PAPHIOPEDILUMS FOR NEW GROWERS by Alan Hope

Paphiopedilums are found in many of the countries immediately north of Australia, with the largest concentrations being located from Indonesia to southern China and extending to northern India. While we tend to think of these regions as being tropical and hence hot and humid the year round, the majority of paphiopedilums grow in mountainous areas where the high elevation, constant air movement, and shading by trees and bushes, reduce temperatures to much more temperate levels. Accordingly, many of the species paphiopedilums can be grown satisfactorily in cool to warm protected conditions, while those hybrids which have cooler-growing paphiopedilums in their back-grounds, will tolerate even colder conditions.

HOUSING. 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.

AIR MOVEMENT AND LIGHT. Paphiopedilums appreciate good air movement. This can be provided by using a fan in a glasshouse or by placing the plants in an airy position indoors, but avoid a draught. Light is also important, however to so place plants away from direct sunlight, especially sun shining through a glass window, as this can burn the leaves and stunt growth.

WATERING. Paphiopedilums prefer a damp but not soggy mix and should not be allowed to dry out completely. Watering is therefore required throughout the year, once a week in winter and two to three times a week in summer, depending on weather conditions. Gentle overhead watering using a water wand is satisfactory. If water collects in the centre of the growth use some paper towel to soak up any excess.

POTTING & POTTING MIX. Paphiopedilums should not be over-potted and will grow well in a small pot. While large plants can be left in the same mix for up to two years, smaller plants respond to annual repotting, usually in spring. A bark-based mix (5-10 mm) provides for quick drainage while retaining some moisture. A liquid fertiliser used fortnightly (or monthly) at a quarter to half-strength will ensure good growth and flowering.