The company had already been using HTTPS URLs for basket and payment pages, but has now set them as standard across every page.
In doing so the company has joined only 21 per cent of the world's top 100 websites to currently do so, said marketing manager George Riley.
HTTPS is a protocol for secure communication over a computer network widely used on the internet and tightens up on the protection of privacy and integrity of exchanged data.
Managing director Ian Charles said: 'We're dedicated to offering our customers the most trustworthy and secure experience possible.
"Using secure servers across the site from the moment the customer lands to the point they complete their purchase is reassuring for internet shoppers.
"Google has been encouraging websites to adopt HTTPS everywhere and now Primrose is joining the forerunners in secure browsing."
Primrose has become one of the UK's biggest online gardening retailers since it started in 2003, specialising in water features, awnings, planters and a whole range of outdoor lifestyle products.
"Like our innovative waterproof shade sails, we like to shelter our customers both online and in the garden," Charles added.