Orchids

Just some notes on growing orchids from a talk I attended. Feel free to add your own tips.

Cymbidiums

Grow well in a cool climate, will be quite happy outdoors in sheltered areas especially under a deciduous tree. Cymbidiums will flower annually if fed correctly.

In autumn or about February, steep a sachet of dried blood (from garden centre) in a bucket of water for 2 or 3 days (will be stinky). Discard the sachet and water cymbidiums or anything else that flowers annually with the resulting liquid. This will give them a kick start and should result in flowering in August/September. In early spring (September)feed with about a tablespoon of osmacoat or similar slow release fertiliser. This activates with heating and cooling and will last about nine months so not other feeding, apart from the dried blood in autumn is necessary.

When repotting cymbidiums break off the back bulbs all at once rather than one at a time. This will get rid of the dead roots easily. Breaking off the back bulbs one at a time tends to leave the dead roots behind. Don't trim live roots, if they are too long just spiral them around in the base of the pot.

Compact cattlinas and dendrobiums are also suitable for a cool climate but are best brought indoors in winter.

Phalanopsis (moth orchids)

These require a warm climate so are only suitable for indoors. Grow in a clear pol so that roots get access to light otherwise they will grow out the top of pots. To get them to flower put it a cold place (the toilet usually is cool enough) around ANZAC day for 6 weeks then bring them back into a warm room. It should them flower around September.

Potting on and repotting
Don't use special orchid mix as sold at a garden centre. Use clean bark without the cambium tissue (leathery layer) or any wood tissue or dusty particles (stones are fine) and nothing else, orchids will live happily for 20 years or more potted in plain bark.

When potting on there is no need to removing them from the old pot. Just put the orchid still in it's pot in the new bigger pot and fill the gap with bark. The roots will grow into the new bark.

Watering
Orchid do not like to sit in water at all. So never put a saucer under the pot.

Orchid roots are covered in a layer of tissue much like blotting paper. This soaks up water and holds it for the root to access. To work properly this tissue has to dry out between waterings.

There is no need to water orchids sitting outside in a sheltered situation (under a deciduous tree is good) unless there are drought conditions.