Per the manufacturer, FoxFarm BushDoctor Boomerang is also safe to use during the flower stage.
FoxFarm BushDoctor Boomerang assists in rebuilding damaged plant root tissue, and allowing for new root and vegetative growth. It helps stressed plants recover quickly from temperature fluctuations and mineral salts with the solubilized organic nutrition included in the product's formulation.
For further questions and clarification regarding your specific question, we suggest reaching out to the manufacturer directly for product support. FoxFarm can be reached by calling 707-443-4369, emailing foxfarm@foxfarm.com or by visiting their website's contact page here.
