|You'll read and hear about the use of "Bloom Boosters" or
"miracle" fertilizers or additives, or even special growing media that
promise to make your plants grow and bloom better. The reality, however is
there is no such thing as a booster!
If you, as a grower, do everything right - light levels,
duration, and periodicity, temperatures and temperature variation, humidity,
air movement around the plant and its root system, nutrition and watering -
you allow the plant to grow and bloom to it's maximum potential. There is
nothing you can do that overrides genetics in that respect. On the other
hand, any cultural shortfalls can, and likely will hinder the plant from
reaching its potential.
Using the example of high-phosphorus, so-called "bloom booster" fertilizers, they are marketing hype and not much more. A plant will only use as much phosphorus as it needs - which isn't all that much - and exposing it to more does nothing. In fact, studies have shown that it is excessive nitrogen that "quashes" blooming, not that another product "boosts" it. To overcome that, fertilizer manufacturers add inexpensive phosphorus minerals to ordinary, high-nitrogen formulas in order to dilute the nitrogen content and relieve the suppressing effect.
A further comment: sometimes when you hear glowing comments about that "miracle" product, the reporter doesn't realize that a shortfall was remedied. For example, when the "MSU" fertilizer formulas hit the orchid-growing scene, many new users were simply "astounded" at how much better their plants grew and bloomed. In fact, that had little to do with the fertilizer, but due to the novelty factor, they suddenly began to pay more attention to their plants and fed them on a regular basis, rather than the "hit or miss" method they had previously been providing. In other words, they were giving their plants what they needed to live up to their genetic potential.
The same is likely the case of special mass-marketed media blends. Certainly many of them are really good for some plants under some growers' conditions and watering habits, but it is equally certain that they are not "magic". If your plants grow better for you after you switch to one of them, and your culture has not appreciably changed along with that (reference the last paragraph), then I would bet that either your former medium was not correct for your conditions, or it was badly in need of replacement, and your plant is simply responding to the relief from the stresses that had been in place.
One exception to the "no such thing..." comment is that of rooting hormones. If properly applied, they do, indeed, stimulate the growth of new roots, enhancing the plants' ability to take up nutrients and water, making them stronger plants capable of dealing with stresses better. I a the case where the plant's root system was deficient in the first place, it can be a real boon to rescue and recovery.
That said, storing them and applying them correctly is essential, as warmth and light can cause them to deteriorate in the bottle, rendering them ineffective, and too-frequent or excessive use of rooting hormones has been shown to be detrimental to plant growth and blooming in some cases. Read more about such products HERE.