Cymbidium Orchids
Summary
Growing cymbidiums is not too hard but remember that they do not grow in ‘earth’ as most other plants do. Cymbidiums naturally occur in trees, in forest areas rich in decaying organic matter. When growing in pots, adjust the conditions to achieve the drainage they need. The drainage hole in a pot used for an orchid should be enlarged to about 3 times the diameter of the usual hole. Re-potting should be done in October or November, when flowering is finished.
Orchids require a very open, free draining potting mix and a specific orchid mix must be used when growing these plants.
Make sure your plants are in a position to receive only morning sun. Cymbidiums
are large plants and need a position where the leaves can spread out fully,
so give them plenty of room. Flower spikes are initiated with cool
nights at the end of February or beginning of March. When you see the
first signs of a flower spike emerging from the base of the orchid, it is
useful to place a stake in the pot so that as the spike grows it can be tied
for support and protection. If growing them in a cold climate, ensure
that orchids are under a covered structure, but receiving some direct morning
sun.
The plant growth period for cymbidiums is October to February.
- In areas where the weather is hot and dry during this period some humidifying and cooling is required.
- If the area is cold in the flowering period (March to September) then some form of protection will be needed.
- The aspect which a plant faces is important, it should be east to north,
never west to south.
It is best to concentrate on applications of fertiliser which suit the stages of growth and flowering. Most garden centres sell specific orchid fertilisers, one suitable for the growth stage, and one for the flowering stage.
Potting materials can be quickly ruined by poor watering methods. Any alkaline water, such as bore water is totally unsuitable for orchids. When to water depends on the growing conditions, the amount of shade, the temperatures, humidity and type of potting mix used. Watering must be a personal, weather dictated operation. Cymbidiums do not use great quantities of water and it is possible to overwater in the growing period of October to February, just as easily as in the cooler and flowering part of their cycle, from March to September. The possibility of overwatering is intensified by the use of plastic pots. The only reliable way to is to check the potting mix, poke about in the surface of the mix. If the mix is damp then the plant does not need water for a day or so. If the mix is dry, then water thoroughly over the whole surface of the mix. In hot dry weather you may need to water daily.
Growing cymbidiums in wire baskets with coconut fibre liners is quite successful
for the home gardener as the water drains away much more readily and overwatering
is not such a problem.
Monthly Guide
January
Generally hot weather so water around and over plant to humidify. Don’t
water too late in the evening and don’t allow roots to dry out, or
overwater. Feed fortnightly with specific orchid food for the ‘flowering
period’.
February
Very
warm conditions so watch watering and provide humidity. Feeding, watering
etc, same as for January. Fertilise with an application of blood & bone
mixed with sulphate of potash (6 parts blood & bone to 1 part potash)
and sprinkle this
into
the top of the potting mix.
March
Watch for flower spikes emerging. Maintain
same feeding and watering regime.
April
If there is any danger of frost,
plants should be covered or moved indoors at night. Plants still need
to remain outside during the day in a position where they will receive morning
sun. Watering and feeding should be done only in the morning – do
not overwater. Continue feeding with ‘flowering’ fertiliser. When
flower spikes begin to emerge it will be necessary to prevent damage by slugs
and snails as they can consume an emerging flower spike overnight.
May
Same as for April but feeding
and watering should be reduced. Carefully stake up flower spikes as
they are brittle and easily broken. Continue to protect from damage
by snails and slugs.
June
Plants should now be moved
to a more protected area to prevent damage from frosts, wind and rain. This
is the beginning of the ‘rest’ period for Cymbidiums so stop
feeding. Watch flower spikes for ants, aphids, scale, and spider mites. Continue
to watch for snails and slugs. Water very sparingly and keep moist
only if the plant is flowering. Plants can be left indoors as long
as they have plenty of light and air circulation, but not in a room which
is too warm from a heating system.
July
Same as for June.
August
Remove any spent flower spikes. Water sparingly – keeping
just moist. Same
as for June.
September
If
flowering is finished, this is the time to re-pot if re-potting is necessary.
October Check general health of plant and remove any damaged or diseased
sections. Use one of the mixes suggested on the first page and
re-pot the plant. Sprinkle plant food around top of pot (dynamic lifter
or similar). Water the plant and place it in an area where it will
receive morning sun and then dappled sun/shade in the afternoon. Plants
should still be protected from snails and slugs and should be up off the
ground if possible. Cover if there is any danger of frost.
November
Change
to the fertiliser for the ‘growth’ period and feed the plant
with this fertiliser at half strength every week. Spray the foliage
of the plant with the same half strength mix fortnightly. If there
is no rain, keep plants sufficiently watered and keep ground around them
damp to provide humidity. At the end of the month sprinkle 1 spoonful
of slow release fertiliser on top of each pot.
December
Same
as for November. If hot, spray plant for humidity more often.
Ann Costelloe