CROCUS SPRING FLOWERING Final Trials Report 2006 – 2009 Trials Office The Royal Horticultural Society Garden, Wisley, Woking, Surrey, GU23 6QB Crocus Spring Flowering Final Report 2009 - Trial 1202 1 RHS Trial of Crocus, spring flowering Introduction to Crocus, spring flowering Genus of dwarf, cormous perennials with small, goblet shaped flowers made up of 6 tepals. Plants are semi-erect with linear, lance shaped leaves which often have pale silvery central stripes. Crocus are widespread in Central and Southern Europe, North Africa, Middle East, Central Asia and Western China where they are found in a wide range of habitats including woodland, meadows and coastal regions. Objectives The objectives of the trial were: • To assess a range of currently available spring-flowering Crocus species and cultivars • To recommend the Award of Garden Merit to taxa considered excellent for ordinary garden use • To determine correct nomenclature • To produce a permanent record through herbarium specimens, photographs and written descriptions for the RHS Herbarium at Wisley • To demonstrate the performance of this plant group to Wisley Garden visitors over a four year period, in a frame-yard and in the open ground Judging The Rock Garden Plant Trials Assessment Panel will assess entries in the trial for the Award of Garden Merit using the following criteria: • Vigour • Resistance to disease • Impact • Flower • Foliage • Nomenclature Entries There were 155 entries in the trial submitted by various individuals and nurseries throughout the UK and Europe and from The Royal Botanical Gardens, Kew. Crocus Spring Flowering Final Report 2009 - Trial 1202 2 Cultivation Corms were received in late summer/early autumn 2006 and were planted into 13cm lattice pots in the relevant soil type. Two different soil types were used, one for alkaline dry dormancy groups and one for acid/neutral moist/dry dormancy groups. Prior to planting, corms were dusted with a fungicidal powder to minimise disease and rot. Soil Types Alkaline Dry Dormancy Acid/Neutral Moist/Dry Dormancy 2 parts John Innes No. 3 1 part John Innes No. 3 1 part leaf mould 2 parts leaf mould 1 part grit 1 part grit 8g/l Vitax Q4 8g/l Vitax Q4 1.7g/l Dolodust 0.28g/l Intercept 0.28g/l Intercept In 2006 the Crocus were planted in the Alpine Frame Yard where the beds could be covered to prevent damage in severe weather. The beds were covered with fine chicken wire and dressed over with gravel to prevent damage to the corms by mice. Both the chicken wire and the covering to the bed prevented bird damage during this period. In 2008, the entries were lifted from the Alpine Frame Yard in their lattice pots and plunged into a raised bed on the trials field. This bed was filled with a mixture of soil and grit and then dressed with a layer of gravel over the top. Pest and Disease The following pests and diseases were encountered during the trial: • Root rot and lesions – caused by Phytophthora citricola; Phytophthora cinnamomi and Pythium violae • Virus – Arabis Mosaic Virus and Iris Severe Mosaic Virus Other Findings C. biflorus subsp. Tauri flowered particularly well in 2009 due to the very cold winter. This was thought to be an excellent cultivar but is too dependent on cold winter temperatures to gain an AGM. Crocus Spring Flowering Final Report 2009 - Trial 1202 3 Public Vote The public visiting the trials field were invited to vote for their favourite Crocus. Voting slips were available between 23rd February and 3rd March 2009. 21 cultivars were voted for during this time and these were distributed as follows: Public Vote for Crocus C. 'Jeanne d'Arc' 16.4 C. 'Margot' 13.4 'C. 'Little Amber' 10.4 C. tommasinianus un-named seedling 9.0 C. biflorus subsp. tauri 7.5 C. vernus x tommasinianus pale -flowered [JG6] 6.0 C. biflorus subsp. tauri 4.5 C. olivieri subsp. balansae 'Zwanenburg' 4.5 C. 'Zenith' 4.5 C. tommasinianus x vernus 'Pieta' 3.0 C. 'Ruby Giant' 3.0 C. × luteus 'Stellaris' 3.0 C. 'Dorothy' 3.0 C. × luteus 'Golden Yellow' AGM H4 1993 1.5 C. 'Lavender Striped' 1.5 C. tommasinianus [JG2] 1.5 C. 'Ego' 1.5 C. malyi 1.5 C. 'Vanguard' 1.5 C. 'Goldilocks' 1.5 C. 