the florets.
D. 'Will's Ringwood Rosie'
Group 7: Pompon dahlias
Fully double, spherical blooms of miniature size, with florets involute for the whole of their length (longitudinal axis).
D. 'Lakeland Sunset'
Group 8: Cactus dahlias
Fully double blooms, the ray florets are usually pointed, the majority narrow and revolute for more than 50% or more of their length (longitudinal axis) and either straight or incurving.
D. 'Julie's Delight'
Group 9: Semi-Cactus dahlias
Fully double blooms, the ray florets are usually pointed, and revolute for more than 25% of their length and less than 50% of their length (longitudinal axis), broad at base and either straight or incurving.
Group 10: Miscellaneous dahlias
Any dahlias which do not fall into one of the listed groups
Final Report for Trial No. 1979 – Dahlia 2013 17
D. 'Anna Cozens'
Group 11: Fimbriated dahlias
Ray florets should be evenly split or notched into two or more divisions, uniformly throughout the bloom to create a fringed overall effect. The petals may be flat, involute, revolute, straight, incurving or twisted.
D. 'Juul's Allstar'
Group 12: Single-Orchid (Star) dahlias
Single outer ring of florets surrounding the disc. Ray florets are uniformly either involute or revolute.
D. 'Mayan Pearl'
Group 13: Double-Orchid dahlias
Fully double blooms, showing no disc, that have triangular centres. Ray florets are narrowly lanceolate and either involute or revolute.
D. 'Bishop of Llandaff'
Group 14: Peony-flowered dahlias
Large flowers consisting of three or four rows of flattened expanded rays somewhat irregularly arranged, and surrounding a golden disc similar to that of the single dahlias.
Dwarf Bedder
The use of “Dw.B” after the classification of a cultivar indicates that it is a dwarf bedding dahlia, not usually exceeding 600mm (24in) in height.
Lilliput dahlias
The use of (Lil.) after the classification of a cultivar indicates that it is a low-growing type of dahlia usually no more than 0.3m (12in) in height having single, semi-double or double florets attaining 26mm (1in) or so in diameter. They are especially suitable for borders or display in containers on patios, etc. Sometimes referred to as "baby" or "top-mix" types of dahlia.
Final Report for Trial No. 1979 – Dahlia 2013 18
Source: Horticultural Trials and Relations, RHS Garden Wisley, Woking, Surrey GU23 6QB
E-mail: [email protected]
More information about RHS Trials and other colour illustrated reports can be found on the RHS Website: http://www.rhs.org.uk/trials