Cheshire wrote that he supports UK growers and simply wants to harmonise payment terms across B&Q's business by increasing them to 90 days for growers.
Cheshire was responding to a letter from NFU president Peter Kendall, who wrote: "The NFU takes an extremely dim view of any retailer using its market power to wield undue influence with its suppliers."
Cheshire said growers could talk to B&Q commercial and marketing director John Colley if they had a problem. But NFU horticulture adviser Dr Chris Hartfield said the "fear factor" meant growers would understandably not "stand up and be counted".
BBC broadcasters have attempted to find growers willing to talk about their experience with B&Q, but they are reluctant. Radio 4's You and Yours programme has offered speech distortion to disguise growers' voices.
HW has spoken to several disgruntled growers who have felt forced to sign B&Q's 90-day payment terms. Hartfield said: "Plants do not sit on shelves gathering dust. Hence, growers are cash-positive for businesses like B&Q."