There is no such thing as a bloom-boosting fertilizer; it is all and extension of marketing hype and much spread lore.

Back when Dr. O. Wesley Davidson of Rutgers University invented Mir-Acid (30-10-10) - one of the first "chemical" fertilizers - it was recommended for orchids, as the high nitrogen level increased its acidity, something orchids like, up to a point. People used it at a pretty heavy dosage rate, and noticed tremendous growth, and a "star was born".

Unfortunately, over time, folks started to notice that their plants weren't blooming well, if at all.

More research was done, and it was discovered that excessive nitrogen application can quash blooming, so the formulator threw in extra phosphorus, effectively diluting the nitrogen, and - lo & behold! - folks plants started blooming again months later. Marketing got hold of it and the "Bloom Booster" was born. In fact, it does not "boost" anything, but by reducing the levels of nitrogen applied, it "allowed" the plant to bloom normally.

So, back when folks routinely overfed their plants, switching to the low-N/high-P formula for a couple months in anticipation of the normal blooming period for the plant, removed that burden.

The fact is this: Give your plant all of the cultural parameters it needs, don't overdo anything, and it will bloom to its maximum, genetically-programmed capability.

---------- Post Merged at 07:55 AM ----------

Let me add to that a little.

I was always of the impression that the formula is what determined if you were feeding "high" nitrogen or not. I've since learned that it isn't the formula of the fertilizer that's so important (it is, but to a lesser degree), it's the amount-, and frequency of application.

If you think of the mass of applied fertilizer minerals as being analogous to calories when we eat, it's easier to grasp.

In nature, most orchids will see no more than 15-25 ppm dissolved solids cascading down on them from the forest canopy as it just starts to rain. They may get that several times a day - frequent, periodic "snacks". It's mostly nitrogen, but at that low amount, there's no issue. Then there is the average in-home grower...

The plants are fed once a week, and using a good general orchid fertilizer - the original MSU formulation (19-4-23) - at the often-recommended 1/2 teaspoon/gallon, and you're applying somewhere in the neighborhood of 800-900 ppm of dissolved solids, and around 125 ppm N alone, roughly 10x what the plant sees in nature. That's sort-of like starving yourself for a week, then gorging at the local all-you-can-eat buffet. Which is healthier? (For you, or the plant.)

I now exclusively use K-Lite fertilizer (12-1-1) on all of my plants, and that, from a formula perspective, is one of the highest nitrogen formulas out there. However, I apply it at about 25 ppm N every two or three days, depending upon the weather (sunlight levels), mimicking nature, and I am seeing some of the best growth and flowering I've ever experienced in 40+ years of growing.