Getting a Phal to bloom in Caribbean
 

Hi

I'm doing exceedingly well with dendrobiums, but phalaenopsis are giving me a challenge. Mostly, they look very healthy, but won't produce flower spikes. I have been reading a lot about how temperature affects blooming. I live in the Caribbean. My temperature hardly ever falls below 25C in the middle of winter. Is all hope lost for my phals?

I am currently trying a little experiment by leaving one phal in an air conditioned office, by the window. Around 22/23C Maybe that will encourage blooming?

Attached is an example of one of the phals.

Maybe I should stick to dendrobiums only 😕.

Any advice (particularly from those in hot climates)appreciated!

Let me add. They all get morning sunlight for about 2 hours. And indirect light the rest of the day. I feed with miracle gro 30-10-10 maybe once weekly.

I think that the issue may be light duration. I went from "not much blooming" to about 80% by adding supplemental lights 12 hours a day (on a timer) I have never particularly chilled my Phals... commercial growers do that to control the timing of blooming (the orchid that blooms just before Christmas or Mother's Day is worth more than one that blooms two weeks after) For hobby growers the timing is not so important.

Average temperature drop and slight light increase in Fall trigger flowering independently. Since controlling temperature would be difficult, I suggest you grow them in less light most of the year, and give more light in October/November. Move them away from the morning sun into medium shade for most of the year. In October move into more light for 6 weeks, then back into less light.

Ohhh ok then. Interesting. Varying durations of light. Food for thought. I guess I'll have to tough it out and keep trying things. Thanks for the ideas so far.

HOW MUCH 30-10-10 weekly? (Real numbers, please, not nebulous stuff like "half strength".)

Excessive nitrogen can also quash blooming.

Tbh I haven't been very technical with it. The package said 1 tablespoon for a gallon. Some weeks I used that. Others I used about half tablespoon per gallon. Hope that clarifies it.

I agree with the others. Cut back on the fertilizer a little and try to give them nice bright low light for as much of the day as possible. Some sheer curtains can do wonders.

Cut back on the feeding A LOT!

Quick rule-of-thumb: for any fertilizer, divide 8 by the %N in the fertilizer; the result is the dosage for weekly feeding, in teaspoons/gallon. In this case 8/30=0.267, so 1/4 tsp/gal weekly is far more appropriate.

If the plant has been excessively fed for a while, It may take many months at the lower rate before the bloom-quashing will subside.

How much is a tea spoon in the USA?