Kings Plant Barn has contacted customers about a security breach to FlexBooker, the internet-based system it uses to organise click-and-collect bookings.
Names, email addresses and collection times were exposed. But the gardening chain says no credit card, password details or mobile have been spilled.
On January 7, the US-based firm revealed a group of hackers had stolen data on December 23. The cyber-heist saw details from some 3.7 million accounts compromised.