The water must wash through and around the roots. The coarser the medium, the more often a plant will need to be watered. Fertilizer Fertilizer must be provided throughout the year. Orchids, of all kinds, in bark cannot utilize nitrogen that comes from urea, so read your fertilizer label and avoid. Healthy, actively growing cymbidiums are heavy feeders in the summer and should be fertilized regularly if a slow release fertilizer is not used.
Some people use high-phosphorus fertilizers in the late summer to promote bloom spikes.
Potting Mix Cymbidiums do not grow in soils in nature but as epiphytes with roots exposed or in decaying timber and leaf litter. Straight standard fine fir bark is recommended. You may add small lava rock or perlite if you wish. Adjust your watering appropriately. Cymbidiums in this climate are happy in straight bark.