‘Slipper Orchids‘ are members of the sub-family Cypripedioidae, which comprises four main genera:
- Cypripedium (terrestrial orchids from Asia, Japan, Europe and North America),
- Selenipedium (terrestrial orchids from Central and South America),
- Phragmipedium (from South America) and;
- Paphiopedilum (throughout Asia)
The following paragraph is from an article entitled ‘Paphiopedilums – Different But Not So Difficult‘, by OSCOV contributor Robert Willmott. He notes that all of these genera have the characteristic ‘pouch’ or ‘ladies slipper’ and a column structure that differs from that of all other orchids. Generally, only two of the above genera are commonly cultivated in Victoria. They are the Phragmipedium, which we see fairly frequently, and of course the Paphiopedilum. The first paphiopedilum (or cypripedium, as they were then known) introduced into English glasshouses (in 1819) was Paphiopedilum venustum (pictured below). Many new species were introduced to cultivation in the famous plant-hunting times later in the 1800s.
Many thousands of hybrids have been made since then and it is possible to have tremendous floral diversity in a collection of paphiopedilums, with flowers throughout the whole year. Each group has slightly different cultural requirements and some of these will be discussed at the conclusion of his article.
Another article on cultivation, ‘How To Grow Paphiopedilums’, outlines that they are among the most popular orchids. In nature they are found in many of the countries immediately north of Australia, the highest concentrations being located in Indonesia, Malaysia and Thailand, as well as in southern China and northern India. While we tend to think of these regions as being tropical and therefore hot year round, the majority of paphiopedilums grow in mountainous regions where the high elevation, constant air movement and shading by trees reduce temperatures to much more temperate levels. Therefore, many of the species can be grown satisfactorily in cool to warm protected conditions, while those hybrids with cool-growing species in their parentage will tolerate cooler conditions.
The successful housing for them is discussed in Alan Hope’s article ‘Paphiopedilums For New Growers‘. The following is an excerpt from his article. “Given Melbourne’s climate of hot, dry summers and cool, wet winters, paphiopedilums require some protection throughout the year. In summer the plants need to be shaded to avoid sunburn and excessive heat, while in winter protection is required from rain, hail, frost and low temperatures. During winter a heated glasshouse is best for those with a large collection of paphiopedilums while smaller collections can be grown perfectly well indoors on a shaded window sill or bench. If desired the plants can be moved outdoors in summer to a well shaded position and placed off the ground to ensure air movement”.
Further tips on cultivation are provided by Stephen Early in his article entitled ‘Paphiopedilums and Their Cultivation’. Here, Early discusses growing media, watering, fertilising and growing conditions. The following are taken from his article.
- Growing Media. I grow my plants in a bark-based mix containing 17% Canunda shell and 9% granite chips (by volume). I use 3-5 mm bark for pots up to 100 mm diameter and 5-10 mm bark for larger pots. The shell and granite fulfill two functions. They help to create similar conditions to those in Nature and to keep the mix ‘sweet’ by neutralising any acidity that develops. Using this mix, I find few plants with unhealthy root systems.
- Watering and Fertilising. I water my plants when they need it, usually daily in summer and weekly in winter. The plants are also fertilised during four out of every five waterings, using liquid fertilisers; I never use slow-release fertiliser in the mix. On the only occasion I used a slow-release fertiliser the plants suffered marked root loss.
- Growing Conditions. My plants are grown in an aluminium-framed glasshouse heated to a minimum temperature of 12°C, lined with Marix cloth and covered with 50% shade cloth. Smaller plants are grown on a wet bench and larger ones on wire mesh benches with water-filled corrugated fibreglass trays below to provide a high level of humidity, similar conditions to those that the plants experience in Nature.
For information on Pests and Diseases, refer to the article ‘Multi-Flowering Paphiopedilums’ by Alan Hope. In his article, he identifies the main pests as mealy bugs, slugs, snails and seasonal grubs. Mealy bugs are difficult to eradicate as they hide away and their eggs remain viable for some time. A systemic spray is probably best but follow-up is essential a few weeks later. Be careful to protect emerging flowers as the spray can damage them. To control slugs and snails place some snail bait in the pot, even when it is suspended, as these pests seem to be able to find a way to a choice bud wherever the pot is located. The same applies to grubs – continual vigilance, followed by appropriate treatment, is essential.
- See also our Paphiopedilum photo gallery.
- For further information about orchid care at Southern Suburbs Orchid Society (SSOS) or membership enquiries, please do not hesitate to Contact Us.