My tomatoes are late to ripen this year, so last week I stopped at a farmers market in Imlay City to search for some good locally grown tomatoes.

Smaller farm markets are one of the few places I can find what are now thought of as old-timey tomato varieties, those that have the great flavor I remember as a kid: tomatoes such as ‘Rutgers,’ ‘Big Boy’ and ‘Early Girls.’ Today farmers usually prefer to grow what are known as “market tomatoes” — tomatoes that have been hybridized to withstand the rigors of packing and travel.

They remain firm to the touch even when ripe, which prevents bruising with handling. Their skins are red and blemish free and their size is consistent. But with all their good looks, these locally grown “commercial varieties,” though better than grocery store tomatoes, lack the rich taste of their older relatives. I scored at the Imlay City farmer’s market and drove home with a bag full of ‘Early Girls,’ some ‘Big Boys’ and a couple of gorgeous black Russian heirlooms, known for their rich flavor and smoky overtones.

The couple I bought my tomatoes from usually sell at the Saturday Royal Oak farmers market, but their crop has also been slow to ripen this year so for now it makes sense for them to sell at a smaller venue.

Lots of folks, including myself, find their tomatoes are slow to ripen this year and the culprit is the heat.

According to Cornell University researchers, the optimum temperature for ripening tomatoes is 70 to 75 degrees. When temperatures hit 85 degrees or higher, the ripening process slows significantly or may even stop. At these temperatures, lycopene and carotene, pigments responsible for giving the fruit their typical orange to red appearance cannot be produced. As a result, the fruit stays in an immature green phase.

Resist the temptation to fertilize the tomatoes now as doing so will only stimulate new growth and slow the ripening process even more.

Tomatoes that have begun to show color can be removed from the plant and taken indoors to ripen. They don’t need sun to mature so you can store them on a shelf or counter. Many folks say the flavor of the “indoor ripened” tomatoes is as good as those ripened on the vine.

Thinning out the number of tomatoes left on the plant will also speed up the maturing and ripening.

Medium to large tomatoes take many weeks to mature, so removing new flowers and smaller fruit makes sense

Nancy Szerlag is a master gardener and a Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to and click on Ask Nancy. You can also read her previous columns at

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