Argyranthemum Final Trials Report 2011 Trials Office The Royal Horticultural Society Garden, Wisley, Woking, Surrey, GU23 6QB Final Report for Trial Ref 1899 1 RHS Trial of Argyranthemum Introduction to Argyranthemum Argyranthemum, Greek for ‘silver flower’ is a genus of around 37 species found naturally in the Canary Islands and Madeira archipelagos. They are very closely resemble Chrysanthemum, but differ having daisy like flowers; a shrubby habit and are evergreen. Although Argyranthemum can be grown outdoors, most are too tender all year round in the UK, These plants are not fully hardy and either requires bringing into a cool greenhouse or being treated as an annual used as part of a bedding schemes, in containers or in borders. They have a long flowering period, usually May through to October or the first frost. The foliage is finely dissected or lobe and can have a bluish green. The daisy-like flowers are borne in loose corymbs and vary from single, anemone-centred, or double. Colours are available in a wide range from white, yellow, pink to apricots. Objectives The objectives of the trial were: To compare new breeding to old AGM varieties. Record flowering period and eliminate short day flowering varieties. Compare habit and compactness. Judging The plants were assessed by the Floral Trials Assessment Panel fortnightly, beginning on 12th July 2011. Judging was based on the following criteria: Floriferousness : Continuity : Habit : Flower Colour : Foliage : How flowers die Entries There were 107 entries in the trial supplied by growers, breeders, individuals and nurseries from the UK and Europe. Each entry consisted of 3 plants, sent as plugs or cuttings and grown on to 1 litre pots by the propagation department before planting. Cultivation Whilst being grown on by propagation, all plants were cut back to stop early flowering and encourage a compact, bushy habit. This was done by shearing to a height of about 20cm. Entry 91, believed to be the true ‘Jamaica Primrose’ did not respond to this treatment. Planting was carried out in June into a rotovated bed with no fertilisers or soil improvers added. Argyranthemum does not need rich soils to thrive. Smaller entries were planted in groups of three in a triangle whilst larger entries were planted in a line. One plant of each entry was deadheaded fortnightly, but plants received no other treatments. Irrigation pipes were laid and used when necessary. Pest and Disease Final Report for Trial Ref 1899 2 No pest problems were encountered. A number of entries showed signs of Chlorosis e.g. entry 77 – tests for chrysanthemum yellow virus were not conclusive. Other Findings During the trial it was noted that all plants were substantially larger than those grown in the natural conditions. The panel agreed that the high levels of nitrogen in the soil (the trial bed had previously been used to grow winter squash) cause plants to have greener foliage than is normal in those varieties with blue (glaucous) leaves and stems were not as strong causing some entries to collapse or for stems to snap. The panel took particular interest during the assessment of the need to ‘Deadheading’ each cultivar. There were a number of plants where the visual impression was a marked improvement whilst others no benefit was obvious for what was recognised as a tedious job. 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 garden use available from nurseries reasonably resistant to pests and diseases of good constitution essentially stable in form and colour reasonably easy to grow Hardiness ratings are as follows: H3 – hardy outside in some regions; needs frost-free protection in winter H4 – hardy throughout the British Isles Final Report for Trial Ref 1899 3 Plants Awarded AGM Argyranthemum LaRita White Beauty = ‘Kleaf07028’ PBR (LaRita Series) [Trial No.32] votes 7-2 Habit: Spreading mound, moderately floriferous Height x spread: (cm): 60 x 80 Foliage colour: Mid Green 137B with glaucous overtones Leaf pubescence and features: Dull and glabrous, glaucous Stem colour, pubescence, etc.: Green and glaucous, glabrous Flower diameter: (mm) 40 Flower colour: Rays White NN155D, disk Yellow 13A, florets opening white with yellow tips.” “Deadhead to get best display” Comments “Clear, blue green foliage. Neat flowers. Solid white. Sender: Selecta Klemm GmbH & Co KG Figure 1: Deadheaded Figure 2: Not Deadheaded Argyranthemum Molimba XL Duplo White = 'Argydowitis' (Molimba Series) Final Report for Trial Ref 1899 4 [Trial No.33] votes 11-0 Habit: Spreading mound, moderately floriferous Height x spread: (cm): 60 x 80 Foliage colour: Mid Green 137B with glaucous overtones Leaf pubescence