The retailer offered the bogofl deal on pineapple, melon, salad and lettuce as part of a two-week trial in January this year.
Speaking at a Carbon Neutral Company seminar this week, Tesco corporate responsibility director Ruth Girardet said customers had "absolutely loved" the waste-reducing offer, especially single-person households.
"The challenge now is how to work this out commercially to deliver on a bigger scale," she said.
Tesco is also working on expanding its Carbon Reduction label, launched with the Carbon Trust in April 2008. "The label is now on 120 products," she said. "It has been difficult because it is a costly and long process. We need to find a way to move this to a bigger scale to 1,000 or even 10,000 lines. We then need to take a view of how we can use these findings."
It had been a challenge to engage customers on environmental issues during the recession, because customers were focused on price, added Girardet. "Thrift has become quite chic. Customers have become very good at reusing and recycling and we need to build on that."
Tesco was on track to reduce carbon emissions in its transportation by 50% by 2012 through the mantra "less fuel equals more fill", she said, and was also keen to work with suppliers. "We need to work with the supplier base, share knowledge and technology."
Tesco was "not currently considering" carbon offsetting but would not disregard it if it helped engage customers in green behaviour, she added.