Cattlyas not flowering

Insufficient light?
Insufficient food?
Too much nitrogen?

 

When my Cattleya plants don’t flower it’s either because of insufficient light or because of lack of pronounced day/night variations. Long warm summer days can be a disaster for some Cattleyas.

 

How much fertilizer per gallon?

How much light does it get in the daytime? I assume it’s in a window, so what direction does it face?

 

The plants sold as "Cattleyas" nowadays can have all sorts of ancestors and therefore even if they look similar, they can have different needs. If you know the name of your plants that could give a clue to their needs.

 

The mention of exposure to light all night jumps out at me as a possible factor. Some Catts really need a dark period at night, and may not bloom if they don't get it. Some are less fussy. So possibly, all other things being equal, the ones that are less in need of a dark night may have been the ones that bloomed. If they have been moved to an area that doesn't get light all night, that could help for some of those.

 

I am not asking the ppm. What is the formula (%N, P & K), and how much (g, ml, teaspoons, whatever) do you had to a liter or gallon of water.

You asked for help, but seem hesitant to share the facts we need to do so.

 

Hah! Laughs on me then, and I apologize. I really SHOULD wake up before responding!

However, we still don't know how much is used per liter... My recommendation would be 1.3ml/L.

 

JPL,
Ray has a website that is very informative, if you care to read up. If you don't have the time, he has fertilizer calculators that does the math for you.
Welcome to First Rays! » First Rays LLC

 

That much of an 8%N formula is applying about 350 ppm N, which is a LOT of nitrogen. I’d recommend no more than 100-125 ppm N weekly. Excessive nitrogen can lead to great growth, but definitely can quash blooming.

The “dosing factors” of any fertilizer formula are 10.4/%N on label give ml/L for 100 ppm N and 13/%N gives ml/L for 125. With your fertilizer, I would use about 13 ml/9L

 

The most important to gets flowers by Cattleya is the day / night temperature difference. At day 35 sometimes 40 degree, and at night max. 15 to 17 degree.
I mixed a lot of diffrent fertilizer., so I doesn't realy know what is the composition.
The most Cattleya's needs min. 350 ms weekly, with exception of Sophronitis. This one max. 250 ms. I fertilize 3 weeks in a row once and then one week only with rain water.
The substrate must be rinsed in order not to become too salty. Then Cattleya needs min. 10 hours Light. I have a LED-Light to have a long day with 12 hours. This is the absolutly maximum. Then the plants needs rest in dark.