Superthrive, K-L-N, and most other root growth stimulants contain synthetic auxins, which by themselves, are extremely effective. The problem is that in order to make them water soluble, they must be converted to mineral salts, and those are far less chemically stable. Dave Neal, who founded Dyna-Gro, once told me that a fresh batch, if kept cool and dark, wil be viable for about a year. If it is stored warm, that is decreased to a number of months, and if allowed to get hot or be exposed to sunlight (i.e., stored in a greenhouse, as many folks do), the life is reduced to a matter of weeks.
Considering it's made and warehoused in California, trucked across country to distributors who store it how and for who-knows-how-long, most of the stuff you buy is likely well short of "fresh" when you get it.
You want something that DOES occur in nature? Try Kelpak.
