A mix of independent media and horticulture industry experts judged the new award which was presented at the guild’s sold-out Savoy Hotel awards event.
The judges described Horticulture Week as "packed with useful information and articles written with depth and understanding of complex subjects that impact our industry."
They added: "A masterclass in trade journalism, the reporting is well researched and delivered with clear authority."
"But more than that, the title celebrates the trade and its members in ways that makes them feel valued."
Sponsoring the Trade Publication of the Year Award was the industry trade show Landscape.
The Garden Media Guild Awards recognise the very best garden media professionals working in all areas from national radio and TV to digital and print media.
Other winners at the event included TV’s Gardeners’ World for a special broadcast on plastics use in horticulture, the Kitchen Garden which won Garden Magazine of the Year, writer Val Bourne who won the Dr Hessayon Columnist of the Year Award for her articles in Amateur Gardening magazine and Garden Design Journal's Stephanie Mahon.