Originally Posted by
raybark
Expanding on Roy's reply, in truth, there is no fertilizer that "boosts" blooming. That whole concept came about either as a misinterpretation of data or as a marketing myth (or both).
When the first "chemical fertilizer", Miracle Grow 30-10-10, was developed at Rutgers University and marketed, folks poured in on heavily. Their plants grew great, but after a while folks started noticing their plants not blooming as well as they had in the past. Another formula was developed, having decreased nitrogen and enhanced potassium, and - Lo! And Behold! - reasonable blooming levels returned. That formula, therefore, was marketed as a "bloom booster".
What folks didn't grasp (or possibly admit) was that it was the excessive application of nitrogen that had suppressed the blooming, so the second formula didn't actually "boost" anything, but by diluting the nitrogen content, it no longer suppressed it, allowing the plants to bloom normally.
The facts are that, while nitrogen is - by far - the most important mineral nutrient, a plant doesn't need very much of it - about 5g of NPK (90+% of that being N) and around 100kg of water are necessary for a plant to gain 500 grams of mass - and that given that minimal amount of nutrition and the proper culture, a plant will bloom to its genetically-programmed maximum capabilities. Any shortfalls detract from that.