There’s nothing wrong with a Cortland apple that’s a bit small and has a blemish or two. It’s still an apple and tastes pretty much the same as all Cortlands do. There’s nothing wrong with carrots that aren’t as thick around as a shower-curtain rod. And there’s nothing wrong with corn that isn’t as golden as a school bus.

Maine’s farmers have been trying to make those points to Hannaford Bros., owners of the Shop ‘n Save supermarkets, and Shaw’s Supermarkets. And it’s not that those grocery chains aren’t hearing the argument, or even agreeing — they sell some locally grown produce on a seasonal basis.

The problem, simply put, is that supermarkets have trouble selling a tomato that isn’t candy-apple red, spot-free and as big as a fist. Consumers simply won’t buy produce that is small, blemished or otherwise appears to be substandard to fruits and vegetables imported from other places.

For that, the supermarket chains can’t be blamed. They need to sell what people will buy.

While it’s easy to understand how that can frustrate farming interests such as the Maine Organic Farmers and Gardeners Association, as recent news reports have indicated, the task lies with them to change Mainers’ attitudes about Maine-grown produce. Fortunately, there are compelling arguments.

Maine-grown produce is fresher. In many cases, the fruits and vegetables grown here contain fewer pesticides and fertilizers, have not been genetically altered or harvested in unsanitary conditions. Better yet, helping Maine’s farms helps Maine’s economy and preserves open space, which comes under increasing threat every day.

Until Maine’s consumers can learn those lessons — both the state and private organizations have lots of opportunities to act as teachers on these subjects — and be shown that produce which isn’t abnormally large and blemish-free can taste as good, or better, than imported food — it does local farmers little good to blame retailers. They can sell only what sells.