I may not be much help here. But I used to worry about fertilizer cycles too.

But as the collection grew, it became impossible to keep track of which plants needed the "red", "blue" and "yellow" fertilizers.

So now they all get the same 20-20-20 fertilizer across the board :)

That is the problem in a nutshell. If you have enough orchids of different kinds some will be blooming while some will be growing.

Just use a fertilizer with a higher Nitrogen number in Summer and a lower number at other times.

Here.... Lc. Fire Dance blooms in spring from sheaths made in Summer/Autumn. My plant is in the shadehouse enduring what passes for winter. It is currently 5C at 07.00 and the plants in that enclosure are getting Nil fertilizer.

I third that. Mine generally get what the majority of them should get. I am just going to switch over to bloom myself. I use Age Old Organics and there only is grow or bloom. I use it in bins and use the leftover on my other non-orchid plants.

Use the bloom booster fert. every fourth time you fertilize the plants. I've done this for years with good results.

For orchids that go through a winter rest period (many) the change in fert. will trigger the plant to start the processes of slowing down and going into 'resting' mode. Thus a good time to switch is at the end of summer/early Fall. And a good time to restart the high nitrogen fert. is when you start to see new growth in the spring or after the blooms fade ...for spring bloomers.
-MB

One way to approach the question is to understand how each type of fertilizer acts upon a plant. That high nitrogen supports increased growth occuring with increased light and warmer temperatures is generally recognized. What is less understood by many hobbyists (myself included) is the purpose of so-called blossom boosters.

What they don't do is induce a plant to bloom, or increase the number or size of flowers. What they do do, according to some reports, is to enhance substance. Flower production, the number and size of flowers depends first on genetics, second, on the overall health of the plant and third, cultural conditions that directly affect bud development.

Phosphorus hardens plant tissue. In nature, the 'typical' epiphyte receives at some point, several weeks of sunny dry weather that "cures" new foliage, and the relative dryness after the growing season often triggers blooming. Additional nutrients of any kind are minimal.

In temperate growing areas, it may be beneficial to assist this hardening process with additional phosphorus since our sun tends to 'disappear' as days shorten and skies become cloudier.

If a balanced fertilizer such as 20-20-20 is used during growth, it, at any rate, should be decreased or even ceased altogether after growth is complete. A regularized extra dose of phosphorus from blossom boosters during the ensuing non-growth period is far from critical.

If a high nitrogen fertilizer such as a 30-10-10 is used (somewhat uncommon among hobbyists), producing maximum growth in warm, sunny growing conditions during summer, an increase of phosphorus and corresponding decrease of nitrogen after growth is complete could aid in hardening. But it is for the support of general plant processes, not just the production of flowers, that this regimen is employed.

That's my understanding of the issue, at any rate.

John :>)

P.S. The dynagro formula you mentioned is already less than 'half-strength' out of the bottle. Consider switching to a granulated fertilizer with trace elements that you mix yourself. You'll save money without loss of quality.

Thanks to all of you. I think for my purposes, Arthur's suggestion of high nitrogen in the summer, and not at other times is the simplest and makes sense to me. I was talking to my grandfather, who informed me that the phals he has had for years have never been fertilized. He just sets them under a running faucet for a few minutes once a week. Kind of makes me wonder how much a bloom fert really performs over a standard one, given good culture. Thanks again, Bob.

>>Kind of makes me wonder how much a bloom fert really performs over a standard one, given good culture.

I do not know if there is a certain saturation level with orchids where it has acquired the maximum amount of a specific nutrient that it needs for flower production.
Does the plant actually say "I have enough for this season's flowers. No more please".

I also am not sure if a plant will continue to absorb the nutrients even after it has reached that saturation point and store it as chemical energy for future growth, or if it simply discards it back to the environment.

So if there is in fact a saturation point, then a plant grown in ideal conditions is probably close to that point already. A "bloom" fertilizer (or any fertilizer for that matter) may be inefficient then since the plant only needs to take a small portion of what the fertilizer is giving.

Of course, diluting the fertilizer solution would compensate for this and actually make more efficient use of the fertilizer.

Thanks, this information really help me, but (I'm a little slow) which fertilizer should I use ? tell me brands please, so, I can look for them here in Mexico. thank you

You probably won't find many people here willing to research which fertilizer brands are available in Mexico. I can guess....Los Peters, El Miricle Grow, maybe...DynaGrowito?

You can use any brand. If you're going to fert with every watering, use a low concentration, balanced fert. With numbers like: 6-6-6 (same numbers=balanced; low numbers=low concentration). Otherwise I'd probably use one with higher numbers and higher nitrogen and stop using it completely in the Fall and Winter.
-MB

You might consider switching to an MSU formula. It can be used year round, just using less in the darker months.