How to grow Zygopetalum

Temperature

Zygopetalums grow best in intermediate to moderate temperatures. They are soft-leaved orchids and do not like direct sunlight, especially during the hotter months, as this can quickly damage their foliage.

Light

Around 70% shade is ideal for Zygopetalums. In winter, they can tolerate slightly higher light levels on sunny days, as the cooler temperatures mean the leaves are less likely to overheat. As with most orchids, gentle direct light very early in the morning or late in the afternoon is usually not harmful.

Water and Humidity

Zygopetalums prefer humid conditions, moderate shade, and generous watering during the active growing season. Once the new pseudobulbs have fully formed, watering should be reduced slightly, as the plant’s growth slows.

Fertiliser

Zygopetalums are not particularly fussy about fertiliser ratios, so either slow-release fertiliser or liquid feed can be used. A balanced liquid fertiliser such as 20-20-20, applied at half the recommended label strength throughout the year, works well. Organic fertilisers may also be useful as a source of trace elements and can be applied as a top dressing in spring. Avoid fertilisers with high nitrogen levels, as these can cause the foliage to become brittle, stretched, and more prone to damage.

Potting

Like many orchids, Zygopetalums respond best when divided and repotted as new growths begin stretching upward. They are quite succulent, so care should be taken when dividing them, as the pseudobulbs can be easily bruised or broken. Their roots are soft and may break during division, so newly divided plants should be given extra care while they re-establish.

A free-draining potting mix works well, such as a blend of coconut chip, bark, and perlite. Smaller plants can usually be moved into larger pots throughout most of the year, except during winter, provided the roots are healthy and white. Adding dolomitic lime to the potting mix, or applying it as a top dressing twice a year, can help make the foliage firmer and less prone to bruising or breaking.

References

Bechtel, Cribb and Launert, The Manual of Cultivated Orchid Species, 3rd edition, MIT Press, 1992.

Hawkes, Alex, Encyclopaedia of Cultivated Orchids, Faber & Faber, London and Boston, 1965.

Pridgeon, Alec, The Illustrated Encyclopedia of Orchids, Timber Press, Portland, OR, 1992.

Original author: Andy Easton, New Horizon Orchids, September 2006.