B&Q's show garden, designed by architect Laurie Chetwood, "highlights the environmental differences every gardener can make, through an 8m vertical living wall of window boxes, demonstrating vertical farms and urban food production", according to the retailer.
Homebase's garden is designed by Thomas Hoblyn and features seaside plants from Cornwall.
Meanwhile, Bunny Guinness's M&G kitchen garden features fruit and vegetables. RHS show manager Alex Denman said: "You could say it is a bit old but growing your own is what people want to do."
Sarah Eberle's Monaco garden will feature a swimming pool and is due to be visited by Prince Albert, which "shows what Chelsea means", said Denman.
The great pavilion has more sponsored gardens than ever, with Westland sponsoring Hardy's 12x12m display, Bulldog Tools sponsoring Jon Wheatley's forge design, Scotts Miracle Gro sponsoring Hillier and Nomura sponsoring Kelways' 160th anniversary peony valley garden.