A presentation given by Ian Dorman at the meeting of the British Paphiopedilum Society (BPS) held on February 9/10 2013
Ian introduced himself and explained that the idea for the talk had occurred on the 25th anniversary of the date he had originally started growing orchids which was now 5 years ago and since then he had given the talk to a number of orchid societies in the UK; hence the title which should now probably read …. “the first 30 years”. There would only be a small amount of Paph taxonomy included in the talk which was best left to the botanists with the emphasis being strongly towards growing plants.
Ian showed a slide of Paphiopedilum Copper Spice “Menston” which was the first orchid he had ever purchased from Mansell & Hatchers in 1983 and the spark for the talk was the fact that this same plant started to bloom almost 25 years to the day since he had first set foot in Mansell & Hatchers. Some members may recall a short article Ian had written for the BPS Journal in which he described his humorous experiences in trying to find Mansell & Hatchers on that fateful day; a day which started a passion for orchids which continues after 30 years.
Ian explained that he had never seen a plant as wonderfully exotic as Paphiopedilum Copper Spice before he set eyes on it at Mansell & Hatchers and of course at around £7 it was a small fortune to him at that time but he had to have it. Paphiopedilum Copper Spice is what we now call a novelty hybrid being the result of a cross between spicerianum and a complex hybrid Copperware made by Ratcliffes. The reason the plant was on sale at Mansell & Hatchers was because of the reciprocal arrangements which existed with Ratcliffes at that time during the dark days of the Gray ownership of the 2 firms which is another story. Ian’s passion for growing Paphiopedilums was cemented a couple of years later when Paphiopedilum Copper Spice was exhibited on the display table at a Sheffield & District Orchid Society meeting with 4 large bold flowers and the late Dr Jim Binks who was doing the table show was full of admiration and praise for this particular clone and Ian was completely hooked.
Ian summarised the main geographical areas where extant populations of Paphiopedilum species occurred in the wild from the mountains of India to the steamy jungles of Borneo, Sumatra and the Solomon Islands so any cultural guidelines had to be of a general nature with specific cultural information required on a species by species basis dependant on geographical location. He regarded all Paphiopedilums as essentially humus epiphytes which had significant implications for their culture in a greenhouse or in the home. For taxonomy purposes Ian preferred to follow Cribbs’ classification system as he found this relatively simple and straightforward, although there were obvious shortcomings. Ian commented that he personally felt there were between 80 to 90 valid Paphiopedilum species with more being discovered all the time so he regarded himself as a “lumper” rather than a “splitter”
Ian presented a number of slides showing external and internal views of his greenhouse which was approximately 30 feet long by 10 feet wide split into 3 sections ie warm, intermediate and cool. He didn’t believe there were any cool growing Paphiopedilums so his collection was split between the warm and intermediate sections Warm represented an average minimum temperature of 17C during Winter and an average maximum of 32C during Summer with corresponding intermediate temperatures 14C and 28C respectively. Due to Ian’s busy work schedule and the large size of the collection of Paphiopedilums the greenhouse had been set up with as many automatic controls as possible which made it an expensive investment, however those growers with less resources shouldn’t despair as it was perfectly possible to grow good quality Paphiopedilums on a much lower budget. Ian then summarised some of the key elements in achieving good growing results based on his experience. He emphasised that other growers achieved good results with different methods:
Know your plants, check where they come from in order to assess their specific cultural requirements. Start with easier plants such as spicerianum and insigne before moving onto narrow endemics where maintaining cultural best practice is more crucial
Gas central heating via a dedicated Worcester boiler is used throughout the greenhouse to provide the correct temperatures for the plants. Each section has control valves with electronic thermostats to maintain individual temperatures as required to suit the plants.
The greenhouse orientation is East to West so the long South Side is protected by 70% shade cloth on the outside which can be manually controlled by ropes and pullies. No shading is applied on the North side under normal circumstances, although occasionally some internal shading is needed to control light levels.
Gro Lux lights are used to supplement and extend day light in the autumn and winter months. Minimum requirement is 11 hours good quality light in winter There are sliding ventilation vents down each side of the greenhouse at floor level protected by wire mesh to prevent access by pests. Each section of the greenhouse has a dedicated extractor fan to control temperature in summer. Relatively cheap oscillating fans are used at low level speeds to provide some air movement at all times.
Potting and Potting Compost
A golden rule for Paphs is to use as small a pot as possible. NEVER over pot as this will result in a slow death. There are a multitude of potting composts used for Paph culture, however Ian still favours a bark based compost consisting of 60% good quality fir bark plus equal parts of NZ sphagnum moss, large perlite (sponge rock) and horticultural foam. Dolomite lime is added at one teaspoon per litre of compost. Re-potting should take place every 2 years or so depending on plant growth and the condition of the compost. Some Paphs such as rothschildianum do seriously resent re-potting probably due to their lithophytic nature so extreme care is necessary in not damaging the roots, although the modern seed raised clones do seem to tolerate it better.
Watering, Water Quality and Humidity
This is absolutely key to successfully growing Paphs. RO and rain water are usually best with tap water only used where the dissolved salt levels are extremely low. The pH level should be as close to neutral as possible. Frequency of watering depends on greenhouse conditions. Never let Paphs become dry at the roots even in the winter months when pipe heat and artificial lighting can reduce humidity levels which should be maintained in the 70% range. There are a number of ways of maintaining the required humidity levels; Ian uses foggers purchased from Simply Control.
Pests & Diseases
Unless there are any obvious cultural problems, in the event that a plant is not doing well, instead of changing growing conditions check immediately for any pests which may be inhibiting growth. Mealy bug is the main concern for Paphs which if allowed to develop unchecked will rapidly turn into an infestation which is impossible to eradicate given the lack of effective systemic insecticides. Therefore it is important to deal with mealy bugs at the first sign of their presence in the greenhouse. Local applications of methylated spirits usually has the desired effect, although prevention of pests entering the greenhouse is the best course of action. Bacterial and fungal infections are of much greater concern as these can quickly spread throughout the greenhouse. It is often difficult to pinpoint the source of such infections, however an individual plant suffering stress can exhibit symptons and quickly pass these on to other plants in the collection. Where individual plants are infected it is important to isolate these and remove carefully offending leaves. Spraying with a good quality fungicide is usually effective and cinnamon can be used to treat localised areas.
A balanced fertiliser is necessary to promote optimum growth, particularly to replace trace elements where RO water is used. The normal feeding regime is to at the rate of 500 micro siemens throughout the year.
Most Paphs will flower with at least 2 mature growths. It is important to stake emerging flower spikes at an early stage to avoid kinking. Opening flowers should not be tied too early as some Paphs have a tendency to hang their heads. When exhibiting plants foliage should be clean and pest free with all detritus removed from the compost surface.