Cultural Notes for Cattleya Alliance

Cattleyas have earned the reputation as the “Queen of Flowers” and are known to the public as the ultimate in floral corsages. Corsages are today sadly out of date, but the plants are cultivated for the showy and longlasting blooms. More than 50 species of the flamboyant, intricately designed flowers are found growing wild in the foothills and mountains of Central and South America. While some species are offered by growers, the most popular plants are manmade hybrids derived from the hybridising of Cattleyas with some of their close relatives to produce a range of colour, size and form.


Cattleyas require a good amount of light. Early morning sun, accompanied by high humidity and moderate temperatures, are excellent. Protective shade should be heaviest from noon to mid-afternoon (3pm). They thrive in maximum sunlight, without excessive leaf burning temperatures. A good guide to proper light is the colour of the foliage – it should be mid-green, not too dark or pale green.


During the hot summer months the plants enjoy being misted two or even three times a day. Be sure that foliage is dry by nightfall. I like to keep the floor wet in preference to misting the foliage in the Garden Route area as we are prone to fungi. TEMPERATURES: Basically, Cattleyas enjoy the same temperatures as you, nights of 15° to 18°C with days of 21° to 29°C. They will withstand short periods in the low 10’s and as high as 35°C, but prolonged periods are harmful.


Possibly the most difficult part of growing cattleyas for the beginner to understand is when to water. Cattleyas can withstand long dry periods – they like to be alternately well watered and dried out. Many factors affect when to water – weather conditions, size of pot, size of plant, potting medium, etc. The pot will feel quite light when picked up. To determine moisture content of potting mix, remove the label and feel it for moisture. If moist, don’t water. If the surface of the label is dry, water the plant thoroughly. Some plants will require water more frequently because they will ‘use’ more. Generally speaking 15 to 20cm pots will require thorough watering every 5 to 7 days in hot weather and every 10 to 14 days in cool weather. For smaller pots, increase frequency. During prolonged cool or cloudy periods, once or twice a month may suffice. Always water well allowing water to run water through the potting medium to thoroughly soak the bark throughout. This also draws oxygen through the medium aerating the roots. I do all watering by hand using a hose with a rose nozzle.


Fertilize your plants with Starke Ayres ‘Growing Orchids’ formula during the early summer months of September through December at half the recommended strength, every second watering. This can be alternated with an organic fertilizer should you wish. Thereafter I recommend the Starke Ayres ‘Nutrifeed’ balanced hydroponic formula for the rest of the year. Do not forget that in the winter when you are watering less you will be fertilizing less. If you know the blooming time of your Cattleyas, you can give them the ‘Flowering Orchids’ 6:20:30 formula 4-6 months prior to blooming. See accessories list for all fertilizers.


Cattleyas are epiphytic, ‘semi air growing’ plants, growing on the bark of trees, in their native habitat, and not in soil. Outeniqua Orchids has obtained an excellent hard pine bark which retains moisture for short periods of time, drains easily and quickly, is sufficiently acid, does not decompose rapidly and provides an excellent base for the epiphytic roots of most orchids. For blooming size cattleya plants we recommend the 15- 19mm particle size. Cattleya potting medium is available in 5kg bags from the Nursery.


Repot when plants outgrow the pot and the rhizome extends over the edge of the pot, or when the pine bark potting medium begins to decompose and no longer retains its chunky appearance. Large plants should be repotted every 2 – 3 years. Roots often grow outside the pot and are simply aerial roots and do not indicate a need for repotting. Do make sure pots have good drainage holes for aeration, it is also a good idea to make a few more holes in the bottom of the pots or even in the sides. Cattleyas can also be grown successfully in teak baskets. Line the basket with coir to prevent the mix falling through and then pot as usual. Cattleyas will provide a tremendous amount of enjoyment and frequently become the most ‘talked about’ conversation piece in your home!