Professional Grower's Notes on Blooming Phalaenopsis/Phals
Diana in Houston nicely shared her notes under a thread called "Phal Insider Growers info." Arthur and others added information and had questions. The following is primarily Diana's editing of that original post. Thanks Diana!
I just came from my orchid club meeting where we had a local wholesale commercial phalaenopsis grower as the speaker. It was interesting but nothing special until he and Dr. Wang, our mentor and reknown orchid researcher, started talking about what was required to make phals bloom, and have more flowers, (a specialty of Dr. Wang's). Here's the scoop:
- A phal NOT blooming can be determined by temperature AND light. A commercial grower can KEEP PHALS FROM BLOOMING until a particular time by keeping the temperature above 82 degrees. However, a cheaper way is to shade the greenhouse with 50% shade cloth.
- To initiate spiking, the temperature must remain consistantly below 82 degrees. A temperature of 90 degrees, even for a short time, will prevent spiking.
- To have more flowers on a spike, from the time the spike is 2 inches, until it is 8 inches, the temperature must remain consistantly between 65 degrees and 77 degrees. Day and night difference is not involved. This commercial grower gets the phals as 4 to 6 inch bare root plants from Taiwan. He pots them in 4 inch pots and grows them on for about 6 months, at which time they go into 6 inch pots. He then keeps the benches of phals he wants to spike under plastic with an air conditioner (on 24 hours a day) at each end until the spikes are 8 inches tall (approximately 6 weeks). He then moves them out until they have 4 or 5 flowers open, then delivers them to jobbers.
As you can see in Dr. Wang's information above, withholding blooming to produce bigger and better blooming is standard practice in the industry. (Notice he says that growers raise the temperature to prevent blooming, but he added that greater shading will produce the same effect.) Nothing specific was mentioned about phal species. I would assume that the species that make up the modern hybrids would be responsive. I failed to mention that the commercial grower said that he stops the cooling when the spikes reach 8 inches, but that it was for economic reasons. He has the plastic cover on an arched frame about two feet above the benches. He could have it higher and let the spikes reach a greater height by cooling for a longer time, but it is better for him to have fewer flowers and be able to treat another batch of plants, then to have fewer plants, but more spectacular flowers. Also, Both he and Dr. Wang use RO water and cal/mag fertilizer exclusively. Doesnt the air conditioning lower the humidity? That question came up at the meeting. Larry said that, between the area being closely covered with plastic, and the regular watering schedule, (hand watered, not automated) the humidity did not drop low enough to affect the orchids. Posted by: ArthurM NSW AUST (My Page) on Sun, Aug 1, 04 at...