Super thrive has been exposed as snake oil,it has not shown any evidence at all in clinical trials to do anything to promote root growth,make healthier plants or to lesson the shock of transplant,your better off using that $10 on good fertilizer because super thrive will not do one single thing to make your plants healthier.
From the University of California about Superthrive.
" Does vitamin B1 help transplants take root?
From: Sunset | Date: May 1, 1992| Author: Swezey, Lauren Bonar | COPYRIGHT 1992 Sunset Publishing Corp.
FOR MORE THAN 50 years, vitamin B1 (thiamine hydrochloride) has been touted as a cure-all for transplant shock. Labels typically claim that B1 aids rooting and growth of a wide range of plants.
But University of California research on vegetables failed to prove that B1 reduces transplant shock or stimulates root development. Researchers found "no discernible differences in color or vigor among treatments" when B1 and B1 plus iron, manganese, and zinc were used on peppers, pole beans, squash, sweet corn, "