An estimated £0.5m extra spend within the garden industry has been generated by the 10,000-plus HTA Garden Gift Cards that have been sold since the launch of the scheme at the end of last October.
The HTA says the 10,000 card sales represent a minimum of 10,000 customer visits generated to garden retail outlets.
Wilkinson's and Midlands Co-op have both recently joined Sainsbury's and WH Smith in selling the cards, which can only be spent in participating HTA member outlets.
David Butler, HTA Garden Gift Card manager, commented: "We're confident that the HTA Garden Gift Card is driving new business into garden centres and nurseries. The £0.5m generated is additional money that's going into member businesses rather than the retail businesses that the cards are being purchased in."
He added: "The whole ethos behind the new gift card is to attract customers that wouldn't normally go to a garden centre to purchase the cards as gifts for family and friends.
"From our research there's no evidence to suggest cannibalisation of National Garden Gift Voucher sales so far and so this is incremental business for the industry."
Almost 500 members are taking part in the scheme but more can still sign up to join the pilot.