and features: Dull and glabrous, glaucous Stem colour, pubescence, etc.: Green and glaucous, glabrous Flower diameter: (mm) 40 Flower colour: Rays White NN155D, disk Yellow 13A, florets opening white with yellow tips Comments “Spectacular.” Sender: Syngenta Seeds Argyranthemum frutescens LaRita Banana Split Final Report for Trial Ref 1899 5 [Trial No.36] votes 10-0 Habit: Moderately floriferous, slightly spreading mound Height x spread: (cm): 40 x 50 Foliage colour: Mid Green 137B Leaf pubescence and features: Glabrous Stem colour, pubescence, etc.: Mostly glabrous, one or two hairs on new growth, green, light dull red flush in axils and side shoots Flower diameter: (mm) 50 Flower colour: Rays pale Yellow 4D, mottled Purplish Red 60B/C about edges and tip, disk Reddish Brown, browner than N34A, opening Yellow 15B Comments “Different. Beautiful. Domed shape. Original” Sender: Selecta Klemm GmbH & Co KG Final Report for Trial Ref 1899 6 Argyranthemum Sultan’s Lemon = ‘Supalem’ PBR [Trial No.38] votes 7-1 Habit: Description to be completed in 2012. Comments “Pretty, finely divided foliage Compact bushes. Dead flowers hidden well.” Sender: PLA International ApS Argyranthemum ‘Summer Stars’ (Daisy Crazy Series) Final Report for Trial Ref 1899 7 [Trial No.58] votes 9-1 Habit: Upright bush, moderately floriferous Height x spread: (cm): 50 x 50 Foliage colour: Mid Green 137A Leaf pubescence and features: Glabrous, glaucous, moderately thick. Stem colour, pubescence, etc.: Glabrous, pale green, striate and glaucous. Flower diameter: (mm) 50 Flower colour: Pale Pink 69C flushed Purplish Pink72D especially on outer rays. Comments: Comments “Impressive display, good covering of bloom. Upright.” Sender: Mr A J Robinson Figure 3: Deadheaded Figure 4: Not Deadheaded Argyranthemum Cherry Love = ‘Supacher’ PBR (Daisy Crazy Series) Final Report for Trial Ref 1899 8 [Trial No.59] votes 10-2 Habit: Spreading mound, floriferous Height x spread: (cm): 65 x 100 Foliage colour: Blue Green, bit darker than N138A Leaf pubescence and features: Glabrous, glaucous, moderately thick. Stem colour, pubescence, etc.: Green, flushed dull Red Grey N187B, darker in places especially axils and striations on pedicel Flower diameter: (mm) 45 Flower colour: Rays Red Purple 64B fading to pale Purple N74D on older flowers, disk Red 60A opening to a mix of petaloid florets the same colour as rays and tubular florets ranging from 64B to pale Pink 62D Comments “Very pretty foliage. Nice contrast in flowers and foliage. Good overall effect.” Sender: Mr A J Robinson Figure 5: Deadheaded Figure 6: Not Deadheaded Argyranthemum frutescens Madeira Cherry Red = ‘Bodmadcher’ PBR (Madeira Series) [Trial No.62] votes 11-0 Final Report for Trial Ref 1899 9 Habit: Spreading mound, moderately floriferous Height x spread: (cm): 45 x 70 Foliage colour: Mid Green 137B Leaf pubescence and features: Glabrous, moderately thick. Stem colour, pubescence, etc.: Green, dull red flush in axils, fine dark Brown N200A striations on pedicels, glabrous Flower diameter: (mm) 30 Flower colour: Rays bright Red 53A with white base, ageing to a much duller Purple N84D, disk Orange Red N34A with darker brown central dot, opening to Yellow 16A Comments “Really pretty. Consistent. Good performing plant.” Sender: Ball Colegrave Figure 7: Deadheaded Figure 8: Not Deadheaded Argyranthemum Madeira Violet (Madeira Series) [Trial No.64] votes 12-3 Final Report for Trial Ref 1899 10 Habit: Upright, very floriferous bush Height x spread: (cm): 70 x 80 Foliage colour: Young leaves Yellow Green 146C, older leaves Mid Green 137A Leaf pubescence and features: Glabrous Stem colour, pubescence, etc.: Green, lightly glaucescent, glabrous Flower diameter: (mm) 45 Flower colour: Rays dark Purplish Red 71A/B finely dotted and streaked white, wholly white at base, disk Orange Brown 175B-C opening Yellow 13A-B Comments “Looks great! Lots of blooms; Good Late Pink; Dead Flowers hidden well.” Sender: Ball Colegrave Figure 9: Deadheaded Figure 10: Not Deadheaded Argyranthemum Meteor Red (Daisy Crazy Series) [Trial No.66] votes 12-1 Final Report for Trial Ref 1899 11 Habit: Spreading mound, moderately floriferous Height x spread: (cm): 50 x 70 Foliage colour: Yellow Green, greener than 146A Leaf pubescence and features: Glabrous Stem colour, pubescence, etc.: Green with fine, darker green striations, glabrous Flower diameter: (mm) 40 Flower colour: Rays bright, rich Red, brighter and redder than 59A, dulling down slightly in older flowers, disk Red Brown 178B opening to Yellow 12A Comments “Rich colour when flowers are young. Flower suits foliage. Cleanest of reds” Sender: R Delamore Ltd Figure 11: