The flowers beginning to open.
This green cymbidium which I called Cymbidium California 'Sun Acres' is blooming like crazy right now. There are five spikes arising from one plant; each spike bearing at least 12 to 16 flowers. Compared to last year when the same plant showed only one spike with seven flowers, this year's flower yield is dramatically more. The difference in the vigor of the plant could be attributed to the following factors:
1. Age. The plant has grown more since last year. In orchids shoots and pseudo-bulbs result in more flower spikes.
2. Fertilizer. Complete fertilizer was applied twice during the growing season. This orchid is responsive to fertilization both in terms of growth (shoots) and flowering (spikes).
3. Light. The plant has been placed in an area (south-facing) where it was getting sunlight as opposed to the previous year when (because of my lack of know-how) I kept the cymbidiums in the most shady part of the garden.
4. Orchid mix and Room to grow. The plant was transferred into a bigger pot with new and fresh orchid mix that I formulated. The formula seemed to work and the increased pot sizes probably increased root growth.
4. Differential temperature. This is the difference between the maximum (day) temperature and the minimum (night) temperature that the plant is exposed to. Flower initiation in cymbidium is mostly a function of differential temperature. Depending on variety or species, 10-20 degree-difference is required before flower initiation begins. The current southern-exposure location provided a longer time for the plant to be exposed to a sharper differential temperature. One reason why cymbidiums kept indoors do not bloom is that the growing temperatures are kept almost constant.
5. Visibility and Proximity. As they say, "out of sight out of mind", plants that are not seen often tend to be less cared for. The cymbidiums were moved into an area next to the back door where I could see them while doing the dishes. Seeing them reminds me more often to attend to their needs (water and fertilizer). Although the plant is tolerant to some degree of harsh growing conditions, it responds positively when environmental stresses are alleviated before they reach critical stage.
Cymbidium is an outdoor orchid; for optimum flowering, treat it as an outdoor plant.