The two events almost did not coincide after the RHS had doubts over whether it could host more than 80 journalists at its annual shows launch.
RHS head of press Lynn Beddoe said: "We were always looking at working with the gardening event. So we're going to do a short presentation looking at the year ahead and will also be holding a press reception at the London Flower Show (on 17-18 February)."
She added: "The difficulty was with taking journalists out of the event for the press conference. This will now be a more general presentation at lunchtime."
Up to 200 journalists are expected at the press event, to be held at Royal Horticultural Halls in London.
Organiser Richard Jackson said: "Hillier has signed up because of the RHS link. We could get over 200 journalists attending and for any company in the gardening sector that's good. Stands cost as little as £500, which must be an incredibly cost-effective way of meeting and communicating with our leading writers and broadcasters."
Exhibitors booked include Marshalls, John Woods, Palmstead, Sakata, Haddonstone, SpotlessPunch, Stihl, Suttons, Thomson & Morgan, Vital Earth, Vitax, Bradstone, Bosch, Ball Colegrave, BALI, Darby, David Austin, DLF, Doff, Farplants and Bulldog.