How to Care for Your Orchids
Based on cultural instructions originally generated by McBeans Orchids.
Incorporating BMOS Members Suggestions.
CATTLEYA
Distinguished along with the hybrids and allies by their flamboyant flowers. Cattleyas originate from South America, some from cooler regions of the higher Andes and some from warmer climes. On the whole the larger the flowers the warmer the growing conditions necessary. Cattleyas have been crossed with many different allied genera to produce intergeneric hybrids such as BRASSOLAELLIOCATTLEYA, SOPHROLAELIOCATTLEYA, LAELIOCATTLEYA and CATTLEYTONIA.
FLOWERS
These orchids usually bloom in the spring or autumn depending on type with flowers lasting for 3 or 4 weeks. The flowers are usually of an intense colour, ranging from pure white through pinks and lavenders to strong yellows, greens and reds.
CULTIVATION
TEMPERATURE
Large flowered types, NIGHT 13 degrees C. DAY 18 degrees C. Smaller types, NIGHT 11 – 13 degrees C. DAY 15 degrees C.
LIGHT
In the natural habitat Cattleyas grow in the semi shade so in the home they need bright conditions without direct sunlight during the hottest part of the day. Eastern or Western windowsills are ideal BUT they will not tolerate draught or being above a radiator or heater.
WATERING
During the summer when the temperatures are high water frequently but ensure that the compost dries out between watering. (One way to do this is to push a cotton bud down the side of the pot to check. The weight of the pot will also be an indicator once you are used to the differing "feel" when you lift the pot). NEVER let the plant stand in water, as this will tend to rot the roots. Reduce the watering as the temperature and light levels drop and during the winter water infrequently so as not to stimulate growth which will be weak. A "drying out" or rest period from November to March is probably helpful and don’t worry if the plant flowers during this time. Gradually increase watering from late March onwards as the new growths will have time to "ripen" in the higher temperatures and light levels of summer.
FEEDING
There are many commercial feeds on the market and many Orchid Nurseries have their own mixes that they would, of course, recommend. The greatest problem is the build up of salts in the compost that could "burn" the roots and the general recommendation is to flush through with water only every 4th watering. Using liquid fertilizer such as "Baby Bio" at half strength every 2nd watering during the growing season, i.e. end of March through to the end of September will work with perhaps the odd feeding with a high potash feed (tomato feed) during September or when flower spike(s) are to be seen. Once you are more at home with growing orchids then, perhaps, you can look into more specific orchid feeding regimes.
HUMIDITY
Humidity is highly important for the Cattleya Alliance and in the home the only sure way to provide this, even if the plant(s) are in the Kitchen or Bathroom is to stand the pot in a saucer of gravel which is keep constantly wet BUT with the base of the plant clear of the water. This will provide a microclimate of humidity due to evaporation around the plant. Low humidity can be quite easily detected as the pseudobulbs will show a tendency to shrivel – another cause of failure with orchids, shrivelling doesn’t necessarily mean lack of water!
COMPOST
As epiphytes they need open, well aerated and free draining medium. The general recommendation is to try and match the conditions found naturally so use a mixture of course and fine bark or similar material that gives the necessary conditions.
POTTING
Not as necessary as once thought, i.e. every year. Re-pot when the compost has started to degrade, (degrading bark will give off a somewhat unpleasant smell when it is wetted). Potting should be carried out in spring just about the time new growth is just evident. Re-pot in damp compost in the same size pot or, at the most a very slightly larger one, (epiphytes grow on trees so space is restricted in nature). Once re-potted leave the compost to dry out before watering as this will stimulate and encourage strong anchor root growth.