Mariella,
Check the recent thread 'Cymbidium Temperatures" under the Cymbidium Alliance. There is a post there near the end on the temperature range for Cyms.
The problem you have is not just one of temperature change but one of keeping the plant inside too long during the growing season. No amount of temperature change or fertilizer can overcome the failure of a bulb to attain the proper size during the growing season for that plant to set a flowering spike. Cyms are outdoor plants in temperate climates. They need high light short of burning for best growth and flower production.
Next spring, when here is no longer danger of freeze, take your plant outside in a 50-50 shade-sun location i.e. morning sun-afternoon shade, restart your fertilizer program and watering for the outside location, and you should get a fully mature bulb(s) for bloom in 2010. I do not know how long the plant has been in its current pot but you may also consider repotting too.
Good luck,
CL
Threaded Mode
