Paphiopedilum Culture

Every now and then I will post some cultural information about different kinds of orchids. Today's topic is the fabled Paphiopedilum, or slipper orchid. If you live in a temperate region, you may have heard of Cypripediums, or lady's slippers. These are the temperate cousins of Paphs; they both belong to the Slipper Alliance; later in the year I will post info about Cyps as well as the New World tropical slippers, Phragmipediums. Paphs are endemic to southeast Asia.

Generally, paphs prefer indirect light; good places are an east windowsill, a shaded west windowsill, or in the centre of a well-lit room. They should never dry out but should also never be overwatered; the frequency of watering depends on the mix you use, but I water every other day. Fertilizer is just as important to paphs as to other orchids. There are many different methods, but I fertilize with a specialty orchid formula every week when in active growth and every two weeks when not. These formulas are readily available at your local garden centre - follow the label directions. Paphs also need humidity; the classic "humidity tray" method works just fine: cover a tray with pebbles or gravel and add water so that the water does not reach the bottom of the pot (this will rot the roots), and refill when needed. You can buy ready-made humidity trays at your local orchid dealer which do not need pebbles. Temperatures for these guys should be intermediate, with a minimum winter night temp of 13C/55F and a summer day max of 27C/81F. More air movement is required as temps and humidity increase; use a small electric fan. Repotting is required every one or two years: simply tease the roots carefully out of the pot. Then, remove the old mix and cut off any dead/rotten roots, centre the plant in the new pot and add new mix. The mix should be soaked over night before use; use a fine-grade fir bark medium which is available at your local orchid dealer.

Depending on the type of paph you have, these basic care requirements will need to be modified slightly as folllows:

Maudiae: Small plants have large flowers and mottled leaves. Lower light and warmer temperatures.
Complex: Medium sized plants have large flowers with wavy petals and plain green leaves. They prefer standard conitions as explained above.
Parvisepalem: P. delenatii, its relatives and its hybrids. These have delicate, round flowers and gorgeous mottled leaves. Small plants, they require standard conitions as outlined above, but should have a coarser medium.
Brachypetalum: These are curious plants, small with round, bird's egg flowers and mottled leaves. They are harder to grow than the other types. Provide lower temperatures, low light, more coarse medium and much calcium (through plant vitamin supplements or dolomite lime, or oyster shells); also, use only distilled or reverse osmosis water and never tap water.
Multifloral: Though most paphs bear only a single flower, some bear two or more. These have plain green leaves and require warmer temps and higher light.