All I see is
1998 - Scotts entered into a collaboration with the Monsanto Company to apply biotechnology products to the turfgrass and ornamental plants business. Under the agreement, Scotts and Monsanto agreed to share technologies, including Monsanto's extensive genetic library of plant traits and Scotts' proprietary gene gun technology to produce transgenic turfgrasses and ornamental plants.
1999 - Entering into the pesticide industry, Scotts completed agreements with Monsanto Company for exclusive U.S., Canada, U.K., France, Germany, and Australia agency and marketing rights to Monsanto's consumer Roundup herbicide products and for the purchase of the Ortho and related lawn and garden businesses.
No where does it say Monsanto has any shares/% ownership of Scotts and there for owns GH, Botanicare and Gavita. The thing is if you're worrying about Monsanto you wouldn't be using 95% of what is in the hydro industry with the connections and histories with most of the companies. Hell you wouldn't be using any lights as they're all made in China by companies that pay slave wages and pollute the environment.