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: trials@rhs.org.uk

More information about RHS Trials and other colour illustrated reports can be found on the RHS Website: http://www.rhs.org.uk/trials