'Ard Schenk' 1.5 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 % of Votes Crocus Spring Flowering Final Report 2009 - Trial 1202 4 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: H4 – hardy throughout the British Isles Plants Awarded AGM Crocus angustifolius ‘Bronze Beauty’ AGM (H4) 2010 [Trial No. 3] votes 10-0 Flowers January to March Pale yellow flowers with purple veining and feathering and orange styles. “Long flowering period and hold flowers well. Distinctive colour combination.” Sender: Mr J Rukšāns Crocus etruscus ‘Zwanenburg’ AGM (H4) 2010 [Trial No. 136] votes 10-0 Flowers January to March Violet flowers becoming almost white at base with paler feathering and veining and orange styles. “Attractive soft violet flowers of even form. Good garden plant.” Sender: Jacques Amand International Crocus Spring Flowering Final Report 2009 - Trial 1202 5 Crocus ‘Goldilocks’ AGM (H4) 2010 [Trial No. 20] votes 14-0 Flowers January to March Golden yellow flowers with greyed-brown blotch in centre and red-orange styles. “Good constitution and increases well. Known to cope well on clay soils also.” Sender: Mr J Zweeris Crocus x luteus ‘Stellaris’ AGM (H4) 2010 [Trial No. 62 & 71] votes 14-0 Flowers December to March Bright golden yellow flowers with bold purple- black stripes and yellow filaments. “Very attractively coloured flowers which appear before leaves have fully developed. Increases well.” Sender: Mr B Mathew & Mr J Zweeris Reconfirmed AGMs Crocus chrysanthus ‘Zwanenburg Bronze’ AGM (H4) 1993 [Trial No. 41] votes 10-0 Flowers December to March Dark reddish-brown flowers with yellow inner surface and edges and orange styles. “An excellent garden plant that has been around for decades. Early flowering. Suffered some frost damage in the very cold snap in early 2010.” Sender: Mr J Zweeris Crocus corsicus AGM (H4) 1993 [Trial No. 170] votes 11-0 Flowers January to March White flowers with violet inner surface and purple stripes. “Very attractive and highly floriferous. Has proven its worth as a garden plant over many years.” Sender: RBG Kew Crocus Spring Flowering Final Report 2009 - Trial 1202 6 Crocus flavus subsp. flavus AGM (H4) 1993 [Trial No. 39, 42, 43, 44 & 45] votes 12-0 Flowers December to March Golden yellow flowers with paler yellow filaments. “Highly floriferous with attractive flowers. Establishes well in light soil and seeds widely although this leads to tonal variation in colour.” Sender: Mr J Zweeris Crocus malyi AGM (H4) 1993 [Trial No. 67 & 75] votes 13-0 Flowers January to March White flowers with greyish-purple and yellow base and orange styles. “Very attractive flower which grows well in the garden. Best on alkaline soil.” Sender: RBG Kew & Mr J Rukšāns Crocus sieberi ‘Bowles White’ syn of ‘Albus’ AGM (H4) 1993 [Trial No. 128, 144 & 145] votes 14-0 Flowers January to March White flowers with egg yolk yellow base to the petals and orange filaments. “Excellent garden plant. Produces large numbers of attractive flowers with rich, golden- yellow throats.” Sender: Broadleigh Gardens, Jacques Amand International & RHS Plant Centre Crocus ‘Snow Bunting’ AGM (H4) 1993 [Trial No. 29 & 34] votes 14-0 Flowers December to February White flushed buff flowers with dark purple longitudinal streaks and bright orange styles. “Floriferous and attractive. A good garden plant which has proven its worth over many years.” Sender: Avon Bulbs & Mr J Zweeris Crocus Spring Flowering Final Report 2009 - Trial 1202 7 Crocus tommasinianus AGM (H4) 1993 [Trial No. 86-9, 93-101, 103-5, 110 & 139-40] votes 11-0 Flowers December to March Violet to purple flowers with silvery grey to white base and orange-yellow filaments and styles. “Attractive, vigorous garden plant guaranteed to give a good display. Seed and hybridise freely giving a wide range if shades.” Sender: Avon Bulbs, Broadleigh Gardens, Dr J Grimshaw, Jacques Amand International, Mr B Mathew, Mr J Rukšāns, RBG Kew & RHS Plant Centre Crocus x luteus ‘Golden Yellow’ AGM (H4) 1993 [Trial No. 138] votes 14-0 Flowers December to March Golden yellow flowers with central brown feathered stripes and golden yellow filaments. “Cheerful, bright coloured flowers. Robust garden plant.” Sender: Jacques Amand International Awarded AGM Subject to Availability The following entries have been recommended for the AGM but cannot receive the award until they are available to the public in retail catalogues. It is the responsibility of the sender to inform the Trials Office at Wisley that all queries have been resolved. Crocus ‘Margot’ AGM (H4) 2010 [Trial No. 119] votes 13-0 Flowers January to March White flowers with central pale yellow flush from base to tip and pale orange-yellow filaments. Inner tepals are violet with fine white margins. “Good vigorous garden plant with attractive contrast between outer and inner tepals. Very distinct.” Sender: Rev. Blakeway-Phillips Jacques Amand prepared to take up and make available Crocus Spring Flowering Final Report 2009 - Trial 1202 8 Crocus ‘Midas Touch’ AGM (H4) 2010 [Trial No.